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Air/Oil Separator replacement. Where?

jaykay127

Monza
Joined
22 Dec 2014
Messages
151
Well driving down the M65 last night 6th speed, 75mph looked in my rear view mirror to see white smoke. Immediately let off and pulled off the motorway. No lights on dash but stopped the car and went and checked the oil and water levels. Nothing untoward. I gingerly restarted the car and more white smoke for about 10 seconds then cleared. I drove back home via a different route as a precaution as I didn't want to breakdown on the motorway.

Did a bit of a check last night online and it looked most likely that it was the AOS giving up. Jasmine have confirmed today that it is very likely that but they would do full diagnostics. I asked for a rough estimate from them and and they said about £900 as its a full engine drop job.

Now I find conflicting information on this and wondered if anyone could give me the definitive answer regarding the engine drop situation, mine is a manual car BTW as this seems to be a factor in some answers. Also if anyone could recommend somewhere that may be able to do it without an engine drop locally, Lancashire, that would be fantastic.

I have driven the car to work today and apart from one second of white smoke on start up there has been no sign of anything untoward, car pulls and drives as it always does.
 
The AOS let go on my 4S... it manifested with a rising idle, followed by a horrid screeching noise, and a rapid oil consumption increase. I don't recall any smoke. It was diagnosed by removing the oil cap, and the screeching stopped (apparently air being drawn in through the crank case gasket or something). An AOS on the way out can be diagnosed by a manometer reading via the oil filler, which requires a custom fixing which some indies have.

But yes, the engine had to come out to replace the stupid thing, and £900 is much less than the £1500 I spent on the job and various other bits that broke when they were removing the engine. In retrospect this was very pricey, but once its in bits its difficult to argue. :sad:

You can get it out of a C2 or a .1 without removing the engine, but it requires the dexterity of a brain surgeon, and the usual response is 'never again'. I'm not even sure you can get it out of a C4 or a .2 without dropping the engine.

Regard it as an opportunity to attend to other jobs which are easy with the engine out like clutch, RMS, IMS check/replace, water pump, LTT, gearbox mount, brake lines as the AOS is actually very cheap in itself, then it wont seem such a waste.

Last time I frightened myself with white smoke it turned out to be nothing more sinister than the result of a loose coolant cap, so worth checking its not cross-threaded.
 
I have just got off the phone from Revolution Porsche in Leeds and they have quoted a 3 hour job to do it with the engine in as its a manual at £300 plus VAT.

Car had engine out for brake lines, clutch, gear cables, exhausts not long ago so really don't want it being done again so soon.

Fingers crossed they'll get back to me soon and can fit me in in the next week.
 
Perfect... I shall give them a call and drive up if mine fails again!
 
Wow! £300 is a great price for that job, even if it doesn't include supply of the part. I did mine myself on my driveway and it was such a horrific task I'll never do it again, at least not without dropping the engine first. Doing one in situ is easily the most difficult thing on the car I've ever done, and I've had the gearbox apart on the kitchen floor..
 
Good price. I've done two with engine out. It could be possible to do it in-situ, but it would need the patience of a saint.

The 1st aol had siezed on the block and had to use breaker bar. The 2nd one fell out. The next problem is refit as the rubber tube and clip are a nightmare.

It is possible to hydrolock if so much oil enters the combustion chambers, but lets not go there.
 
This is one of those jobs we used to be able to do in situe... hence 3 hrs ..
as these cars have got older and the fixings more corroded then it has become far more difficult ..

All i can say is the last one i attempted .. working with finger tips with corroded fixings and the brittle plastic pipes snapping leaving parts of it in the rubber pipes then i actually threw my toys out of the pram ..

That i must say doesn't happen often but i said stuff it to the office and dropped the engine .. there is a limit to what i can do at full stretch with little access when things break .

If the garage can do it in 3 hours then snap their hand off .. we wouldn't .. we quote for an engine drop these days .. basically because they don't want to lose mechanics that walk out after attempting this !!

Ok a bit of a joke there but you get the idea .. it might turn into a drop .. they might get it out in situ .. it's hard to say until its attempted .
 
If its a tiptronic then i think you can't do it in situ

I did mine on a manual with the gearbox off and it was difficult. Good job I have small hands.

Would not like to do it in situ. Or ever again to be honest.

£300 inc a new AOS is the bargain of the year, make sure you tip them well.
 
Thanks for all the responses. I am booked in next Wednesday at Revolution Leeds.

Incidentally I started the car this morning to see how bad the white smoke situation is so I can assess whether to drive it to Leeds or trailer it and there was no smoke at all?! Check all levels, all fine so I decided to use it to drive to work. When warmed up I gave it a squeeze of throttle and it was fine.

At this stage of the likely AOS degredation is this plausible?

Thanks
 
Yes - it's very feasible that it's only partially failed.

I bought my car with a partially, though only slightly) failed AOS and drove around like that for several years(I had no idea that it was faulty) . When it let go I was very lucky that I was at idle, as it just stopped. I tried to start it but it wouldn't turn over, and it turned out to have been hydraulically locked by literally half pints of oil in several cylinders. Had it happened at speed then it would have been the end of the engine.

Don't let this scare you though, given that I drove around for several years before mine let go, I think you'll make it to work and to the garage.
 
Small update.

Just got off the phone with Danny from Revolution in Leeds and the Air Oil Separator they have removed is a motorsport one so will be more than initially quoted as original part should have been about £80 not the £490 it is now. He thinks the car may have had some work on the engine in the past prior to my ownership. I could go back to original AOS but it would need new pipes and connectors which he said would end up being a similar price overall anyway so I have said to just order the motorsport one and fit it as it was.

Stay tuned for more exciting updates.
 
Aren't the motorsport ones dual chamber and thus don't fail like the standard ones do?

I'd be questioning your diagnosis on it being the AOS. :dont know:
 

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