Blue Smoke at Idle!

[Cody86]

Hi,

My brother has a FG XR6T, he had it tuned about a month ago. 

At idle it blows a heap of smoke, it doesn't blow smoke when crusing or under acceleration or de-acceleration. 

Checked the PCV valve it has suction and the valve still moves in it, checked the oil feed line and it's supplying oil. It does have some blow by in the intercooler piping, however there is no odd noises coming from the turbo, and the play in the turbo shaft is minimal. 

 

Would it be the valve stem seals? It started doing it after getting it back from the tuner, the smoke is blueish colour and not black, checked the spark plugs and they are covered in white ash on the electrode and insulator.

 

Any help would be appreciated.

Thanks

[k31th]

 

It does sound like valve stem seals... especially if the seal re-seals once the engine is warm as compared to cold... or piston rings if the valve stem seals are OK.

[Cody86]

Would it be valve stems if the spark plugs don't have oil build up on them? The plugs are dry but have white ash on them. 

[k31th]

white ash could be extra combustion temperature due to running lean which can either be a symptom or cause of piston ring failure.

[Cody86]

I checked compression today on all cylinders, came back at 150 for each, no difference in any of them. It doesn't smoke at all when cold, only after it has been sitting for awhile. There is oil on the bottom of the turbine housing, so I'm leaning towards a leaking turbo. 

Also checked the oil drain on the turbo, and it is still draining the oil back into the sump, also checked the oil feed and it is supplying oil. 

Edited 06/10/20 02:50 AM by Cody86

[k31th]

Probably not piston rings at that sort of compression value, so good news on that front.

 

It's normal for there to be a little pool of oil in the compressor housing of the turbocharger due to the PCV system venting back into the intake. A catch-can setup can avoid this sort of oil buildup at the turbo, piping & inlet manifold.

 

So there's no smoke when you're accelerating, decelerating, or when it's cold... it's only when it's warmed up idling?

[Cody86]

Yes ordered a catch can set up.

 

Yes that is correct it's only smoking when it's warmed up idling. After you drive it around the block the smoke goes away, than once you idle again for like 10 seconds it starts smoking again.

[k31th]

honestly I can't think of a circumstance of operation that'd cause it to only blow smoke on idle/warm... idle/cold or cold makes sense, but idle/warm combination and no throttle/slowdown affects it doesn't make sense to me... hopefully somebody else can offer a thought pattern to help