Dreaded Blue Smoke ....

[Jabba]

Wifes 2001 1.8T has recently started to kick out clouds of blue smoke when starting from cold - but ONLY when starting from cold.

The car has been using oil for some time but no obvious signs have been present as to where or why.

The smoke lasts for around a minute during which time the amount gradually reduces then clears. There is no smoke at all on subsequent starts when the engine is warm or has run recently.

In the old days I would have said valves but these damn Cats make diagnoisis real hard (Smoke on overrun = valves, smoke all the time = bores) the opinion seems to be though that smoke with a hot cat seems to be always zero, there is no smoke on tickover, overrun or at any other timeonce this initial period is done.

Anyone had similar symptoms - what was it in the end if you cured it?

[GTW]

Given your description, the most likely suspect is surely the stem seals. Not got any other nasty top-end noises or symptoms?

I had a Bluebird once that did this and it was just one stem seal that had disintegrated:(

Gaz

[Jabba]

Car starts and drives without issue, no odd noises, no whining from the turbo, no rattles etc.

If I could get it to smoke once hot on overrun or something that would confirm it for me that it was a stem seal but it doesn't

[GTW]

Hmmm, curious. But if there's no other symptoms and it's dribbling into a pot/pots on cooling down or overnight from the rocker box, it can only be down through a valve?
Blow-by/PCV would send it back to the sump. Problems with the HG or bores would be pressurising elsewhere and causing other signs.
I don't think smoke on overrun is the only conclusive evidence of stem seal failure, so my money's still there.

Gaz

[Jabba]

I agree also, my belief is also stem seals although the amount of smoke is considerable so I am also suspicious of the turbo seals, more so since there is no cammy rattle or lifter issues, no misfires or starting problems. I'm not sure how much oil is capable of sitting under the lifter buckets in a position to be able to leak down. Trouble is I would expect turbo to be constant smoke unless it is just early stages ??

I only noticed it recently after fixing idle speed problem, the engine was not stable when under load in traffic and was kangaroo powered. I fixed it by cleaning out the throttle body that was in a disgusting state, it was full of a substance that looked like golden grease, it also had lots of black sticky crap in there too so I guess the intercooler etc is also full of crud and could do with a good spring clean. I put the smoke down to the carb cleaner fluid I was using.

I have run with the oil filler removed and can detect no evidence of back pressure or over pressure - although it is a little grubby in there which is disappointing for a car run with nothing but fully synthetic oils.

It is hard too to decide if it is overfilled, every dip of the stick is a different result some over / some under - oh for the days when oil went black ;-) but the oil stays pretty clean ... and yet the top of the engine is grubby - go figure.

I was cleaning my car when the wife went out and I saw it again and no way it was carb cleaner now.

But I have got a little lazy in my old age, arthritis and MS mean that my capacity for pulling cars to bits is somewhat reduced although the enthusiasm is high as it as ever been, I'll throw it at an independant and get it checked over (compression, turbo pressures etc etc) and post the results.

Thanks for the input.

[dc1]

Turbo seals went on mine at 100k, recon turbo fitted and problem gone. Remove the intake pipe on the turbo and check the shaft for excess movement and check for oil in the pipe and the inside of the compressor housing.

[GTW]

But I have got a little lazy in my old age, arthritis and MS mean that my capacity for pulling cars to bits is somewhat reduced although the enthusiasm is high as it as ever been.

With you on that one, although for me it's CP and age. I seem to groan and creak a lot more these days:o. I've strong links with my local MS Society, so have a better understanding than most.

Gaz

[GTW]

Turbo seals went on mine at 100k, recon turbo fitted and problem gone.

Wouldn't this show up on normal running (turbo spooling) at temperature more - when the oil's hot and thin, rather than a cloud from cold only?

Gaz

[carl s]

Sounds like valve stem oil seals as mentioned above. What used to happen on an old Pinto engine of mine was that overnight the oil would seap through into the bores as it lay in the top of the engine. After startup the oil had been burnt off and everything was fine, until it was sitting there overnight again...

[CrazyDog]

Wouldn't this show up on normal running (turbo spooling) at temperature more - when the oil's hot and thin, rather than a cloud from cold only?

Gaz

I've had this problem before. It was caused by oil leaking from the turbo down into the exhaust when the car was left idle. When I started the car the exhaust warmed up and burnt the oil, thus producing smoke. Once it had all burned away it didn't seem to smoke any more.

Check the shaft play in the turbo... if there's significant movement then there's your problem - oil is escaping through the seals.

If this is the case then you may be losing oil whilst driving without noticing. Try going out in the dark, and when a car is behind you with its lights on, boot it and see if you can see smoke in your rear-view mirror.

p.s. I don't know VW's but I hope that helps.