Turbo oil seal symptoms

[dern]

Afternoon,

The impreza turbo has started smoking today on startup. I checked the oil a fortnight ago while I was in there changing the ht leads and it was bob on. I've done about 100 miles since and since changing the ht leads the car has been running really well. Today I fired it up after it had been sat there all week and blue smoke came out of the exhaust. It soon cleared and running it hard causes no smoke and coasting in gear and the accelerating hard causes no smoke. If I sit in it in neutral and rev it up and let it fall back, rev it up then it smokes again. I checked the oil and it's now sat just below min. I won't drive it again until I've topped the oil up and will be doing a compression test and pulling the intercooler off to see if there's any (lots of, there's always a bit apparently) oil in it however, I'm in the middle of my daughter's birthday weekend so can't do it now. It's not used any oil in 18 months except in the last 2 weeks.

Do these symptoms sound like turbo oil seals?

Cheers,

Mark

[stevieturbo]

What turbo is on it, and does it make any unusual noises on boost ?

[dern]

To the best of my recollection a standard td04 and no, nothing unusual noise wise.

Here's an odd thing... I took the air filter out as it looked pretty badly gummed up (it's a k&n) even though I only serviced it last autumn just in case the engine couldn't get enough air and was pulling it past the turbo oil seals or past the valve stem seals... all the smoke has gone, really dramatic difference. Could this really have been the problem? Could the turbo suck oil past the turbo seals if it couldn't get enough air or could this be another problem?

I'm assuming that if the cause of the oil was the engine itself then simply removing the air filter wouldn't fix it

[stevieturbo]

Not sure about it sucking it from the turbo.

but if the air filter was very restrictive, it could cause there to be more crap from the breather system drawn into the engine.

Is it a genuine K&N ??

Some of the crappy filters for sale on ebay, are unbelievable. Im amazed cars even run with them on

[dern]

stevieturbo said:

Not sure about it sucking it from the turbo.

but if the air filter was very restrictive, it could cause there to be more crap from the breather system drawn into the engine.

Ah, ok, that makes sense.

stevieturbo said:

Is it a genuine K&N ??

Yes, I serviced it quite recently (end of last year) but it just seems to have acquired a layer of gunk from somewhere.

[dern]

Ok, have confused the crap out of myself today... I cleaned the air filter and refitted it today. I also removed the intercooler and the pipes looking for oil. I found some as expected but a bit more than I thought I should. I think that this means that oil is going in to the engine to be burned off via the throttle body than past the rings or the stem seals. It could be forced in either from the turbo seals if they're failing or coming through the breather system either sucked there due to the blocked air filter or forced there by blow by. Anyway, I refitted the air filter, topped up the oil and went for a run. Mainly there was no smoke but on occasions I still got some blue smoke. I rechecked the oil to make sure I wasn't low again and although it was spot on before now it's overfilled. I drove slowly home and there's oil in the intercooler to throttle body pipe again.

What I think has happened is that the airfilter was blocked. This sucked oil vapour up through the breather system (as you suggested) and that was burning off. Taking out the air filter seems to have corrected this as has subsequently cleaning the filter. However, I somehow managed to overfill the damn thing (I don't know how, maybe there's some air in the dipstick tube or something, wouldn't be the first time, or maybe I'd inadvertently parked it on a sloped bit of the drive) and now the overfilled engine is blowing oil vapour back in to the inlet manifold.

I guess it could be the turbo seals but then you'd imagine that I'd get loads of smoke when driving hard and I don't. I guess the engine could also be shagged and I'm getting blow by causing crank case pressure blowing oil vapour in to the inlet system but again I'd imagine I'd be getting loads under hard acceleration and I'm not.

What I'll do next weekend is fit a brand new air filter (I think this k&n is at the end of its life), empty the excess oil out, clean out the oil in the inlet system, do a compression check and see where we go from there.

Any thoughts?

Cars eh?!

Edited by dern on Sunday 6th April 19:32

[Mr Whippy]

New paper filter (aftermarket ones are wank and a longer term liability imho)

Sort oil to the correct level (drain some out the dip-stick pipe)

Drive and keep an eye on oil level.

