I have had two independent people tell me that with oil leakage around my cam cover, I could probably use a valve adjustment on my >100K mile '87. This sounds very reasonable to me (if cam gasket leaks, no one has replaced it over the life of the car / adjusted anything)
So, I am leading myself down the slippery slope - valve job not too expensive, but I could go through whole engine, do a complete rebuild, ya know, “while I’m in there” or have an entire new engine vs rebuilt engine installed for not too too much more…
I have no clue where wasting time/money versus being cautious lies with an older car driven hard. Any advice is appreciated!
A valve adjustment and a complete rebuild are decimal places different in price. A leaky valve cover gasket and a valve adjustment are fairly standard service/maintenance tasks.
Replacing a motor is a completely different endeavor. “While you’re in there” is a dangerous term to throw around. Only Racer X Jim Robinson has actually built a complete brand new E30 from individual new parts, and while it sounds attractive and makes Steve D jealous, it starts to become an argument of “Diminishing Returns” instead of “While I’m in there.”
While you’re replacing the engine, also replace the clutch. And while you’re replacing the clutch… And… and… clutch packs in the diff… and… paint… and stickers… and stickered tires… and…
I’d do a quick compression and leak down check before I started tearing things apart. If the numbers are good, just deal with some of the easy stuff. Simple gaskets and valve adjustment. Shouldn’t cost too much and can easily be done at home. If the numbers are bad, look at a few of Ranger’s posts and see what you feel like doing…
Compression and leakdown tests are very helpful if you are trying to understand a problem. But if you know of no problem, then the tests are less useful. In that second scenario the tests might help convince you that you have a problem that maybe you really don’t have.
I have a DIY for compression and leakdown tests, and another for valve adjustments on my website. The best source for figuring out how to do this sort of thing is a relative novice like me who recently (pretty much) figured them out.
Folks that have been doing valve adjustments and compression/leakdown tests for years aren’t as much help because they do it with their brain on automatic. They’ve forgotten the million ways a novice can screw things up or otherwise confuse the crap out of themselves.
Here’s what you should do. Adjust your valves and then go take your car to a dyno that has seen other SpecE30’s. Don’t screw around with other tests, just go see if it has power or not. Alternately, go spend some time on a track with other SpecE30’s. If your engine does ok, then go home with a smile on your face. Because as god is my witness if you tear apart your motor because you just “think” that maybe it’s down on power, without really knowing for sure, I will hunt you down and… Only salted earth will remain.
