[Fatlip]

Hi guys. I just had my vq40 completely rebuilt and after 2500 miles i started getting white smoke out of the exhaust. Brought it back and the found a bad valve seal in #6. The pulled both heads and replaced all the seals pcv and both head gaskets. Upon start up it smokes for about 5mins then it goes away. There hasnt been any loss of power. What else could it be? Thanks guys.

 

[LittleBull]

It depends, white smoke is a indication of a coolant leak.

But it's also normal when the vehicle's warming up since water is a by product of
combustion and it condenses in the exhaust until everything warms up enough to keep
it in a vapor state.

Given that you've had issues with a leak you may just be hyper sensitive to your
exhaust's state. Check another vehicle and compare your start up exhaust to theirs.

 

[Skibane]

Typically, you can smell a coolant leak in the exhaust - Smells like antifreeze.

 

[Fatlip]

Its a lot of white smoke.

 

[invasion08]

Are you losing any oil? Also you said it has been rebuilt, why? And what did they replace/do?

 

[Fatlip]

Rod and main bearings timing set piston rings valve seals head gaskets pcv were replaced. The block and heads were also machined.

 

[B-Mackin]

Valve stem seal.

 

[Fatlip]

Already pulled both heads. They found bad seals in #6. Replaced all the seals in both heads and its still blowing smoke.

 

[AndysLog]

they could have done a shitty job.

if its only lasting 5 minutes, that means there is either enough heat building to expand the metal and fill all the gaps with oil, or oil is just filling the gap.
either way, it sounds like they didnt really do you justice.

rings/valves would be my two main jump points for smoke on startup but goes away as it warms up.