Dave

[dern]

Mr Whippy said:

New paper filter (aftermarket ones are wank and a longer term liability imho)

With this problem and the ever present risk of over oiling it and knackering the MAF I'm beginning to come to the same conclusion and have some OE paper ones winging their way to me as we speak

[Mr Whippy]

dern said:

Mr Whippy said:

New paper filter (aftermarket ones are wank and a longer term liability imho)

With this problem and the ever present risk of over oiling it and knackering the MAF I'm beginning to come to the same conclusion and have some OE paper ones winging their way to me as we speak

I have no conclusive proof either way, just when I come to do the air filter cleaning I have to put something in the airbox, just in case something flies in and through (who knows)... then I may well forget I've taken it out and cleaned it (do they ever clean RIGHT out with water and washing up liquid?), and it's sat drying on the radiator, and I set off without a filter!

Then how much spray to put on, where did I leave it? Is that enough, a bit more just in case, oh, now the MAF sensor is gonna read dodgy for a month.

Replace. Ah, finally.

OR, get a paper one. Swap it. Done.


I'm sure in extreme states of tune when you want double the power or something, then maybe some exotic exposed foam filter is a good idea, but for the majority of people a good new paper filter is damn good imho.


I aim to do some testing this summer for my car, but I think modern 'performance' filters for normal ish road cars are just snake oil. Gone are the days of inefficient pancake filter housings on top of old carbs and stupidly inefficient intakes...

Dave

[dern]

Mr Whippy said:

I have no conclusive proof either way, just when I come to do the air filter cleaning I have to put something in the airbox, just in case something flies in and through (who knows)... then I may well forget I've taken it out and cleaned it (do they ever clean RIGHT out with water and washing up liquid?), and it's sat drying on the radiator, and I set off without a filter!

Then how much spray to put on, where did I leave it? Is that enough, a bit more just in case, oh, now the MAF sensor is gonna read dodgy for a month.

Replace. Ah, finally.

OR, get a paper one. Swap it. Done.

Lol, I know exactly what you mean. It came with it and I had a k&n cleaning kit in the garage and halfords never seemed to have a paper filter in... etc. Basically apathy always won out

Mr Whippy said:

I'm sure in extreme states of tune when you want double the power or something, then maybe some exotic exposed foam filter is a good idea, but for the majority of people a good new paper filter is damn good imho.

I aim to do some testing this summer for my car, but I think modern 'performance' filters for normal ish road cars are just snake oil. Gone are the days of inefficient pancake filter housings on top of old carbs and stupidly inefficient intakes...

I'm no authority but from what I've read a replacement k&n panel filter flows pretty much the same air as a standard one. I believe that the advantage comes down the road. A paper filter works by having holes in it that are smaller than the stuff you want to filter out but the result of that is that as dust gets filtered out the filter gets gradually more blocked up so that the airflow is eventually restricted. An oiled filter works by having holes in it that are much bigger than the stuff you are filtering out but because they are oiled the dust hits the oiled surface and sticks. In this way you are filtering out the same dirt but not restricting the airflow. So the theory goes that the airflow with a paper filter reduces over time but stays (more) constant with an oiled filter.

Still with a road car... who cares

Edited by dern on Monday 7th April 15:56

[Mr2Mike]

dern said:

I guess it could be the turbo seals but then you'd imagine that I'd get loads of smoke when driving hard and I don't.

Worn turbo seals show themselves much more at idle, and when you put your foot down after the engine has been been on the overrun. When hooning, the positive pressure in the compressor and turbine housings helps keep oil on the right side of the seals.

[dern]

Mr2Mike said:

dern said:

I guess it could be the turbo seals but then you'd imagine that I'd get loads of smoke when driving hard and I don't.

Worn turbo seals show themselves much more at idle, and when you put your foot down after the engine has been been on the overrun. When hooning, the positive pressure in the compressor and turbine housings helps keep oil on the right side of the seals.

Hmm, that does match the symptoms... I'll eliminate the other possible causes and go from there.

Cheers.