kary993

Some history first. I have had a small oil leak appear on the floor just off center to the left side of the car toward the rear of the motor. It was very close the center of the engine in the rear but still to the left side. I do not have the underneath cover on so I can see the leak (drip point), otherwise I would have never known it was there other than I could smell the oil when the engine was hot. The leak started about 1 month ago and comes and goes. At first I thought is was related to how often I drove the car. The longer it sat then the oil would appear, but lately it has not been leaking no matter how often the car is driven.

Since I purchased the cup suspension, my shop was putting it on and noticed a leak in the strangest place. It seems to be coming from the flapper value for the varioram that is mounted above the fan cover and attached to the intake manifold. You cannot see this value very easily if at all when everything is in place so they took off the fan shroud to see where it might be coming from. The oil seems to be coming from the value and dripping down the fan shroud to the left side of the engine, pooling slightly at the flat part of the engine at the rear and then slowly leaks down below ultimately to the ground. The leak is maybe 10 drops over a week period.

The shop is a bit stumped as to how oil could be leaking from a air intake valve device. They tested the cylinders doing a leak down test and everything was good. They thought is might have been "blow by", but since the compression is good seems like it might not be that.

So we decided to clean the oil up and watch it closely after running the car hard to see if we can pinpoint the actual location of the oil leak. After the suspension is completed we will do that test, probably early next week.

Anyone seen such a leak form this value before?

Thanks for the help.

ppressle

Hi all,

I think I am seeing something similar. About a year ago, I noticed some oil film under my varioram, on the top of the engine. I spent the better part of a day cleaning it all off.
Now, a year later I see that it is back. I can see a trail leading up to the varioram valve...

Any ideas on what is causing this and how to fix it? The intake should not have oil in it.
I am pretty religious about keeping the oil around the half way mark on the dipstick.

Thanks for any ideas.
Pete

viperbob

2 things there are very common for leaking, esepecially cars that do a lot of track time and build a lot of crankcase pressure. There is the main breather (back center of the engine aluminum cover with black hose coming out towards the passenger side), and the oil pressure sending unit right next to it on the passenger side. I had these go bad on my turbo. PAIN to fix (step 1, remove intake with throttle bodies). 99% sure that one of these is causing the problem. Whichever is leaking, replace the gaskets on both of them. Both of these started leaking within a couple months of each other. I had already fixed the one gasket, then I had to remove everything again to fix the second one....

Flying Finn

+1 what Bib said, when I read you describtion, first thing that came to my mind was the oil pressure sender.

geolab

One small detail though,,,
on the 1998 carrera S engine, the pressure sender is on the short-engine, down on the block with the oil temp. sending unit. so this could not be it.
Unlike the precedent engine version (up front) and the turbo (up rear left).
However, I totally agree with VB about the oil pressure breather (wastegate) that should
loop to the inlet,
Another reason for condensated oil return fumes is doing the italian VROUM in the parking, and
before the rpm settles down, turning the ignition key off after a ride.

viperbob

This point on right half case on the top towards the firewall is exactly one of the items that I am saying can be the issue. There is an aluminum cover (993 101 768 01) that has a o-ring on it. Also the seal rings for the temp sensor and pressure sending unit (or fitting for the '95 NA and turbos) can be problematic. Nothing unique about the '98. Also that that upper rear left sending unit on the turbos is for the boost pressure, not oil pressure. Looks similar though.

ppressle

Thanks guys. I'll print out your comments and go look at the engine to see what I can figure out.

I am definitely seeing weeping on the underside of the manifold around the varioram actuator valve. I also see a corresponding spot under it on the plastic fan housing where it looks like oil has dripped from the actuator valve on the manifold. It is also a very very slow leak. About a year for the top of the engine to get oily. (4k miles?)

I'll clean it up and see if it is coming from the breather or oil pressure area, but I suspect not.

I'll check your suggestions, but any ideas why the manifold actuator might be dripping oil?

Thanks.

vanHunks

Is it not the oil-vapour from the crankcase being recycled into the inlet manifold ? My specialist suggested (if I'm quoting him correctly) additionally that if the air-filter element is partially blocked this may also be instrumental in pulling excess vapour up from the crankcase.

vanHunks

I removed the "flapper valve" - terminology ? Part # is 992 110 061 03 - from the bottom of the Varioram. It was thoroughly gunked up with oil and muck. Cleaned it out. The steel shaft of the flapper turns in a brass bush pressed into the bracket. There was a lot of play in the shaft/bush - the displacement at the top end of the flapper shaft was 1-2 mm. Is this normal ?