New 996 possible oil leak, picture attached

[rasank]

Hello All,

I just bought a 2001 Carrera, PPI was done and apart from leaking spark plug tubes and an oxygen sensor that needs to be replaced, it's a great car. Beautiful condition with about 35k miles.

I did an oil change and after a little driving I was poking around and noticed a patch of oil that I didn't see before. It's behind the throttle body where it branches off towards the intake manifolds (pardon the non-technical newbie description). I have attached a picture with arrows indicating the spots. The hose clamp has some oil and the tube below it has some too. What could this be?

Thanks for you help!

[logray]

Hello!

Could be oil vapor coming from the AOS tube going into the plenum behind the throttle body. That tube has an o-ring, but it wouldn't be a lot of oil leaking unless your air oil separator is bad..

Could be a leak in the oil fill tube itself, as they are prone to such leaks and cracking as they get old.

Best thing is to clean the surrounding area, then keep an eye out where the leak originates from.

Hope this helps.

[wvicary]

Be sure the hose clamps are tight,wash the area off and monitor.

[rasank]

Thanks for the replies! Logray, the filler tube seems clean. I will tighten up that clamp, clean up the area and monitor it. I don't remember seeing it until after the oil change (previous owner has been putting Mobil 1 0W40, I changed to Motul Xclean 5W40).

[goldenwarrior1]

1. Looks to me like it is leaking from the intake crossovers. If you had a bad or going bad AOS you could have a lot of oil in the intake plenum and it would seep out where the large worm clamps attach. Pull the oil cap while the engine is running and see if it has excessive vacuum. If so, that is an indicator of a failing AOS.
   

[rasank]

I was able to pull off the oil cap easily. Took it to the shop recently for the 30k mile service and they said it wasn't anything to worry about. According to them, a little oil smear is normal because there is always some oil in that comes out into the intake plenum. Who knows, but I have cleaned out everything, we'll wait and see how much appears.