Some here at CC are accomplished mechanics, whether as professionals or as hobbyists. Others of us, while mechanically inclined souls, are no threat to those who keep our cars running for a living. I place myself in the second category. From a clueless teenager who was shocked to find a clip on the back side of a screw which attached a piece of trim to the body of my ’67 Ford I have progressed to the place where I consider myself a reasonably competent twister of wrenches on basic repairs. I suspect many readers here inhabit this space along with me, or perhaps will with more practice.
We had a recent discussion here about an ’89 Thunderbird. This car resonated with me because I owned another car with a similar powertrain – a Fox body 1986 Mercury Marquis station wagon. Beyond the fact that I liked the car a lot, it reminds me of one of my great triumphs as a diagnostician of automotive ills.
I purchased the car at a tent sale which east side Indianapolis auto dealers had set up in the parking lot of one of the city’s malls. I had been looking for an inexpensive second car to replace my 83 Colt which had just been wiped out in a collision. One of my rules of used cars is that the best buys are cars that are unpopular not because they are bad, but because they are out of style. I knew that following the debut of the Taurus and Sable, those ugly duckling versions of the Fox body had become a great choice as a decent but cheap used car and I went looking for one. The one I bought was not terribly old (five years) but had fairly high miles for the time at about 106K. It was one of my more enjoyable cheap cars and was quite luxuriously equipped for what I paid with very few option boxes left unchecked by the original buyer. Put wire wheelcovers and a chocolate brown “Brougham Decor Group” interior with the picture above and this was my car.
Photo source: Wikimedia commons
One morning made me start worrying, however. I started the car and pulled away from the curb as I always did. After a two block stretch on my street I stopped at a stop sign, preparing to make a right turn onto a busy thoroughfare. I stepped on the gas and . . . not much. The engine revved but the transmission seemed quite uninterested until it decided to bang into first gear off we went. “Damn” I thought, “this is all I need – a transmission rebuild that may double my investment in this car”. I knew how that would play with the finance committed at home.
I knew to check the fluid first and found it to be very, very low. A bottle or two of Mercon took care of the problem but I knew that there was a bigger issue because that fluid had to go somewhere, a fact driven home to me two or three weeks later when the issue repeated itself. The car did not seem to be leaking fluid, so just where the hell can transmission fluid go? The radiator was an obvious possibility, but there seemed to be no contamination of the coolant.
I knew that oil goes away by either leaking or burning, but could transmission fluid be burned? I was inspired to disconnect the biggest vacuum line I could find where it went into the intake and I’ll be dipped if it was not coated inside with slippery red Mercon fluid. I knew that vacuum was involved in the operation of Ford automatics and quickly figured out that I had a bad vacuum modulator. A little research revealed that my transmission was a C5 (instead of the C4 that I had assumed it to be) and a trip to the parts counter and a session on my back in the driveway had my transmission back in top shape, apparently none the worse for wear from being starved for fluid.
Looking back I remembered noticing a little puff of smoke upon startup for the previous couple of months. That had not been (as I had wrongly assumed) my high mile 3.8 getting a little tired but had instead been my engine slurping transmission fluid through a bad diaphragm in the modulator. Who needs Marvel Mystery Oil for lubricating those upper cylinders?
Boy was I ever proud of myself. I had just diagnosed and inexpensively fixed an automatic transmission, something that I imagined few others could (or would) do. That experience bolstered my faith in my mechanical abilities by no little bit and taught me that most of this stuff is not rocket science. Instead it is reasonably simple for someone with some patience, some tools and willingness to do a little thinking. I will also admit that this sort of thing is a lot easier with the internet, which offered me no help in 1991. I still take my daily drivers in to the mechanic for most real repairs but do my best to diagnose a problem before I go there. I am correct in the cause of a problem more often than not.
So how about you. Is there an automotive repair diagnosis that you have made and remain especially proud of? And for those real mechanics who may be tempted to chuckle and pat me on the head after reading this, hey, we all have to start somewhere, and you guys will probably have the most fascinating stories of all.
I’ll tell you what happened today.
Son’s ’93 Accord – which looks like a dead ringer for the pic on the “Peak Accord” post, except for “Honda rust” around the rear wheelwells and a few dents and dings – wouldn’t start.
I figured it was an electrical issue since…
1) The ignition system’s a little moisture-sensitive when it hasn’t been run in more than a day…
2) We’d had a lot of rain and drizzle the previous 36 hours or so…
3) He had the previous day off and didn’t drive it.
We took a hair dryer to the cap, coil and plug wires for 3-4 minutes…took right off.
I’ll be happy when he can afford a ride with coil packs, LOL.
You remind me of another of my now-obsolete tricks as learned on old moisture-sensitive Mopars. A little WD-40 sprayed in the distributor cap (and in the wire terminals if that doesn’t work) will do wonders for displacing moisture. That said, I have never tried it with a Honda (never needed to) so YMMV.
In fact, the WD in WD-40 stands for “water displacement”. It was intended to be a rust preventer, not a lubricant.
I guess my cars have been too reliable; I haven’t had all that many problems to fix. I guess there was the time that I replaced the backup light switch in my Saturn. The backup lights weren’t coming on when I put the car in reverse (a problem that tends to confuse other drivers when you’re backing out of a parking space). I figured it was pretty unlikely both bulbs would burn out at the exact same time, but I figured I should eliminate the simplest solution. Sure enough, it wasn’t the bulbs. Now this is where most people would say the switch is the only other possibility and just replace it, and they would be right. But the engineer in me had to test the switch first. I got my digital multi-meter and checked the continuity, and sure enough, open circuit. But I didn’t stop there. I decided to make sure the rest of the circuit was good, too. I bypassed the switch with a piece of wire to see if the lights would come on then, and they did. So long story short I got a new switch and it fixed the problem. But I was absolutely sure, darn it.
