Long-time lurker, first post:
I have an '88 GL 5 speed D/R 4WD wagon that my family bought new. I have maintained it pretty much by the book since new and it has 213K mostly long distance highway miles. We did have some hot-running problems with it for several thousand miles despite a radiator recore some time back, but a new 2 row radiator fixed that last summer, thanks to USMB's suggestion. The car's been pretty trouble-free other than that up 'til recently.
The first issue - I've been losing coolant lately without any noticeable leaks, and just this week the exhaust started puffing white smoke. So I suspect there's a head gasket or head problem, at least. The engine's running good, though, and a compression check shows 165-175 lbs in all cylinders. I'm a little baffled as to how the coolant is getting into the engine (or exhaust), unless it's a crack in the head between a coolant passage and an exhaust port. I've also had an intermittent problem in which the engine would run on 3 cylinders for several seconds after a cold start, and then run fine thereafter. And the #4 spark plug has a bunch of deposits that don't appear on the other 3 plugs.
The second issue - last fall, I had a sudden drop in oil pressure after a high RPM run through the gears. The engine also developed the valve lash "tick of death" at the same time, which it had never done before. I replaced the oil pump O-rings per the advice here, and the valve lash tick mostly went away, but it still comes back once in a while. And the oil pressure is still low. It used to run at the 45 PSI mark at 3000 RPM fully warmed up, but now it sits around 30 PSI or so at the same speed. The engine's been using some oil the past several thousand miles - maybe a quart in 1000 miles when it never used any before. There're no oil leaks to speak of - some seepage here and there. The bottom end is quiet - no loose or spun bearings and I know what that sounds like!
Now for the repair options - should I pull the heads, replacing/repairing parts as necessary? This would probably resolve the coolant problem, but what of the oil pressure problem? Even if I make sure to reseal the oil passages to the camshaft/lash adjuster galleries, is it likely that this will resolve the low oil pressure problem?
Or since I'd pull the engine anyway to rework the heads, should I just replace it? I've a question in to CCR to see what a replacement would cost - that will probably help answer the question.
And if I do replace the engine, it's probably not worth the hassle in going to an MPFI engine to gain just a few HP, right? I'm not interested in going to a turbo and I don't have any extra parts to convert from SPFI to MPFI. Unless someone out there wants to explain what it would take and has the stuff available for sale...
I welcome any thoughts.