clinchy993

Ok guys I did an extensive cam cover /timing chain cover re-seal about a month ago and all are bone dry but on the journey down to Spa with the London 964 gang the car started to drop oil again

So I left my car on a ramp in our workshop last night after cleaning the engine with some brake cleaner and running engine for a while

Over night and to day a fine film of oil has appeared again and its coming from the top rear of the engine where the oil breather pipe and pressure switch is ,not lots but enough to pool a few drops and enough that once on the move it will coat that whole bottom of the engine

So has any one replaced the gasket and seals by removing the Air intake filter and heater blower and without taking the inlet manifold off
This Iphone pic is looking up from the gearbox towards the engine tin wear at the rear of the engine



My lovely clean oil is all over the crankcase both sides as its running down between each cylinder

boxsey911

Tony, the seal on the oil pressure sender and the vertical oil breather pipe next to it are well known for causing leaks on top of the engine. To access them you're best to remove the inlet manifolds. Not a hard job. Just a bit time consuming. This DIY gives lots of info:

https://rennlist.com/forums/964-1989...-cleaning.html

There are plenty more threads on here but the search function seems to be down at the moment so I don't have any links for you.

These photos on my blog might help too:

http://boxsey.blogspot.co.uk/2009/11...ak-mar-08.html

clinchy993

Cheers Steve

I know what I will be going next week LOL

BigMikeATL

Just did this job but I had the entire intake off. With that said, removing the right side intake is really easy. It well worth the effort because it will probably take less time to remove the manifold than to replace that o-ring with the manifold in place.

clinchy993

Cheers Mike I was going to start it today but I have a raging hangover

clinchy993

Another leak cured

Whipped off the air filter and the offside air intakes (very easy) thanks Boxsey for the guidence

This made it very accessible to remove the oil pressure sender unit and replace the large rubber O ring ,the original was brittle and fell apart as soon as I touched it

Also there is a large breather return pipe that was moist at the bottom I pulled on it and it came off with no effort despite having a jubilee clip on it although this one was different design to all the others so I replaced it

Sorry for the pics ,it was a quite difficult to get clear photos in there

Does any one know why there was so much oil in the where the butterfly valve is in mine and Boxey's photos it it from overfills ?


some pics

Back of the airfilter box


Offside air intakes



Oil pressure sender unit with new O ring





The central core of the air intake system ( note oil in lower one with butterfly valve )









Right whats next :?:

Rocket Rob

Congrats! Hope that solves your problem.

911Jetta

My O-ring was shot and caused the car to leak also. Wow was I surprised when I saw my old O-ring, all shrunken and skinny. I didn't find much evidence of a prior oil over-fill, but it felt good to clean (and paint) the intake while I was in there.

BTW, it was my first time doing much dis-assembly to the engine compartment... so even a rookie can do this repair. dfinnegan's (Dave) thread above made it possible for me to dive in.

pi5tolpete

With the oil pressure sender unit on the RHS of the engine, could it contribute to a visible leak of oil on the LHS, or are my worst fears correct and that I have to do a valve cover gasket job?
Pleaseohpleaseohplease let the sender contribute to a leak on the LHS. (?)

Rocket Rob

Anything is possible but I would not expect the oil pressure sender to cause leaks on the left hand side. Changing a valve cover gasket is not too hard, just time consuming. When was the last time your adjusted your valves? Maybe you can do both at the same time.