Ok, I intended for this to be its own comment an not a reply to this one, and I’m pretty sure I did (I distinctly remember seeing Dave Skinner’s post above mine as I was typing). But it seems the site hiccuped and it ended up here instead.
I did get the 503 error both times I commented. I’m guessing something didn’t get finalized the first time I commented, and the system got confused when I wrote my second comment and it thought I was still replying to J P Cavanaugh and put my comment here.
Great question JPC, gosh there have been so many.
My first effective diagnosis ever was holding the choke plate open so a flooded car could start. I was 12, and the car was a rent-a-wreck 1972 Mercury Marquis that Dad had for some reason. I learned that trick from an Encyclopedia Brown: Boy Detective book I had read.
My best diagnosis was the first year I was married, Mrs DougD was driving her Mercury Topaz in downtown Toronto with me and another couple, I think the guys were in the back, we were going to the Theatre District to see a play.
Traffic was crawling along, and although it wasn’t a particularly hot day the temperature gauge on the Topaz kept creeping up, eventually we were at the point of blasting the heater with the windows open. It was right on H when I had an epiphany and said “Put the Air Conditioning on!”
The ladies thought I was nuts but tried it and sure enough the needle began to creep down. The temperature switch for the cooling fan had failed and putting on the AC ran the fan all the time.
After the play I jumpered the switch with a paper clip and drove it like that for a few days until we got a new switch. It was a perfect diagnosis because not only was I right, but my answer came at the last possible dramatic moment so I really looked like a smart guy in the eyes of my new bride.
Now that she knows me better she would say “Well, why didn’t you think of that before, Mr Engineer?” 🙂
“Aw, heck,” said Encyclopedia Brown, “It was just a stuck butterfly valve.” I remember that one!
1988 BMW 735i. It was running like crap. It started out by bucking at idle and stalling, and then it just stared to buck all the time. Thing stank of gas and smoke would pour out of the muffler. I figured it was leaking fuel injectors, so I pulled them and replaced them with some GEN III injectors. Sure enough, it ran just fine.
I bought a VW from my brother who replaced or rebuilt the carb several times in a vain attempt to fix a run on problem. I saw a strange electric device on the carb (something my older VWs didn’t have) turned out it was to prevent engine run on. It made my brother mad that this $10 switch solved his long time problem.
I can’t think of any one particular thing but it does bring to mind the interaction with customers over the years when I’d figure out a problem (that often had previously been attempted to be fixed unsuccessfully by others) in a few minutes or seconds. One the one hand there were those that happily payed me the $75 for my 5 minutes of work while others would balk and reply but it only took you 5 minutes and you want $75??? To that I’d usually respond “No it took me over 20 years, AND 5 minutes to fix it” and follow it up with “Don’t be mad at me for charging you $75 to fix it, be mad at the guy that charged you $150 to not fix it.”
You remind me of a story by the late physicist Richard Feynman in his biography, “Surely You’re Joking, Mr. Feynman!”. When he was a kid in the Depression he would do side jobs fixing people’s radios. This one job was for someone who kept putting him down for just being a little kid who claimed to fix radios. His radio would make noise when it was first turned on, then it worked normally……
But when we got there I went over to the radio and turned it on. Little noise? My God! No wonder the poor guy couldn’t stand it. The thing began to roar and wobble-WUH BUH BUH BUH BUH-A tremendous amount of noise. Then it quieted down and played correctly. So I started to think: “How can that happen?”
I start walking back and forth, thinking, and I realize that one way it can happen is that the tubes are heating up in the wrong order-that is, the amplifier’s all hot, the tubes are ready to go, and there’s nothing feeding in, or there’s some back circuit feeding in, or something wrong in the beginning part-the RF part-and therefore it’s making a lot of noise, picking up something. And when the RF circuit’s finally going, and the grid voltages are adjusted, everything’s all right.
So the guy says, “What are you doing? You come to fix the radio, but you’re only walking back and forth!”
I say, “I’m thinking!” Then I said to myself, “All right, take the tubes out, and reverse the order completely in the set.” (Many radio sets in those days used the same tubes in different places-212’s, I think they were, or 212-A’s.) So I changed the tubes around, stepped to the front of the radio, turned the thing on, and it’s as quiet as a lamb: it waits until it heats up, and then plays perfectly-no noise.
When a person has been negative to you, and then you do something like that, they’re usually a hundred percent the other way, kind of to compensate. He got me other jobs, and kept telling everybody what a tremendous genius I was, saying, “He fixes radios by thinking!” The whole idea of thinking, to fix a radio-a little boy stops and thinks, and figures out how to do it-he never thought that was possible.
Great story. Reminds me of an old saying “you have to be smarter than the thing you are fixing”.
This reminds me of a story about a guy who fixed a problem with a single smack of a hammer and that ends with the guy re-doing the bill to say “Hitting with a hammer – $5. Knowing where to hit – $70.”
The one that comes to mind was my ’87 Mustang with a 2.3 Lima four in it.
Heading home from work, I hit the highway and quickly lost power. I pulled off into a rest area, and checked some basics, but quickly realized I was in the no tools, no hope zone.
A call to the wife got me home, and the next day I came up with a full tool box. Air, fuel, and spark all checked out, but the timing had jumped about 30 degrees. Rotating the distributor got me going, but clearly something was amiss-
I headed back to the shop to figure out the root cause, and along the way, had to stop to dial in more timing. Much like Richard Feynman (see the post by MikePDX), I stood back in the shop and visualized the internal workings of the camshaft and distributor drive. The camshaft timing remained in time, so the issue narrowed down to the secondary shaft or the distributor.
Picturing a parts blow up of a distributor, it suddenly jumped out at me- The distributor gear locked in place with a roll pin! I removed the base clamp, pulled the distributor, and found the gear was on the shaft but out of phase. Time and cost- about 30 minutes and 85 cents for a new roll pin (plus travel time and an annoyed wife).
