i All,
I'm at a loss. I've a 2001 986s which is somehow managing to suck oil into the top of the engine and need some 'out of the box' thinking becuase I don't believe it's the AOS, and virtually every response to anything to do with exhaust smoke is blamed on the AOS.
For starters, I've already fitted a new Porsche AOS, and changed the oil being very careful to ensure it was only filled to half dipstick.
I've had the car about 4 months but used it very rarely until the last 2 weeks since the sun started shining!
The symptoms seem to be that the car is perfect, absolutely perfect, so long as you don't give it too many revs. I've used it for the last 2 weeks to pootle round town and for work a couple of times (M4, 100 miles round trip), so all is perfect if the car is used 'normally'.
However, if the car is used with some 'spirit', oil is getting somewhere it shouldn't. Last night I went out for dinner, had a chance to use the car on some A roads and enjoyed giving it a bit of stick, up to 6K revs a few times. Left the pub an hour or so later and there was a cloud of smoke at start up, for about a minute. Then, on the way home , gave it some revs , in third, on a dual carriageway and there was a drop in power and an almighty eruption of smoke out the exhuasts... enough to totally obscure over a 1/4 mile of dual carriageway. Lifted off and smoke cleared, carried on home. Then this morning, start car up and 30 secs of thick white smoke. And I know it'll do that a couple of more times as oil seeps down into the engine over the next day or so as this is not the first time it's done this!
This is about the 4th time and explains why I've already changed the AOS and the oil. It only happens when the the revs are high and under load. It's as though oil is being sucked up into the top of the engine (I mean the inlet side of things) when the engine is working hard, and then either getting into the pistons to burn off there and then, or being 'stored' to allow it to slowly seep down ino the engine to be burnt off the next time the engine is started.
it displays none of the symptoms of the AOS on the way out, no vacuum etc,,, and the oil is only half filled so no overfill possible.
I can only think maybe there's some kind of half blocked tube or something in the inlet/emissions side of things that's allowing oil to get where it shouldn't during hard engine use. But I don't know where to even start to look!
Probably explains why the car has had a few owners recently, not much point having a Boxster if you can't give it some every so often!
And I suspect the last few owners have given up trying to fix it.
Any ideas anyone? I know a few others have had this happen as a one off, but this is 4 times for me, and I can't find any technical reason for it.
Cheers all for any advice.
Piersman
Have you checked to see if there are any codes? Are you certain it is oil that is burning i.e. has the oil level dropped after all the smoke clears? (sorry couldn't resist). It almost sounds as though your getting oil past the rings which could be worn or damaged, how many miles on the car?
Have you taken it to a dealer for their analysis with a PSII?
Hiya, I did take it to a specialist and they checked and cleared the codes, there were some I believe triggered the first time it did it when I had an engine warning light come on for about 30 secs before it cleared itself. No codes have been triggered on subsequent episodes because I've spotted it quicker and lifted off quicker.
It is definitely oil , and I do seem to have a drop in oil level when it happens. The car has 72K miles on the clock although I've no way of confirming that or knowing how it was driven.
Someone on another forum has suggested piston rings or bores so it seems I need to get it checked in for an engine check.
Clearing codes does not make them go away as they will reappear after the motor cycles through the series of on board diagnostics that are constantly run by the ECM. I think you are doing the correct thing in getting a good mechanic to check it out. Let us know what is found.
I'd suggest a leak down test is in order to see if your leaking past your rings into the crankcase (and vise-versa); or likewise, to see if your top end is leaking past your valves.
