Puff of Smoke After Hard Acceleration

[Santawillis]

As the title says, I observed a puff of smoke coming out of the exhaust after very hard acceleration, this does not occur every time and is intermittent, any thoughts?

 

Valve Guides?

[John76]

Is the puff white, blue or black?  White = coolant.  Blue = oil.  Black = rich mixture.

Hard acceleration creates low manifold vacuum, so if the smoke is blue, then most likely marginal ring sealing instead of valve guides.  Smoke on heavy deceleration (very high manifold vacuum) usually is valve guides or seals.

 

[Santawillis]

John,

 

Hard to describe the color but I believe it leans a bit more to blue. Coolant level is stable and temperatures are running great. Engine seems to have been recently serviced for a head gasket but the history is murky. It was certainly taken apart!

[visionaut]

You can also get smoke after accelerating (when you lift) and when decelerating (when you engine brake) if your brake booster check valve is oriented wrong or busted…

 

IIRC, it’s whitish too.. with a tinge of blue? 

Edited July 25, 2023 by visionaut

[Leucadian]

I had similar, if not identical symptoms.  

 

My issue turned out to be a stuck valve guide...and bad rings.  You can always run a compression/leak down test to attempt to rule out the latter. 

 

Is your oil consumption higher than normal?  

[Santawillis]

@Leucadian tough to measure oil consumption at the moment, my oil pan gasket is leaking when the oil gets up to temperature so I have had to add a bit of oil over the last 6 months. I may try to run some Marvel Mystery Oil to see if things improve, if not then a teardown is in order!

 

 

[Son of Marty]

If the head was refreshed when the head gasket was changed it;s common for the lower end to smoke and loose compresion as the head,is near new and doing it job at high efficienty and the rings are tired. Oil's cheap, rebuilds not so much.

[Santawillis]

1 hour ago, Son of Marty said:

If the head was refreshed when the head gasket was changed it;s common for the lower end to smoke and loose compresion as the head,is near new and doing it job at high efficienty and the rings are tired. Oil's cheap, rebuilds not so much.

I am A-OK with topping off oil once in a while, especially while I save for a full engine refresh

[TobyB]

That's pretty much normal, if you're not losing more than a quart every couple thousand miles.

 

The high vacuum against both rings and valve stem seals draws in more oil than needed, and

it burns off.  Just a little oil is helpful to keep the stems and cylinders lubed, so a bit extra's 

pretty darned common.

 

t