I still remember the sense of satisfaction I had when I removed the distributor and confirmed the roll pin was AWOL- It may have been the first time I nailed down an obscure root cause based strictly on symptoms and observation.
My first: My dad’s fairly new Renault R 4 quit running, like it was out of gas. A friend of his towed it in the driveway. I looked under the hood, couldn’t see anything out of order. I went around and removed the gas cap. It made a whoosh sound. After that the car ran again. The vent hole was not open from the factory and the cap was completely sealed. My dad took it to the shop and they drilled the hole open.
My best, I think: I helped a guy on a Mazda enthusiast group getting his Mazda MX-3 GS running again. That engine has a finicky variable intake manifold system and over a few weeks I helped him figure out all the gremlins. I learned a lot myself because I never even saw an engine like that. Still haven’t seen one except in pictures.
I had an R5 that did the same thing somewhere around Fredericktown MO on a Saturday morning. It actually sucked up the bottom of the gas tank, creating a dent, which was later (somewhat) blown out with compressed air.
A couple of years ago I bought an ’87 Jetta GL for $700. It was in really good condition for it’s age, needed some rear brake work, a drive axle and lower wishbone which replaced.
Bought it in the summer and it always started right up, as the weather got colder it was harder to start, once the temp dropped lower than about 40 F it just would crank, but not fire. Found with a checklight no power to the cold start valve when cranking the starter. Couldn’t trace down the fault in the wiring, so made a mini harness direct to the valve, now the test lamp flashed when starter was engaged. Next cold night, cranked but no start. Pulled off the cold start injector and put it in a cup, cranked the engine, no gas shooting out of valve. Found another valve at U-pull, installed it and did the cup test again, fuel was squirting out. Reinstalled valve, starts right up now no matter how cold.
Was a little tricky to figure out.
There’s nothing worse than an electrical failure in a circuit with a bad mechanical component. Just when you think you’re done, it’s back to troubleshooting based on a new set of conditions.
However, this does bring up a “was it the chicken or the egg” question-
Does an electrical circuit failure lead to a component failing from disuse, or does a component failure then burn up the control circuit?
Depending on the circuit and device, I can picture situations where both sequences occur.
One of my co-workers impressed me by (temporarily) getting around a bad compressor starter relay on his home refrigerator by replacing it with an incandescent light (he took 2 alligator plug wires and attached one side to the plug on a floor lamp and the other side to the socket where the starter relay would go. Kept the fridge going until he could get the replacement part. I have to add that he’s not in the appliance/refrigeration business (but is obviously very good at not just figuring out what the problem was but also characterising another device that might serve as a temporary replacement…today we liken that to the “McGyver” TV series in the ’80’s and impresses people like me to no end…since not only did he correctly diagnose the problem but was able to work around it without having the replacement part in hand, a useful skill also in the automotive area especially to keep your car going if you don’t have ready access to replacement parts.
My BIL’s ’84 Plymouth Reliant quit running one day just as he pulled into his drive (a great place for a car to quit!). He called me for help. After trying for at least an hour to get the thing started I had a hunch that it was a broken timing belt. We got the timing cover off to inspect and you guessed it – broken timing belt. Fortunately these were pretty easy to replace on k-cars.
Another starting problem, with the complete opposite symptom’s happened about 3 years ago with my other Jetta, an ’86 Jetta GL I’ve owned since 1991. The engine would start right up cold and run fine, but when warmed up was at first hard to restart, and as time went on impossible to hot start, let it cool about half an hour then it would start and run fine.
It had about 300k miles on it and still had the original fuel pump on it, and a family member I loaned it to had recently ran it out of gas completely, so I suspected the main fuel pump under the car was ruined by running without fuel to lubricate it when she ran out of gas. I looked at it and it was leaking a little bit, dripping slightly. This also explained the recent smell of gas I was noticing in the car. New fuel pump fixed the leak and the starting problem. Oddly enough cold starts require lower pressure than hot starts, and the pump must have been too worn to achieve full pressure.
I was once stumped by a VW. In the mid 80s a friend with a late 70s gas Rabbit called and asked if I had jumper cables. I drove to where she was parked.
I discovered that the car cranked over fine. She kept insisting that it would start with cables hooked up. I kept insisting that was an exercise in crazy. As a last resort I hooked up the cables, to quiet her down if for no other reason. Damned thing started immediately.
All I can figure is that some component needed some extra voltage to cause it to fire and start. I didn’t try to figure it out.
Did it have a L-Jet Bosch fuel injection system? A similar no-start problem fairly common problem on Alfa Spiders of that era. Cranks fine, but no joy. Horn beeps and lights work.
“One of the design parameters of the L-Jetronic system is that there must be 10 volts on the #10 pin connector at the ECU for the car to start. If there is less than 10 volts, the ECU shuts off. This requires a very good battery because the electrical load during starter cranking can cause the voltage to drop below 10 volts at the #10 pin. “
So you think the battery, if not great, is at least decent….but it’ll dip below threshold under cranking load.
I once owned a ’75 Volvo 164E with that L-Jetronic EFI and that issue you mentioned right here gave me nightmares. That damn car ate alternators and left me stranded SO many times… grrrrrrrrr… I still get pissed when I think about that steaming pile of crap car.
I swapped the distributer in my ’69 510 with an electronic ignition unit from a ’79 200sx. it had the separate module under the dash. At times it would have the exact same sym
ptoms as your friend’s Rabbit and same result with the jumper cables.
It turns out the ignition module needed at least 9v (I think) to generate a spark. Any less than that no joy!
A lot of early automotive computer systems used 9v for Vref and the processor. Problem was that in many cases of a marginal battery the starter would be able to keep cranking the engine despite the fact that the battery voltage was sagging to or below 9v due to the load. Now of course it is all 5v or 3.3v for some chips so you don’t get that situation where the starter is cranking but there isn’t enough voltage for the computer to run.
