What's going on here? (oil leak)

[snakeye]

So the top of my engine was a complete oily mess, so I pressure washed it, and found these first oil spots soon after.



Is this the ASV shooting oil out? Can it actually do that without also having a boost leak?The oil cap seal was already replaced, and this doesn't seem to be coming from the valve cover, which I also opened and re-torqued recently. Any ideas? This seems to be a recurring problem on all the ALH TDIs that I drive.

 

[Tdipwr11]

Yeah, that rubber that's around your oil fill cap catches oil spill. It's most likely leaking out of there, down. Take it off, wipe it all with a rag and see what happens

 

[03TDICommuter]

It's likely your EGR valve. There's a vent port and will start spewing oil when the seal fails between the shaft and the intake side of the valve.

Edit: absolutely your EGR valve - you can see it messier there.

Dave

 

[csstevej]

Yep what 03 said , I had the same issue , I’ve tuned the egr out but kept it for the ASV and sealed up those holes when it started to leak on mine.

 

[Fahrvegnugen]

I had that too and just bought a new one from idparts. It didn’t throw a boost code. New one doesn’t leak

 

[oilhammer]

Pretty common issue, oil in the charge air tract from normal crankcase scavenging gets pushed up the EGR valve shaft that has a worn bushing and past the internals and out that vent hole.

 

[snakeye]

Vent hole, huh... Maybe I'll just attach a tube and direct that oil somewhere where it won't make a mess. It seems to be working fine otherwise.

 

[oilhammer]

Or try one of GM's tricks they used on the Quad-4 and its variants' water pump weep hole: wrap it with a maxi-pad.

 

[snakeye]

Or try one of GM's tricks they used on the Quad-4 and its variants' water pump weep hole: wrap it with a maxi-pad.

That's an odd fix; was there a tsb for that? I would do it, but it would require monthly changes, and would end up being more costly than a mere tube.

 

[oilhammer]

May have been a TSB, but those were issued a little less frequently back then. These were the GM DOHC and SOHC engines, the DOHC came first, and was known as the Quad 4... later a SOHC version came out. Both were initially 2.3L, then later the SOHC was dropped and replaced with the 2.2L Ecotec engine from Opel/Saab, and the DOHC version got bumped up to 2.4L and they dropped the Quad 4 name and just put 'Twin Cam' on the engine instead.

The water pump on those engines was driven off the back side of the timing chain, underneath the exhaust manifold, which had to be removed for access. The 2.3L versions allowed the chain to stay in place, as the pump slid out the back side of the timing case, the chain driven gear was splined and stayed in place. The later 2.4L versions were all one piece, so when the water pump died, you had to take the chain drive all apart. And if the water pump failed and the driver kept going, the chain would jump and bend all the valves.

Anyway, because the water pump was so labor intensive, and they often had a small weep from the weep hole that was no real cause for concern but made a lot of unnecessary warranty claims, they came up with this little plastic band that clipped around the water pump housing. And a little slot in that bad was full of a strip of absorbent material, that lined up with the weep hole.

This captured and slowed down any weepage. Got them out of warranty.