ocran

Hello Rennlist,

I've got a small coolant leak on the passenger side of the engine that is driving me nuts. I've got dampness around the lower bellhouse junction with small drips in the surrounding area. All drips are along the centerline and passenger side of the car. There is dampness on the passenger side head as well, and if the car sits for long enough coolant will propagate and drip from the forward most(car direction) header stud. Although, primary drippings are from bellhouse junction and surrounding area. There are no drips further back than the previously mentioned header stud.

I originally thought it was the coolant casting port on the passenger side head, but that was not the case. Although, if you are familiar with the layout that area is still damp. The gasket has sense been replaced.

After doing some research it looks like the oil cooler may be the culprit. However I have heard some mention that the AOS can leak as well.

I've had the car up on stands on two different occasions trying to diagnose the source but I can't seem to see anything.

Any ideas?

fpb111

What year/model? If a Turbo could be one of the coolant fittings.
The AOS is on the left side. The cooler is more right of center.

kromdom

have a pressure test done to help you locate/pinpoint the source of the leak. best of luck.

ocran

It is a 2002 C4S.

I've done a poor man's pressure test which was in inconclusive; it will hold coolant pressure for days, yet still drips on the floor.

Thanks for the feedback, I'll look more closely at the oil cooler considering it may be the only plumping in that area.

Ahsai

Don't waste time on anything else. You need a proper pressure tester that keeps the system pressurized at 18PSIG for at least 20 min if not more.

targa996

I had coolant staining near oil cooler - but never noticed a leak. When I did ims/rms - I had indie look at oil cooler coolant hose connections - o-ring degrades over time and I think more than one person on the board here has also had to do this. Indie replaced o-ring and fixed the problem. Anyone dropping trans to do ims or aos should replace oil cooler o-rings on 10+ year old car as preventative "while you are in there"

318touring

Which one is the oil ring, 35 x 4 or 26 x 3?

Pelican Parts

targa996

Good question - I also looked it up on the porsche parts diagram - one ring is for coolant and line and other for oil line - not sure which is which - Id replace all - probably 2 of each - (inut pipes) - cheap insurance