In anticipation of a new COAL subject coming soon, I plan to update my fleet adventures of the past year or so. Given the propensity for my mind to wander, we’ll see how it goes.
In June, my wife and I faced the saddest day in the life of a pet owner when we had to put down our beloved 17-year-old tuxedo cat, Biggie. Biggie had been losing weight for years, but he never disclosed to us that he was in pain until the very end, when it was clear that he was having trouble breathing. A trip to the veterinarian confirmed the worst, and although it wasn’t really unexpected (his weight loss was an obvious sign he was ill), it was not a happy day. While big old Buicks are not analogous to cats in terms of being light on their feet, they can nonetheless be suffering from any number of torments while showing few, but obvious in retrospect, signs of distress.
Last winter, I wrote about my using a system from Lock-n-Stitch in California to repair an external block crack that had long been seeping antifreeze into the oil of my Buick’s straight eight. With the benefit of hindsight, I can say there were at least two fairly obvious pieces of evidence that there was a crack:
1. a “snotty” oil breather that I wrongly attributed to a 160-degree thermostat
2. small specks and swirls of metal in the oil filter housing that appeared at roughly the same time, which were troubling but seemingly unrelated (they still might be, actually)
Needless to say, I continued driving along for roughly 10 years, and it wasn’t until I was tracking down an oil leak that I discovered a big mess. Follow the link above for the gory details.
It may seem callous to not stop everything and tear an engine apart when you see ANY metal in the oil filter, and many “car guys” would certainly berate me on the internet (yet ironically, here I am bringing it on myself rather than hiding in my shame). But over those 10 years, the oil pressure never faltered (at all) and no strange noises ever gave me any indication that I should be seriously concerned with the health of the engine. My 28 years of driving old cars have taught me when I need to take immediate action and when I can let things ride for a while, or so I thought. After getting the engine running again this spring, I discovered that the draft tube was plugged with a sizeable glob of oil/moisture sludge that I will not share with my readers because it was disgusting. The plugged draft tube, by the way, was the cause of the oil leak I was searching for when I found the crack – there was insufficient crankcase ventilation. Somehow, and this is the theme here, the car managed to run quite well for all those years.
Regarding the metal in the filter: it was and is a little baffling. First, it was magnetic, so it was not bearing material. I had a couple theories and I ran a couple tests. My borescope showed some vertical striations on the cylinder walls that were indicative of mild piston skirt scuffing, so I figured it was possible that the metal came from the cylinder walls. Then, I checked camshaft lift with a dial indicator to ensure that the camshaft wasn’t eating itself alive (it wasn’t). When the engine was partially disassembled last winter, I removed the lifters and examined the heels, and they were like new. There was no evidence of excessive wear on the rocker arm shaft or valve stem tips.
In reality, chances are good that the iron emanated from the crack in the block and the seeping antifreeze introduced it into the oiling system, especially considering that the timing of the two pieces of evidence roughly coincided in my maintenance notes.
On the other hand, I recently changed the oil for the first time since the crack repair and once again found metal in the filter housing (not in the pan, I’ve never found any evidence that the oil in the pan itself had metal in it), but it’s possible that residue from earlier contamination is still littering the oil galleries. Time will tell, and I hope the news is good.
If the intention of this discussion is to rationalize my mistakes, here’s another. Over the years, the idle became a little rougher. It was never rough; after all, it is a Buick straight eight, but I ran a compression test anyway and found the cylinders somewhat uneven. The end cylinders had 130+ pounds of cranking compression, while the center six only showed 110-115. I try to think like a corner mechanic from the old days, just keeping my cars on the road for as long as I can before I rebuild something. Therefore, I retorqued the cylinder head to ensure it was properly tightened, which almost certainly exacerbated the crack that lay a few inches below the deck of the block. Oops.
Upon disassembly, I examined the head gasket, because that’s what you do when you remove a cylinder head. Dynaflow cars used a steel shim gasket to raise the compression ratio by a few tenths, and there was an indication that the center cylinders may have been sharing a little combustion. I asked my machinist to touch up the valves while the head was off and he confirmed that not all looked right in the world of straight-eight head gaskets. Both the head and the surface of the block were perfectly flat, so this was another puzzler. My theory is that steel shim head gaskets sometimes need retorquing after a few heat/cool cycles; I didn’t build this engine and failed to do that when it was fresh, and the engine builder didn’t mention that I should at the time. To be fair, the head bolts were not noticeably below specifications when I loosened them one at a time to retorque the head.
Rather than using another steel shim head gasket, I decided to surrender the extra “five” horsepower gained by the slightly higher compression ratio and use a Best Gasket “Graph-Tite” head gasket designed for the synchromesh-equipped 263. It is about 30 thousandths of an inch thicker when compressed, which may give me a little extra security.
Regardless of whether it was the valve job or the head gasket, the cylinders now pump an even 123-126 pounds of compression, and the engine idles a little more smoothly than it did before. Here is a video of my first start after reassembling the engine.
Last weekend, I got the Buick cleaned up and ready to put away for the winter. Although it’s still very nice here in Michigan, winter has a way of catching car owners unawares, and I have a fairly sizable fleet to winterize. With that being said, I typically drive the Special the fewest miles every year of all my cars. It’s my favorite, but it’s not really the best option when my fellow motorists are driving 85 miles per hour past speed traps and not being pulled over. After 820 miles this year, there is no evidence of a coolant leak, although there is perhaps a little more blowby than I would like for an engine with under 20,000 miles on it. Oil is leaking from a few spots that indicate crankcase pressure, but I also see these leaks on other Buick straight eights at shows, so that might just be what they do when they get a few miles on them. Given the raging turmoil the engine has endured over the last 10 years, however, I can forgive it for that transgression. I hope it forgives me for ignoring its distress signals for so long.
It’s been a bit of a nerve-wracking year, with the loss of our beloved feline friend and my anxiety about the Buick’s crack repair and the embarrassment as an amateur mechanic that comes from not doing something sooner. On the other hand, life’s joys would not be as distinct without a little disquietude. And the burble of a Buick straight eight is most manifestly one of life’s joys, even if one’s not always heeding the warning signs that something is amiss.
P.S. We love you, Biggie!