hi peeps, just got hold of another scooby , 02 plate wrx, Sti engine upgrade , full decat etc etc mapped by Duncan graham @ 343bhp. All seemed well when I've noticed some blue smoke. It smokes when you excelerate after a long overrun, so you boot it down the road , let off the the accelerator for a few second then back on and a big cloud of blue smoke appears , I'm hoping it's just a turbo what not really my area of expertise .
thanks

 

Any ideas anyone ?

 

So not a lot to go on to be honest, but smoke on the over run is usually and indication the turbo is buggered. well when I say that shaft play and it using some oil. have you noticed the car using oil and needing regular top ups.

 

I only got this one yesterday , not much history with the car but a hell of a lot of cash been put into it I can see this, it doesn't smoke on the overrun at all it smokes on boost an when you re apply the throttle after the overrun , it has a vf34 turbo and previous owner says it's been on for about 3 months 2nd hand with 50k miles on it. I'm going to drop the down pipe and check the breather pipes when I get a chance but I was just wondering what the general consencous was with people more in the no , I've had over 20 scoobys of all generations over the last 20 years and drive them like I stole them and have never encountered a smokey scoob so it's new terratory for me . This is a sale car so I need to fix before I move it on .

 

Blue smoke would suggest it's burning oil. I think there is only a few ways oil can get in to be burnt:

Internal leak in the turbo - oil gets into the intake air charge under load, as it passes through the turbo. A check might be to take the intercooler off and check inside that, the turbo outlet and throttle body. There will be some oil in there anyway (a mist) because of the pcv but a lot would show an issue.

Head gasket - oil leaks past the gasket into the combustion chamber (i think this is unlikely unless your coolant shows signs of contamination also?)

Piston rings - if the oil sealing ring is worn or the bore is scratched this could cause it. A compressiom check and bore scope (camera) mighy identify it.

Stuck or failing pcv (positive crankcase ventilation) valve - pressure can build up in the crankcase and cause havok that way

 

I'd suggest if it was an internal issue, then the smoke would be present when cold and then clear as the engine warms up. If it's internal and it blows whilst hot then it's pretty serious and there would be other symptoms. So I'd say breathers or turbo.

 

 

stuff related to overrun and going on the power could still be rings, the rings to expand in to the bore under load and 'relax' under lower load or overrun. The oil leak could be occurring the in the transition, and if the rings are worn the overrun condition could be enough to let some oil through. A compression check might be the next best thing to do.

Something else that has sprung to mind, that I missed from the previous post, was valve stem seals as another possible entry point for oil.

 

yeh I'm leaning towards a more complicated problem than a turbo , looks like I might be breaking this beast now