I swapped the distributer in my ’69 510 with an electronic ignition unit from a ’79 200sx. it had the separate module under the dash. At times it would have the exact same symptoms as your friend’s Rabbit and same result with the jumper cables.
It turns out the ignition module needed at least 9v (I think) to generate a spark. Any less than that no joy!
Wife was driving her dad’s ’97 Crown Vic for a few days (they had borrowed her Expedition). One day the Vic wouldn’t start. Cranked fine, just wouldn’t start. For some reason, I backed my Marquis out of the garage and attached jumper cables to the Vic- fired right up. Turns out there’s a failsafe in the ECM. If it detects low voltage, it shuts the injectors off to prevent damage.
I’ll bet the fuel pump relay was the component getting tired, and the extra current with the jumpers was enough to kick the relay on and start the fuel pump. Fuel pump relays often failed or got wonky, I still carry a jumper wire in the glove box for the fuse box just in case.
Ok, this brought back a memory! This will be a bit windy…..Back in 2005, I had a 1996 Maxima I bought new that showed a CEL one day. My mechanic diagnosed it to be a bad vehicle speed sensor….it wasn’t putting out whatever it was supposed to put out to the ECU. Changed it out, didn’t fix it. Changed it again, still got the CEL. At that time, New York didn’t care if the CEL was on at inspection time, so we “fixed” it with a piece of black electrical tape over the CEL.
Fast forward to 2008 where NYS decided a CEL was grounds for a failure at the annual inspection. My mechanic says Ok, now we gotta fix it. He determined that the speed sensor sent a signal to the ECU, which in turn sent something to the speedometer, which by the way was working perfectly. He arranged to borrow a proper ECU and installed it. NG. He had to return the borrowed ECU, so put the original back in. Next he borrowed a speedo and put that in. NG. He had to return that, so back in went the original.
I’m running around with a failed inspection, so had to do something. Just happened to be rooting around the internet when I came upon another 96 Maxima owner with the EXACT SAME PROBLEM! He did the same things I did, but, to make a long story short, he replaced BOTH the ECU and the speedo head AT THE SAME TIME. Fixed. I printed it out and took it to my guy. He did that and VOILA! Fixed. He theorized that the wiring between the ECU and the speedo for that circuit became damaged and fried whatever electronics was on both ends of the circuit.
I sold the car with 300k+ on it in 2011 with nary a problem.
I don’t have a story for a car but do for a jet. Keep in mind suck squeeze bang and blow is all you need to make a jet motor go. One could make the case a Navy fighter thirty years old qualifies as a flight line “classic”.
A reoccurring problem kept showing itself with a left variable exhaust nozzle on a GE 404 engine clamped to a F18 Hornet. At idle, instead of remaining open it would fluctuate slightly, not a huge concern, but we were getting feedback from pilots flying aggressive maneuvers. So we grabed our gear, powered up and viewed the numbers, then it happened, wild fluctuations indicated and physically confirmed. Standard troubleshooting, bleeding the oil system, checking actuators and loose connections. No help. Dug deeper checking sensors, testing electronic control unit, removing components checking broken shafts…everything the manual said to do. After eight hours and all manner of speculation I decided to crawl into the exhaust and eyeball the afterburner combustible can. And there it was, a hole about the size of your fist tucked forward, barely visible between the afterburner can and the housing. Suddenly the symtoms made sense. With throttle set at idle, the hole allowed exhaust pressure to drop signaling the nozzle to close thus increasing pressure relaxing the nozzle position. So the system was working as specified when a section of metal was missing. Had to remove and replace the engine but got depot level maintenance a head start on the repair.
Wrote a report for a technical publication change adding internal exhaust inspection before troubleshooting components as learned sometimes motors work as they’re suppose to.
One evening the dashboard light up like a Xmas tree as i attempted to start my ‘83 Cutlass Supreme. Then the car would not start at all. A friend gave me a jump, the car ran fine and I got home.
Next morning, no juice from the battery. Being a 231 V6; I had enough room to follow the cable from the battery to the starter. Sure enough, the cable had chafed and shorted out against the fire wall. After wrapping the exposed part with electrical tape and replacing the battery, had no electrical issues for theremaining 5 year I owned the car ?
I became a wizard at identifying no-starts because of misaligned neutral safety switch. Hold down the brake pedal, turn the key, gently press the gearshift, thar she blows!
The V8 in my ‘72 Monte Carlo developed a regular miss in spite of having had a recent ignition tuneup. Somewhere, I heard of the “dollar bill test” but was rather skeptical.
WHT, I decided. Nothing to lose by trying. Held a dollar bill next to the tailpipe while it was idling and sure enough, it would get sucked onto the exhaust every so many exhaust pulses.
Voila! Exhaust valve trouble, confirmed by a failed compression test on one of the right-hand cylinders. Subsequent teardown revealed a cracked exhaust valve on the suspect cylinder.
Gus Wilson would be proud.
Thank you for the big smile, Ed. Mr. Wilson and his “Model Garage” snapped right back into memory—the stories, and then the hints:
This goes back to the tale of the 710s. My brother had lost his first 710 to a 10 day mandatory safety ticket and a year or so had gone by since. I answered an ad for a ’75 710 and a large supply of parts. I went to check it out and negotiated a deal based on the present owner had changed the head gasket and can’t seem to get it to run right. I drove it up and down the farm driveway and knew I could have it running beautifully in 15 minutes or less. I got it cheap and he got the full ask. After loading up my truck three times to haul away the stash of parts, literally everything you could possibly need for the next 20 or so years, the only thing remaining was to go and get the car.
I didn’t really need the car but the parts haul was enormous. My mother needed a car but didn’t want this one because of the standard transmission so I suggested we trade it for my brother’s car which was an automatic. After a bit of negotiating another deal was put into play and arrangements were made to get the Datsun.
