Oil leak near AOS

[djnolan]

The latest good news is an oil leak near the AOS, flowing down a little to the left of the AOS. Is anyone familiar with the leak shown, and is it the AOS seals or something else? Thanks!

[dgcantrell]

Could be. There is another o-ring seal in the housing at the top near the head/block mating surface. You really should just pull the intake and inspect all the seals in that area. Mine was leaking from under the cam tower between 3 and 4 ever so slightly a while back. I had to replace the gasket (and a few other items) and replaced the o-rings on the separator housing while had it apart. While I had the cam tower off, I did a little custom painting.


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All buttoned up....


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[mytrplseven]

Bottom line, is there's potential leak places in that area. The back of the balance shaft housings, the AOS seals, the dip stick seal. The balance shaft housing can be sealed with a coating of permetex blue or silicone sealer (clean area with acetone first), the AOS seals need to have the intake manifold removed first (no crying) and the dipstick seal is a quick, no brainer. The good thing about the AOS is that if they're leaking, they can cause an ingestion of oil into the intake and while the manifold is off, you have access to vacuum hose connections, and other hidden sensors and hoses you can't normally get to.

[dgcantrell]

I think it would have to be coming from up higher on the engine to pool in that area between those two casting webs. Fortunately, on the non-S/S2 normally aspirated 944's, removing the intake is not that big a task to undertake. I kind of dread pulling the intake off the 944S I recently acquired. Somebody painted the intake and valve cover (easy part) a god-awful purple-blue. The car is silver but I think I may go red with the valve cover and silver with the intake. Why Porsche used tan on these parts is mystery to me. Tan? Really? In the engine bay? LOL

[djnolan]

If it is the balance shaft housing seals, do the balance shaft pulley and the inner front cover need to be removed to reseal it?

[djnolan]

At this stage RTV'ing the end plug from the outside without further disassembly is my best hope. It looks like it can be done in less than an hour on the left side. I think/hope this is where the leak is.

Oil leak repairs-anyone relate to this picture?

[dgcantrell]

Actually, the front seal for the balance shafts are mounted inside a separate piece than the cover so you can remove the cover and and not have to undo the balance shaft belt or the timing covers for that matter. You will have to remove the intake though. Here is a good video showing them before assembly.

https://www.youtube.com/watch?v=QekGLvys3z4