I have a 1984 z28 with the l69 v8 .my car runs fine but randomly the check engine light will pop up,tbe idle gets rough and he tail pipes spit white smoke... any ideas whats.up?

 

your burning oil or your burning coolant. check your heads for cracks. do you have any loss in compresstion? when dies this happen? cold... hot?

 

As i said its random... the car will be fine and the check engine light will come up outta nowwhere... the only thing thats really an indicator is tje smoke and a slight loss in power

 

Have you checked your coolant and oil?

Verify your fluid levels. You should also check if the coolant is still green and clear. If it's dark or murky that usually means you have oil in it. Check the oil too.

Whenever I've blown a head gasket it was just full on smoke screening. Maybe it's just a slight leak.

 

One thing you could do is mark your reservoir with a marker and see if you are loosing coolant this way. I did it with a 350 tbi, and sure enough I had a cracked head. The oil looked good, the coolant wasn't contaminated, but I had a small crack in one of my heads, causing me to loose coolant.