Stop Smoke

[MWalker1]

I have a chevy 305 5.0 and whenever i hit the gas it smokes and it smokes at idle what can i do

 

[foxtrot]

What color is the smoke?

 

[chevynut]

When it comes to using oil, an old school seat-of-the-pants mechanic would say that smoke on startup and deceleration (high vacuum) is valve guides while smoke on acceleration (low vacuum) is rings.

If it's an automatic trans with a vacuum modulator, I've seen them let transmission fluid through and make alot of deceleration smoke.

 

[Evan11]

If it smokes constantly, its likely the rings. If it smokes only on start up or your first take off, or until it warms up, its likely the seals. I would try a thicker oil like a 10w40 or 20w50, it won't cure it, but it will reduce the smoke.

 

[MeanBuicks]

Recently, the 271,00-mile 5.7L TBI motor in my Olds Custom Cruiser wagon suddenly developed a propensity to smoke heavily but only under deceleration when the throttle was completely lifted. Stumped everyone locally and on the forums as we eliminated various causes. Turned out to be a head bolt adjacent to cylinder #7, located next to the valve spring, that broke flush with the deck. It not only created an oil path under the bolt head but unloaded the head gasket right there allowing oil to be pulled in under high vacuum. :|

As others have said, some diagnostic time to eliminate causes and hone in on the real culprit is always the order of the day. Good luck with it.