Now I didn’t tell my brother what was wrong with the car because he likes to talk and for sure he would spill it out to the guy when we got there. I only explained to him that it hasn’t got much above idle so feather the clutch and go real easy on the gas pedal and don’t pull out in front of anyone. It was all farm roads and we had plenty of time.
We leave the farm with me following in my truck and not too far down the road I see my brother making strange gestures with his arms out the window. He pulls over and comes to my window literally screaming profanities at me about what a pile of crap this is, the deal’s off, etc. Now I really don’t want to tell him what’s wrong. I tell him calmly that I have a tow rope for when we get into town if that will make you feel better. Didn’t use it though because when he wanted to I just left him behind. Yell at me like that and you’re on your own.
We get home and in the driveway he continues to moan and complain. I quietly go to work. I set the motor to #1 tdc remove the valve cover and wedge the timing chain. Only then did I break my silence. The guy I bought the car from changed the head gasket. It’s at top dead centre now so the tip of the #1 intake cam lobe should point at the head of the bolt on the #2 cam tower. Notice that it’s not. He put the timing chain on one tooth retarded and that is why it’s not running right. Five minutes later with everything put right and torqued down I was off tearing around the neighbourhood. No apologies at all and hindsight being 20/20 I should have kept it for myself. It had 18,000 actual miles on it at the time.
It wasn’t a brilliant diagnosis but I did get to stick it to Mr. Knowitall and the seller felt good about letting go of it.
For a while, my car was experiencing a mysterious driveline clank that initially I thought might be the clutch throwout bearing. I eventually realized it might be one of the engine mounts, of which my (FWD) car has three. After looking at how they were configured, I was reasonably sure which one it probably was — the clank came whenever there was lateral displacement toward or away from that side. Since I don’t have tools or a work space, I took it to the mechanic, who couldn’t see anything externally wrong with any of the mounts. I finally decided to gamble — it was a lot of money, but having new engine/transaxle mounts is not a bad thing regardless — and had them changed out.
When I went to pick up the car, the mechanic showed me the old center mount, the one I had suspected was the culprit. The outside looked pretty much fine, but when he picked it up, it made the exact clank I’d been hearing for months. Part of the inside structure of the mount had cracked, leaving the outer shell basically holding it together.
I’ve had a few proud moments figuring out what’s going on with a car but one I’ll never forget was one that made me look like a hero and I didn’t even do anything! Back in high school I had a 3 year crush on a girl that was way out of my league, she was a debutante, varsity cheerleader, and came from old money. But she was different from most other girls in that class of folks because she was still friends with guys like me, it was no secret that I was in love with her, and everyone knew. Anyway, she had a 1994 Ford Bronco (that’s what initially drew me to her!) and this was in 1997, so it was very nice and didn’t have many miles. One Friday night I got a page from her (remember beepers?) I called her back immediately of course, and she said she was at her friends house and they were trying to leave but the Bronco wouldn’t start. She also told me who’s house she was at and that there was a LOT of other girls there too. She was at one of the other cheerleaders houses, and basically the entire varsity cheerleading squad was there! I was so incredibly nervous and excited that I couldn’t even think straight! I just kept telling myself over and over again as I drove over there, “you better be able to fix this thing!” When I got there I pulled up to a scene of roughly 15 of the hottest, most popular girls in my school all hanging around outside and not one other guy in sight except me. I have no idea if I played it cool or not, I’m sure I probably didn’t, but I tried. After talking with her for a minute or two I made my way to the Bronco, heart pounding, hands sweating. All I had been told was that it would turn over but not start. I didn’t even try starting it at first, probably cause I was a mess and not thinking clearly, but I popped the hood, tapped on the MAF sensor with a screw driver, and then tried to crank it. The thing fired right up and ran just as good as new. I was shocked, and overjoyed and remember telling myself to not let my surprise show! The girls were very excited and were all telling me how awesome I was and all that good stuff. And my crush gave me a big hug and held my hand (I know, sounds cheesy now, but it meant the world to me back then). And as I was walking back to my truck and they were all getting into their cars, she called to me and told me to page her on Saturday so we could hang out. Now we had hung out a lot before, but it was just the fact that all these other girls heard her say that, that made me feel like such a badass. So long story short, I have no idea what I did to get the thing started! Was there really something going on with the MAF sensor? Who knows, but I looked and felt like a hero that night and I can honestly say that that was one of the best nights of my life. What can I say, I was 17.
Just one? If you make me pick just one, it’s probably this: Around 1991 or so, the 302 in my folks’ piece-of-ѕhit, very-unwisely-bought (used in ’87) ’80 Stinkoln Clown Car started making a rattly noise. They very unwisely had it towed (again) to the stealership, whose service department I proceeded to call and—both sure of myself and full of myself, despite a complete lack of evidence—I told them it was probably the oil pump. They waited most of the day and then, sure ’nuff, turned around and called my folks and said it was the oil pump necessitating a rebuilt engine. Finally after four or five years of nothing but constant breakdowns and failures in that poorly-engineered, sloppily-built, pathetic excuse for a car, they decided enough was enough and turned it out to pasture by donating it to a high school auto shop. I call that my best diagnosis because it probably saved the most money; if the stealership had been left to their own devices, they’d’ve probably diagnosed (or pretended to diagnose) whatever was really causing the rattle and my folks might have agreed to the repair.
But there are much more interesting diagnoses in my history. The Wayback Machine first takes us back to in front of my folks’ house when I was eight or nine. Babysitter’s much-neglected ’63 Volvo Amazon/122 wagon refused to start for her. Plenty cranking (in the slow manner of a worn Bosch 12v direct-drive starter fed by a marginal battery through iffy cables) but no fire. I had very recently become interested in engines, starting with the one on my folks’ late ’70s Craftsman lawnmower, and had persuaded my dad to take it in for its first tune-up, some six years after it was built. It had come back running much better, and one visible change had been the new replacement air filter.
