1992 Chevrolet Caprice base model, 324,xxx miles, white/light gray(?) smoke from tailpipe. Mechanic says not a blown head gasket or cracked block, but cant explain smoke. Doesn't overheat, but had one episode since i bought/took ownership in Feb 2021. Doesn't lose coolant but does burn a little oil. Runs, drives fairly smoothly, it's just the heavy smoke. Smoke doesnt smell like coolant or gas. What else could explain the smoke or mimic a blown head/gasket?
Worn out piston rings. You could do a partial re-build (rings and rod bearings) while the engine is in the car.
@Doc meant to up vote, sorry about that! Finger hit the wrong button, haha.
@justin-shepherd you can still upvote (to neutralise an accidental downvote) and vice versa.
It's all good. Thanks ITWT.
Do a wet/dry compression test to see if it's the rings, and how far gone they are. Note that on some engines, valve guide wear could also be causing the oil burning. Which engine does your Caprice have?
5.0
Typically white smoke is coolant, but you say youre not losing any. Good chance its either worn piston rings or bad valve seals. A wet/dry compression check could determine this. I know on some older engines you could run a thicker oil and it'll slow down consumption. I dont think id do a practical rebuild as stated above on an engine this old with that many miles
leak down test should pinpoint your problem
compression test as well for determine motor health
