ok guys...

well just to clarify..i have NO i mean NO external leaks, but it did take me 3 attempts and 2 shops before i could find someone who could fit that oil return pipe before it stopped leaking...


the turbo was rebuilt by the most reputable builder i could find...and in fact only the casing (1/2 of it) was retained...the shaft was badly scored apparently...

the change of turbo didnt affect the oil usage one bit, so unless both turbo's were leaking equally badly.....

so then i have 3 questions

1. foolproof method of testing rings
2. foolproof method of testing valve oil seals
3. foolproof method of testing valve guides...

ideally without taking the head off..

i really want to diagnose this as i have spent thousands (quite literally) trying to sort it on the next 'well its probably this' idea none of which have made a bloody diference!

That T5 is looking awfully attractive and cheap to run right about now! (i worked it out i can have volvo put in a new gearbox for less than i have spent on the 940 chasing this bloody oil usage!)

Hey Kick, get a head from the bone yard 89 and up (better valve guides) and have it redone by somebody that has done one before. Some Sat. afternoon swap it out and no more oil usage. Good luck. Pauli

if the turbo was rebuilt it could be defective.is there oil in the turbo housing,intake and exhaust sides.
a friend of mine sent his turbo to an un-named turbo rebuilder in waco 3 times before they got it right.they kept telling him it other problems with the engine,pvc system,oil box...etc... all of which were checked or replaced with out helping the problem.
he got pretty good at pulling the turbo and just a bit angrier each time.
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83 242 DL -132k, 92-965-201k, 94-965-208k, 84-242 GLT-Gone, but not forgotten,83-245GLT-1'st brick (the 1'st 3 currently on the road)

I would say that it's not possible to rule out the turbo as a suspect, even if it is newly rebuilt. It's always possible to catch the rebuilder on a bad day.

I would suspect the rings are probably okay as well... however I wonder if this engine has been severely overheated in the past. The smoke at high vacuum makes me wonder about the valve seals tho. Aluminum is much easier to damage than cast iron.

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alex

I had a situation similar to yours where under boost there would be smoke and an increase in oil consumption. My problem was simply a leaking gasket from the turbo oil return pipe into the block. This is a simple o-ring gasket that seals the turbo oil return line to the block with a compression fit. Under boost I would see white smoke tailing from my vehicle. If the smoke is white and doesn't seem to be coming from your tailpipe, I'm even more inclined to think this might be it. When the oil drips from the gasket it drops onto the exhaust downtube and smokes immediately. Check where the oil return pipe from the turbo enters the block and see if there's any oil residue or if there's some oil on the oil cooler hoses. This condition wouldn't smoke when idling or if rev'd in the driveway. The gasket cost $4.50 and there are instructions for the install in the faq's. B230's are amazing engines, in my opinion the best Volvo ever made.

Something to take a look at anyway, seems it seems like your motor might be in good shape otherwise.

Mike

1993 944t 110K

I do not think it is possible to wear out rings on a B230 in 150K. And no, it is not "did not shange oil every xxx miles". I would suspect the turbo, who rebuilt it and so forth, but you will have to separate the turbo from the valves in the diagnosis. 850 with fewer issues than a B230.......I don't think that is a safe assumption.