I just barely didn’t need tiptoes to see the pancake air filters on the twin SU carbs in the Volvo were super crusty, the same way the old one on dad’s lawnmower had been before the tune-up. No way I could reach to do anything about it myself; I told my decidedly un-car-mechanical father to remove them. He was “reluctant to fool around with parts of the engine”, but I was persistent and the babysitter really did have to get home, so he compromised by removing just one of the air cleaners. Whereupon the longsuffering B18 chugged to life (more or less) at the turn of the key. I’m quite certain the air filter was never reinstalled or replaced, and it’s a good bet the carb dashpots were empty of oil, the points were badly burnt, the plugs were worn and dirty, etc.
Or the time when I was in high school and the Activities and Extracurriculars Office secretary’s Jeep Wagoneer refused to start. A dead battery, as it seemed. A few of the other yearbook editors and I happened upon the scene. Curt, who had a noxious superiority complex, set about using jumper cables (“Stand back, Dan, I’ve got it under control”). Except not, ’cause it didn’t work; the Jeep remained dead. Scott, who had excessive money, didn’t want to sully his precious BMW 7er to the dread diseases transmissible by contact with electrical systems of, y’know, American cars, so he mumbled some lame excuse. Okeh, now it was my turn; I’d been watching what was (and wasn’t) going on in the engine compartment. I commandeered two Philips head screwdrivers from James (“Stand back, Curt, I’ve got it under control, Curt”). Jammed one screwdriver between each battery terminal post and its cable clamp. The underhood light suddenly got bright, and I knew I was onto pay dirt (er, pay corrosion). “OK, try it now, Mrs. D.” Curt and Scott backed up in a hurry, certain I was about to get broiled or electrocuted or something. Mrs. D keyed the engine, which started immediately. Ching!
I parked my Dodge Spirit R/T in the driveway one day after a trip to the grocery. Mother went to borrow it, but came back in the house demanding to know what I’d done to the car, which would not start. What? It was running fine not five minutes ago. I went outside and…sure enough, no start. No crank. No nothing, in fact; the car’s powertrain seemed electrically dead. Had headlamps and horn, had dome light, but that’s about it. And some weird code (“F-01” or somesuch) on the trip computer display. Umwhut? Think. Let’s think. It’s probably not the ECU, because that can be dead and the engine will at least crank. It’s not the battery, because we’ve still got headlamps and horn. Ummmmm…fusible link! Sure enough, it’s blown all to hell. Alright, I don’t have any fuselink wire to effect an official repair, but I do have an ATO fuseholder; I can and do easily install that in place of the burnt fuselink.
But something caused that fuselink to blow, and sure ’nuff, soon as I turn the ignition key to “on”, the fuse in the holder goes POP!. Not just dead, but very dead.
So what’s the trouble? Quickly enough I find it: there’s a little plastic Christmas-tree type retainer that snaps into a hole in the air cleaner heat shield (to prevent the very hot turbocharger melting the airbox) behind the rear cam cover. This retainer is attached to a plastic ring, through which runs the 4-wire cable to the O2 sensor. This retainer lost its grip, the cable fell down on the hot turbo housing after I shut off the engine once home from the grocery, thoroughly cooked the insulation off the cable and its individual wires, and as soon as the key was turned to “on” and current was sent to those wires, well, pop goes the fuselink and its subsequent ATO fuse.
I’d recently salvaged a bunch of premium-quality, tinned-strand, high-temperature wire (“GE Flamenol”) out of the 1966 GE wall oven my folks had recently replaced; that oughtta do nicely. I cut out the barbecued wires, made new ones to bridge the gap, might have enclosed them in some corrugated wire loom if I had any (I don’t recall) and ran them over the top of the heat shield rather than under the bottom. With a new ATO fuse in the holder, the car started right up. That was not a correct fix; every now and then the fuse would blow under a transient load peak and kill the engine dead, but I never bothered to put in an appropriately slow-acting kind of circuit protection; eventually I sold the car.
In my University of Michigan days, I was able to get the Solar Car Team leader’s own Dodge Spirit (a much more pedestrian 2.5 TBI model) back on the road with a paperclip late one night—I’d got a “Halp!” phone call from either him or one of the other teammates who knew I knew stuff about Mopars. I drove out to the Engineering campus with my toolbox. His car was totally dead, wouldn’t crank. A jump start would crank and start it, but the Check Engine light remained lit and the engine would die as soon as the cables were unhooked. Triple keyflick to pull the codes: 12, 41, 55, that is start of codes, alternator field circuit open or shorted, end of codes. A close look at the alternator showed the nut had come off one of the two field studs. The other nut on the other stud was holding the twin-tab terminal firmly in place, dead-centred such that the nutless terminal tab was making no contact with its stud. No chance of the correct nut at whatever-thirty at night, so I fashioned a retainer clip from a paperclip, whereupon his car started (with a jump) and stayed running after cables removed.
I’ve done some pretty decent sight-unseen Dx’ing, too. 12 years ago on a listserv for RWD Volvos, a member posted that his ’77 240 was behaving very strangely: the fuel pump was loudly screaming, and he—thinking maybe a vacuum had developed in the fuel tank—loosened the cap. Or started to, anyhow; at 1/4 turn it blew off the car with great force (he couldn’t contain it with his hand), gasoline spewed out of the filler, and the car stalled. It would crank all day, but would not start with the cap off. Install the cap, car starts and pump screams, massive pressure builds up behind the cap.
So, a wacky set of symptoms: something is actively pressurising the fuel tank, which should never be the case. What’s more, the car won’t run without this abnormal, grossly excessive fuel tank pressure. So where’s this pressure coming from? There’s really got to be air involved,
getting pumped via some route into the tank. This air could come from
outside the tank, or it could come from within the tank, above the level
of liquid fuel. But why won’t the engine run without the abnormal fuel tank pressure? My guess: Because the large reduction in fuel pressure and volume at the injectors due to the air in the system will not let it. Install the gas cap, let pressure build in the tank, and that tank pressure adds to the pressure generated by the pumps, increasing absolute line pressure and reducing the size of the air bubbles (same as a radiator pressure cap does), to the point where there’s sufficient fuel pressure and volume at the injectors to run the engine.
