Oil Non-Return Valve Failure !!! ???

[SNice]

In the middle of an engine “refresh”. Going waaaayyyy deeper than I intended….
In short, I ended up taking apart the head.

I pulled the brass colored check valve out of the head. Top left corner of this picture:
IMG_1093.jpg

This is the “oil non return valve” - 06H103175B I was going to replace it anyway, but I was shocked at what I found upon inspection:
IMG_1097.jpg
IMG_1098.jpg
IMG_1099.jpg
The backside is completely blown out. There is definitely metal missing. Was this a “catastrophic” engine failure waiting to happen?

My cam bridge screen was also missing and I found it by the screen at the fuel pump.
IMG_0881.jpg
There were also some little pieces of metal. I thought they were screen bits but maybe they were from the oil non return valve.

I’ve been looking for info on this failure. I found this:
https://ssch.com.au/bulletin-vw-audi...-return-valve/
And this:
https://www.vwwatercooled.com.au/for...ve-133999.html

I’m thinking I caught this before the “worst” could happen. I’ve ordered the replacement but it seems like eventually it will happen again. Curious if anyone has more info on this? Also a heads up as this could be related to oil flow problems in the head.


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[Theiceman]

it's a check valve.. if it fails in open state, not a big deal.. may be noisy on engine start from oil draining back into the sump as it builds pressure back up.. obviously since most engine wear happens in start up, not a good thing but not catastrophic.
if it gets stuck in closed position or starvation you will rob the cams of oil as well as the vvt system. symptoms are usually p0016 codes first and " "slow cam" response codes"

seen it a few times...it sucks when it fails closed. a lot of work for a freakin check valve

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[Allowencer]

Find bits of screens in the HPFP screen is common. That could hurt oil flow to the HPFP which can cause premature wear on the follower and lead to other issues.

Hah, I was just about to post and tag you @Theiceman . This is why I've said before it should be changed. Check valves go bad over time. Do you want to take the chance if it will fail open or fail closed, or somewhere in between?

Even failing open can cause other issues to where it is not a restrictive point in oil flow that is intended to be there and you might drop/lose oil pressure overall in the circuit; especially in the top end.

If you're removing the head, swap this!!! For Christ's sakes, it's a pull out, push in. If it takes you longer than 5 mins, you're doing it wrong! Lol

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[Allowencer]

Hey @cybernet99 - the symptoms in the one article that describes this issue sound awfully close to what you shared with me. Something to look into for sure. Maybe it isn't your cam setup?

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[Theiceman]

and of course I didn't change it lol...

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