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C2S frustrating leak from top of engine

gav525

New member
Joined
3 Dec 2019
Messages
23
Before I send the whole car to a specialist who knows what they're doing, I just thought I'd check here to see if anyone has any ideas at all.

Noticed some oil drops on the floor after parking up after a drive. After investigation on the ramps, I could see it was tracking down the bellhousing and was coming from the top of the engine. It looked like it was coming from round the oil cooler, but hard to see where it originated from.

Stripped what I could and have so far replaced oil cooler O rings and air oil separator. The AOS lines look OK and no signs of any oil coming from them. No oil in the crossover pipes either.

Got it back together and its still leaking. Where else is there to check that I could be missing? Doesn't look to be coming from oil filler tube either.

Anyone experienced a similar leak before?
 

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If it was a crack in say the AOS , a pipe from it or the filler neck then you would have other issues .. basically the crankcase would not be sealed and you would have lambda sensor issues due to a weak mixture ... fault codes.

To me .. you have replaced the oil cooler seals but logically there could be some corrosion around the seals or the cooler itself is leaking .. i suspect it is .

You have fresh oil running down and it looks to be a fair amount , it also looks like its actually coming from the cooler ..

It's up to you .. you can get a garage to look at it .. they will probably start with the cooler to be honest or you can replace it yourself ..

With some items .. you simply have to replace to move on and in this instance .. i can't think of anything else there .

if doing yourself then please take pictures of the cooler and underneath it so we can see .
 
deMort said:
If it was a crack in say the AOS , a pipe from it or the filler neck then you would have other issues .. basically the crankcase would not be sealed and you would have lambda sensor issues due to a weak mixture ... fault codes.

To me .. you have replaced the oil cooler seals but logically there could be some corrosion around the seals or the cooler itself is leaking .. i suspect it is .

You have fresh oil running down and it looks to be a fair amount , it also looks like its actually coming from the cooler ..

It's up to you .. you can get a garage to look at it .. they will probably start with the cooler to be honest or you can replace it yourself ..

With some items .. you simply have to replace to move on and in this instance .. i can't think of anything else there .

if doing yourself then please take pictures of the cooler and underneath it so we can see .

Thanks for the reply, I was hoping someone like yourself would reply and I appreciate it!

The cooler was pretty crusty underneath when I removed it but couldn't see any obvious signs of leaking on the body. Have you seen these fail before? I've attached some photos of mine when I had it out. I did clean it up before reinstalling it.
I'll get one ordered today and get it installed to eliminate it. It's a right pig of a job with the engine in situ, arms still covered in scratches 😂

There's what looks like a stainless steel line bolted to the top of the block as well, just next to the AOS and secured with 2 bolts. I couldn't find what this was or where it went to, could this be a suspect also or would that lead to same fault codes that you mentioned above?
 

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Yes i've seen oil coolers fail before .. from Boxsters to the 996 tiptronic ones on the box ... same basic item .

I like just about every garage would have a look .. unless there was a pretty obvious leak then we would replace to confirm ... or not , this being the defective item .

Basically we look the same as you !

The steel pipe .. that's probably the EGR pipe .. Exhaust Gas recirculation pipe and as such won't cause oil leaks .

I'll just point out .. oil coolers when failed .. that can cause oil in the coolant system .. brown sludge in the coolant reservoir .. it's not always a head gasket that causes this .. in fact the oil cooler if the first suspect .. not your issue though .
 
Bit of a slow update, between work and waiting on parts haven't got near the car.

Anyways, replaced the cooler, there's definitely no leak from the top of the engine now, but there is one coming from half way up the bellhousing now.

The month before I bought the car the clutch and flywheel were both done, they didn't change the RMS though. Could it possibly have gone throwing oil all around the bellhousing? Maybe my leak from above was the result of loads of oil having accumulated from up there?

Just contemplating removing the gearbox myself or paying someone to do it. I have ramps and a transmission jack, but have no way of supporting the engine, plus time is tight as well as going away again soon.

Also seem to have developed an idle issue, can't see any of the vacuum hoses off and can here air on the right hand side of engine somewhere, but not a clue where from.

Getting fed up now lol, maybe time to pay those who know better than I do, only problem is there's few here in NI I would trust enough other than the main dealer themselves who are very good.
 

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