Grand. So where’s the air coming from? Gotta be coming from the inlet side of the pump. I tell the owner to go look at his rear-of-the-car fuel lines carefully. His report comes back: Yep, some PO had replaced a section of the tank-to-main-pump hose, crudely sorta-clamping the patch section in place. One or both of those clamp joints had grown sloppy enough to admit air, which aerated the fuel going into the pump (explaining the pump screaming and the no-run-without-tank-pressure). The air was then shunted into the tank via the fuel pressure regulator (explaining the pressure). With a proper repair using appropriate fuel injection hose, the air leak was eliminated and everything went normal.
If we eliminate the Lincoln I started this rambling reminiscence with, I guess that’s probably my best automotive Dx I can bring to mind at the moment.
I’m certainly only in the second category you describe, JP Cavanaugh. If wishing were doing, etc., and I lack the courage to dive in. But nowadays, I love the ‘net and Youtube. There’s always something from someone (often beardy and a bit lonely-looking) on the problem that bedevils you. And full understanding is not necessary. I don’t need to know what a Fuzzgurgler 3.0 is, I just have to look at the pictures and see the burnt-out and non-burnt versions, and therefore whether I remove it or not. Literally thousands saved in last number of years by these methods – but they’re kind-of cheating on the question you ask.
So my best pre-internet diagnosis resulted in getting a garden hose and sticking it in the carb of my correctly sparked but endlessly-pinging Ford six, because a dim bulb flickered in memory that you could steam-blast carbon away. Well, the very worn motor coughed and burped and spat a bit, but didn’t stall. And I’ll be blowed if it didn’t work. I’ve no idea of the science behind this, seems iffy to me, but I could not argue with what resulted. It stopped pinging, and it stopped running-on at shut off. Job, as they say, done.
And thus one non-mechanic marched confidently into vastly less successful diagnoses. Which pride determines he is not about to share.
the a/c unit on my Honda. One day no a/c and then I noticed a wire pulled off the compressor. Simply plugged it back in and then had a/c
The one I remember the most was in 1967 when I was in college and had a summer job at the Gulf Oil jobber in a nearby town. The company had a fuel truck that made deliveries to farmers and others who had their own gas pumps. It was a 1951 Ford that they had swapped a 390 into. One day the boss was gone and the driver brought it back from a run and was complaining about an intermittent miss in the engine. He said it had been happening a lot and the Ford dealer could not find it. I offered to help him find the problem even though I had limited skills at that time. After pulling it into the warehouse we let it run a while and you could hear the miss. We couldn’t see anything wrong, so for some reason that I don’t remember I crawled underneath the front end and looked at the bottom of the engine. It didn’t take long for me to spot the plug wire arcing against the exhaust manifold. We did a temporary fix with electrician’s tape and it ran like a charm. Right after that the boss came back and when the driver told him that I diagnosed and fixed it he was amazed. It really surprised him that I actually fixed the problem. He then got back in his pickup and drove down to the Ford dealer and chewed out the service manager. He told them that he drove a lot of Ford products and had brought the truck in several times with no results. If a goofy kid could fix it, then maybe he should be looking at a different dealer.
Cars, jets, radios…Back in the 1980s, when I first started repairing guitars, there was a nice older hollowbody for sale cheap in the classifieds. I called and the owner said it’s cheap because he could not get it to stay in tune, no matter what he did. I came to check it out and he proceeded to pull out an electronic tuner and demonstrate how the guitar was absolutely useless and how he’s sorry if I made the trip for nothing. I bought it anyway. Then I took it home and put a floating bridge on it. It was perfect, other than the missing bridge. Back in the 1980s, the age of fancy whammy bar bridges, not everyone knew how a floating bridge worked on an old hollowbody. I was a dumb kid just starting out, but that episode made me feel really cocky for a while – until a bit more experience taught me how much I didn’t know.
In 1989 I had a 1975 Volvo 164E break down in the middle of nowhere. I called my father and explained the symptoms. He deduced fuel pump. In my Haines Volvo book it clearly read to hit the fuel pump with a blunt object.
It worked.
I watched my neighbour for the um-teenth time fiddling around under the hood of his car so I wandered over. “What do you think?” he asked. I removed the radiator cap, handed it to him and said “This part is good, you need to change everything else.” We laughed about that for years.
My mother’s friend one time said “I can’t understand it. I’m filling the tank two or three times a week now and I’m not doing anything different. Everyone has had a look at it and can’t figure out why” I said “Start it up let me have a look.” I opened the hood looked on one side and then the other and said. “You need a new fuel pump.” There was a pin hole in the pump body and with the engine running a tiny stream of gas was spraying onto the exhaust manifold and so far safely evaporating.
Experience being the best teacher, I knew to check the points gap *first* on the ’62 VW Beetle sunroof I had just purchased, which indeed were closed up. Five minutes later, I had a live Beetle on my hands.
The first time this happened (from whence experience came) was when I bought my non-running ’71 VW Bus. It took several weekends slowly working through my brand-new Idiot Book until I got to the bit where you set the points. Voila!
As I frequently told my sons, “Wisdom is the consolation prize you get for screwing up.”
Our elder son, after some googling, successfully pulled the dashboard out of our old ’98 Grand Caravan, resoldered all the connections and put it all back together again, which fixed all the flakey electrical issues the van had developed after over 200K miles.
Hmmm….I don’t remember WHICH Honda Accord now, but one morning one of them wouldn’t start. Cranked and cranked and cranked. Seemed as if it was getting gas.
