996dougie

Hi all,

before taking the decision to drop the engine, I thought it might be helpful getting a second opinion.

Problem: about a year ago I got a 996 GT3 with a bit of missing maitenance. I renewed Cluch, Flywheel, release bearing, all whishbones and so on.
Remaining problem: its loosing oil ... depending how you drive quite a lot.

Leaving the car stationary with running engine up to temperature: no problem.
Driving around with low rpm (e.g. inner city): no problem
Driving on the highway 3rd, 4th, 5th gear up to 7000rpm: loosing lots of oil on the left engine side. Theres a blue cloud behind me from Oil running over the exhaust manifold.

I'm almost certain that it's not the oil circuit itself or the retun lines to the tank

My current guess is that it must be related to the crankcase ventilation...

What do you guys think? Any other option than taking the engine out?

Marv

The old fashion way to do this is to scrub everything clean and inspect after a short drive. If you can't see it, then you could add a dye to the oil.

Keep in mind that high speed driving will cause the oil to migrate with the airflow, so it can be misleading.

I would start with not driving it on the highway and inspect. With a clean engine it is much easier to see the true source. Also, a cheap bore scope helps you see places that your eyes and mirrors can't.

996dougie

Thanks mate, but I tried that already ... engine had been cleaned and inspected while it was running in the workshop without a sign of leakage. But as I said: it seems related with high revs.

And with the amount of oil coming down the Engine, it's hard to find the source. Does somebody have a picture of the left side of the engine. Preferrably from the front where the gearbox is attached?

Marv

What is the oil level in the engine now?

Use the indicator on the dash, not the dip stick.

powdrhound

Put on up on the lift, clean everything, and them run the car on the lift. Take the rpms to 7500 or so and hold them there for a minute of two so you have high oil pressure which will propagate any leaks. Get a boroscope which will allow you to see in hard to reach places around the engine.

996dougie

996dougie

....after a weekend of sleep and following this thread : https://rennlist.com/forums/996-turb...-oil-leak.html

I came to the belief, that it might be something related to the Oil console.

Question: is this really an engine-out-job or can this be done without too much trouble after just removing the intake manifolds?

BR
Ralf

AudiOn19s

Could be broken tab on the oil cooler that's caused the base to come lose and leak...or some other random issue with the oil cooler up there.

Could be the supply / return line to the external oil tank..mine leaked where the flexible rubber section comes together with the metal line

I'd be really surprised it it was rear main with that much oil all over the place.

If you're really good at working in tight spaces you can take the center of the intake out and the upper intake tubes and probably get back in there to better identify where it's coming from but the work will be painful and tedious at best. Pulling the motor seems daunting but it's honestly the easiest way to work on these things when you're focused on work up in that area.

996dougie

Thanks a lot for the info, Andy.

In this case I will take Engine and Gearbox out.... in another thread it was said that taking out the gearbox without the engine is more hassle than taking the whole assembly out.
I did replace the Rear Main Seal, Flywheel, Clutch and Release Bearing few weeks ago myself, so I think I might be prepared for this task as well.

theprf

I don't know how far you have gotten with this. I am the original poster of that linked thread. That leak ended up being perished O rings, not the welch plug.
Later I had another gigantic leak. That one was the breather hose from the oil cooler console to the oil tank that's shaped like a "?" had split. At high rpm it would spray oil everywhere.
The thread:
https://rennlist.com/forums/996-turbo-forum/1308761-split-oil-vent-hose-at-oil-tank.html

996dougie

Thanks so much for taking care!!
My lift is currently occupied by my other car (a Lotus Elise) for an engine swap.

So I took the GT3 to my favourite garage this friday for tankinbg the engine our and have the oil console inspected.
I would bet some $ that the problem is related in that area.

I'll report as soon more info becomes available.

BR
Ralf


Edit: But I have to admit that this looks pretty similar to my engine symptoms so far...