Cars, etc.

[Bob Zumbrunnen]

Think I already mentioned that my SHO threw the timing belt on the test-drive after I'd replaced the plug wires.

Since the guy who bought it told me the timing belt had been replaced just a dozen or so miles before I went to look at it (along with a motor-mount), I was suspicious that I'd caused this one myself.

I'm reluctant to use blue silicone sealant and used to always say "Blue Goo: The sign of the a-hole mechanic.". Especially on motorcycle engines where a loose blob of it can easily clog an oil passage. I've seen motorcycle camshafts seized because of this kind of clogging.

But the rubber valve-cover gaskets were in good shape and though the seals around the spark plug holes were hardened, so not trustworthy for sealing, I didn't want to spend $90 on replacement gaskets. So I conservatively used blue goo on the valve-cover gaskets and more aggressively on the spark plug seals.

Anyway, finally got the new timing belt and replacement accessory belts yesterday and started tearing it down.

I suddenly remembered again that when I was getting the new tires put on the car, I inspected it from underneath and noticed that the accessory drive belts were old and cracking. Thought it odd that they wouldn't replace them since they had to come off for a timing belt change.

Well, I got my answer last night.

The timing belt had several tens of thousands of miles on it. Whole thing showing cords and the frayed material that'd been coming off of it over the years had accumulated heavily inside the timing cover. It's not the original belt (which couldn't have lasted 140k miles).

Both sets of camshafts turned freely, but since I've seen things seize then move freely again after cooling down, I went ahead and pulled the caps. Mirror surfaces everywhere. The timing of the camshaft breakage was mostly coincidental.

I doubt the old belt has been causing the problems, though. It could let the cams get out of time some without jumping teeth, but doubt it could do it enough to always feel like I've lost half the cylinders.

It's likely that the misfiring the car was doing on the test drive at high revs caused it to try to open valves against compression or combustion, resulting in just enough camshaft resistance to break the worn-out belt.

So, the guy who sold me the car was lying through his teeth. Why am I not surprised? Especially since he sells used cars (mostly restored old Caddies and Mercs) from his home for a living.

Heck, I knew to beware when he bragged about the coldness of the AC when it was about 20 degrees outside. But I insisted on an 89 SHO with a 5-speed and the cloth seats were the kicker that talked me into it.

I've been reading around the 'net quite a bit and a number of folks say they just leave the timing covers off of this car. I'm not sure about that. The crankshaft position sensor looks awfully vulnerable and I live on gravel roads. But about 90% of the time I spent getting the belt off was spent getting the (3) covers off. And I expect to be putting aftermarket camshafts on it before too long and adjustable sprockets, which means I'll want to check and fine-tune the cam timing now and then. Perhaps I can figure out a way to protect the CPS while still leaving the covers off.

I'd be about ready to start putting the car together, but I'm removing all of the most easily-removed and visible parts and cleaning them. And checking for any oil leaks. Kinda hard to tell since the valve covers were leaking so much before.

And I'll probably go ahead and buy the new gaskets. When I was test-driving it, it acted like the front valve cover was still leaking, right onto the exhaust.

So, the fun continues. I'm going to give the Mustang its much-needed brake job this coming week, slap street tires on it, crank out some of the negative camber, and get it inspected and licensed for the first time in several years. Seems I can't trust the Taurus too much and I really hate driving my truck (but have to keep it because of the trailers), so I'll drive both the SHO and the 'Stang.

I love working on cars when I want to, like for performance improvements. I hate working on them when I have to, though.