I have no idea what made me think of this (except we had had a big rain storm the night before, so i was thinking wet, I guess), but I took the other car to the auto parts store and came back with a spray can of wire dryer. I sprayed the plug wires and distributor cap with the stuff, and waited for about 15 minutes.
It started right up.
The company I worked for way back in the 1990’s had a strange way of handing out titles. If you had an engineering degree and worked in a test lab, you were a “test engineer.” If you had a physics degree and did the same job, you were a “lab analyst” and made ten to fifteen percent less money. Not having that degree also slowed your advancement up the corporate ladder unless you went into sales.
I tested filters in water-based environments, the lab next door did the same with hydraulic systems. The guys in both labs were recruited on their wrenching ability, and the manager of the hydraulic lab was known to do oil changes on his car in the parking lot.
One day, I’m returning from lunch, pulling into that same parking lot when I see a bunch of these so-called engineers crowded around an ’88 V-6 T-Bird with the hood up. The engine cranked, no start. Then it would run for a second and die out. Lots of possibilities, but I was thinking fuel pump and that’s what I told those guys. They, of course, asked how I could tell.
I pointed to the little thing that looked like a tire valve on the fuel rail. I said just turn the ignition on (no need to crank, just get the fuel pump going) and if no fuel comes out of that when you push the valve in, or if you don’t want to get your hands dirty, nothing comes up on a tire gauge, you have no fuel going to the engine.
Remember this company made filters. Fluid systems were what they were all about. What’s a fuel system? Turns out I was right.
I’m in the simple repairs only camp, but probably the most effective diagnoses I made were during ownership of my 1987 Cadillac Brougham. It had the OBD I system, so you could stick a paper clip in the scan ports, and the check engine light would flash the code, which you could then look up. So Id show up at the mechanic with a replacement for whatever sensor was broken and the diagnosis.
I developed a similar skillset on the EECIV system in this same Mercury. Only its preferred method of communication was through an analog dwelltach. A manual provided the translation key for the sequence of swings of the needle on the meter.
“Back in the day”, I was pretty good at mechanical diagnosis, but a bit weaker on accessories.
I was trying to diagnose an inoperative factory radio in a ’55 DeSoto. Power to the radio but no sound. Figuring a bad tube, I pulled the unit, took the tubes out and took them to Marv, an old guy I knew who still had a tube tester. Marv used to fix old TV sets. Today, his skills are about as obsolete as mine.
Anyway, Marv checked the tubes and told me they were all OK. Stumped, I asked Marv if he had any ideas. His 1st question was whether I heard any humming when the radio was turned on. When I told him no, he said the radio probably had a bad vibrator.
Not being familiar with tube radios, I thought Marv was pulling my leg. I told him I wasn’t interested in the radio’s sex life, I just wanted to see if it could be fixed. Marv told me I wasn’t kidding. He said to put the tubes back in the radio and look for something on the radio chassis that was about the size of a vacuum tube, but looked like a metal can. If I found it, I should bring it to him.
Back at the DeSoto, I found the vibrator and realized it could be easily pulled from underneath with the radio still in the car. I reinstalled the tubes and radio and drove the whole car over to Marv’s taking only the vibrator into his shop.
Marv shook it a little, listened, then suddenly pounded the thing against his workbench – real hard. So hard he dented it. I was shocked, but Marv didn’t seemed concerned. He handed me the now slightly dented vibrator and told me to try it.
I was skeptical as I pushed it back into the socket. However, when I turned the key, I heard the radio start humming. A minute later, the rich sound of a tube radio on an AM station came through.
I was amazed. I went back inside and asked Marv what manner of sorcery he had worked on the vibrator. He explained a vibrator provided the oscillating higher voltage required by old tube radios. With age lack of use, mechanical contacts in vibrators could stick. Hitting them could unstick the contacts.
Vibrators were obsolete even when I worked on cars having been replaced by transistors in the early 60s. However, should you ever run into a car with a inoperative factory radio from the 40s or 50s, you’ll now know an important trouble shooting step.
You can also show off this trivial knowledge the next time your watching an old movie and an actor hits the side of a TV or radio to make it play. You’ll know it wasn’t ignorance, but a genuine understanding of how to fix things.
One time when my computer monitor wasn’t working, the IT guy I called happened to see me hit the side of the monitor in frustration. Later I heard the story had became a legend in the company IT department. To this day, whenever I have to call our IT help line, one of the 1st questions is whether I had tried hitting it. I always hear laughter in the background too.
Oh for the days when a man could fix something just by hitting it!
Old Dodge van, carbd 318, driver said it sputtered on the highway and then the OIL light came on. I bet lunch I knew the problem sight unseen, and I won: fuel pump, diaphragm failed.
“until a bit more experience taught me how much I didn’t know.” .
1,000 times this .
A work mate wanted a Datsun PL620 pickup truck and another one had a mustard yellow 1971 one with a green driver’s door, I asked him since he’d stopped driving it to work if maybe it was for sale ? .
‘Yes, $250 but the engine blew up near my house ‘ .
? Tossed a rod, seized up, burned a valve or what ? .
‘no, I pulled up to the stop sign at four corners on the Pearblossom Highway next to the swap meet and it died, cranks but won’t fire’ .
O.K., I said, we’ll be out to fetch it this Saturday, paid the $250 (current tags !), towed it out of view and took the carby apart, removed a bit of crud from the primary main jet and my buddy who’d wanted it, drove it for close to ten years needing only a clutch disc and of course a major tune up .
My Son bought it from him and thrashed a few years more, sold it on to a Nephew who was a typical pretend angry Hispanic, he got some use out of it before he killed it via neglect .
It was, IMO, a nice little trucklet, it had an early 240Z five speed tranny with the reverse shift pattern . turns out most all older Datsun trannies swap bolt for bolt .
I liked it so much I eventually bought a 1978 Datsun PL620 long bed pickup, that wasn’t a good one sad to say .
I’m sure the _mis_ diagnosis stories would be me educational and embarrassing to boot .
-Nate