Arfer67

Hi all
I am looking for some tips as I am trying to investigate where the oil is disappearing to in my 04 WRX PPP with 95K miles. A while back I had the drivers side rocker cover gaskets redone as they were weeping, and apparently this is a common fault.
This did not solve the problem, and I am now going through 0.5L of oil every 1K miles. So far I have replaced the PCV valve which was stuck, and this slowed the oil loss down a bit. While replacing the PCV valve I saw oil in the TMIC. There is no smoke at start up so I am suspecting the turbo rather than pistons/rings/bore wear, also kind of hoping it’s the turbo as this will be way cheaper to sort.
I had a good look underneath and there is no sign of a leak anywhere. I ran the engine with the oil filler cap off, I could feel the beat of the engine firing, although when I put I plastic bag over it, it did not inflate, infact it slightly sucked the bag inwards. I would assume excessive blow by would have inflated the bag ?
Due to a new sprog I cannot afford to keep sending it to a Subaru dealer, at least until I am sure what the fault is, and I am not wasting more money on work that doesn’t fix the problem.
So the next job was to take off the downpipe to check for unburnt oil, unfortunately all the vids on youtube show US cars where there is no brake servo, and steering linkage in the way preventing access. Had a go at this but gave in as everything seemed inaccessible and I didn’t want to damage anything in the process.
My other option is to remove the center decat section to look for unburnt oil, before I can do that I will need to order a new set of bolts though for the centre to downpipe joint as some kind soul stripped the nuts for me so I will have to hack them off, don’t you just love main dealers !
Will my plan to do the centre section show if oil is coming from the turbo? I would assume by the amount I am consuming it should have got that far down, unless it is all on the cold side of the turbo and getting burnt in the engine
Does anybody have any tips when removing the downpipe on a UK car ?
Have I made any incorrect assumptions in my investigations so far?

Cheers
Ian

ditchmyster

iTrader: (7)

If you're doing lots of short trips they do tend to consume a bit of oil at that sort of milage, particularly forged engines can use a fair bit because of the pistons. Also the breather system on the crank case covers and the way it feeds back into the air intake accounts for a fair amount of oil on these turbo Subarus. I think what your seeing is a combination of this and the miles the engine has covered.

My WRX has done 116k and uses anywhere between 250/350ml over a similar period depending on what sort of use it sees, yet when I do the 1300mile trip from Croatia to UK in one hit it barely uses 100ml.

Sounds to me like your getting worried and spending money on what isn't too far off normal consumption.

If it ain't broke, don't fix it.

Arfer67

I very rarely do realy short journeys, it is mainly to work which is 30miles each way so things get properly warmed up.

I would rather not wait until the turbo completely lets go on the motorway or something because I need the car to get to work and so would probably have to shell out for someone to fix it. I would rather try and track it down before it packs in if possible.

I have had the car since it was 6 months old, and it has only gone up to this sort of level over the past year or so, so I dont thing it is entirely due to gradual wear

Arfer67

So I finally got round to getting the centre decat pipe off………..well off enough to see up the downpipe, having bottled out of trying to remove the downpipe itself.
However the results are a little inconclusive, the soot was a bit greasy to the touch but there was no significant oil coating. Having regularly checked the oil usage, it has used approx. 700ml over the last 1K miles.
Could it be that the turbo seals have gone on the cold side only ? or is it looking like my next step should be a compression test ? which I guess is not going to be that cheap.

Having recently changed the MAF sensor due to age I got a good improvement in how the engine was running, it became a lot smoother and torquey. After reading around I also bought a front lambda sensor but I have not fitted it because I thought it would be better to clear up the oil problem first because I thought the new one would get sooted up straight away and would need cleaning in no time. However I have read that a duff lambda sensor can lead to bore washing, can this lead to high oil usage?……so should I put the new one in ??

I must say that at tickover the exhaust does smell a bit fruity as though the engine is running rich which would also explain why my MPG is down a bit from what I used to be getting. I might fit the lambda sensor as a last resort, unless anybody here has any ideas before I start handing over cash to someone to look at the compression

Cheers
Ian

Arfer67

Finally got a compresion check done and the news is bad. The results were between 120 and 130 for each cylinder. So this is probably how all my oil is escaping.

At this point a lottery win is crucial......................

Ian