Volvo 850 '96 T-5 MTE Upgrade / Blue smoke @ idle

[onnaj]

I bought a Volvo 850 T-5 (which runs also on lpg) yesterday with a 3" downpipe and a MTE (ET) upgrade (about 285 hp and 420 nm) and it has the next problem.

At idle when i press the pedal a little bit and then lift, blue smoke comes out of the exhaust. It also smells like burnt oil.

When i accelerate with little or full throttle no smoke is seen. But when I accelerate fast and then changing gears or lift the pedal a blue cloud will appear.

Sometimes...not always..it also seems theres coming a little bit of smoke from the dipstick hole. I can also see some (old) oil drips on the inlet. Seems there's too much pressure.

During full throttle it seems that te car is hestitating a little bit its not one fluent power band i believe. Sometimes the turbo indicator goes to it max but sometimes i think it doesnt.

When changing gears at very low throttle i also noticed that the rpm raise with about 500 rpm and then slowly return to idle (when pressing the clutch). When i accellerate fast the rpm wouldt raise during clutch/changing gears.

The previous owner did a rebuild on the head and replaced the turbo for a rebuild one. He placed the turbo hisself and even then the blue smoke didnt disappear. Could it be that he mounted it wrong?

He got crazy from the oil usage of 1 litre for every 1500 km and the blue smoke and some little details more and therefore sold the car.

Any ideas before that im going to change the turbo again? I cant imagine the piston rings are bad, cause the engine itsefs runs very smooth and during accelleration theres no smoke at all. Normally when piston rings would be bad there would be smoke during accelleration.

Thanks for the replies.

Janno (from Holland)

[vegasjetskier]

It could be that the valve guide seals are bad. When you let off the throttle it creates a very high vacuum in the intake tract. if the valve guide seals are bad, oil will be drawn in along the intake valve stem and cause the blue smoke. Did the previous owner replace the seals when he rebuilt the head?

Also, if you are getting a lot of crankcase pressure it probably means that the rings, pistons or cylinders are worn out or the ring packs are stuck. These things can also result in excessive oil consumption as oil is sucked past the piston when you let off the throttle.

You can try a dose of www.auto-rx.com and see if that helps (primarily by cleaning up the ring packs and allowing them to seal again - might also help with the valve guide seals).

[onnaj]

The previous owner did a complete rebuild of the head including the valve seals..so that couldnt be the problem.

Hope it is the turbo. Can buy one for abt 175,- euro's, so i'll give that a try maybe. If the smoke is gone or a lot less...i got the point...otherwise... a new engine except the head is needed.