pressure relief valve

[upallnight]

I bet if you were to use a thin metal rod you will see that the dry side has some blockage and that on the wet side the rod will go in deeper. You mention that you did have a sludge problem. Who know about German terminolgy, pressure limiting valve could be the same as a restrictor plug.

[audiqv8]

In all my experience, there is no dry side. Oil is always circulating beneath the cam cover. In fact many of the valve covers have baffle to limit the splashing of oil. Think about it, if there was a "dry side" then why would they bother with valve cover gaskets?

[upallnight]

Don't drive the car or you could do serious damage to the engine.

http://forums.audiworld.com/showpost...2&postcount=26

[upallnight]

Originally Posted by A6Gary

Per ETKA, they are called "pressure limiting valves", P/N 078–103–363–P, one in each head (AFC engine). There are also the (2) "check valves" underneath the intake manifold in the valley.

That is correct, they limit the oil pressure for the hydraulic lifters, so that the pressure is always constant. So in order for the valve to work correctly, they need to "Bleed off" excess pressure. So seeing oil there means the valve is working correctly, not seeing oil there means the valve is not working correctly.

[egp320i]

The noisy side was the same when I took the VC off and the lifters had plenty of oil on them. I even watched the engine run with the cover off and plenty of oil was where it needed to be.
One of the lifters is not plumping up and the gap is too far so instead of the lobe just rolling smoothly it is more like hitting.
Both are very hard rockwell steel so besides being annoying most likely no damage.

That said I have put some 8K on it since, runs smooth, has great power but a bit tappy.

I was running a few shots of ATF the past 5K to see if it would give a little extra scrub to clean up sludge but it really did not help at all.

When I get a chance I am going to take the cover off again and see what the deal is.

[upallnight]

Originally Posted by egp320i

The noisy side was the same when I took the VC off and the lifters had plenty of oil on them. I even watched the engine run with the cover off and plenty of oil was where it needed to be.
One of the lifters is not plumping up and the gap is too far so instead of the lobe just rolling smoothly it is more like hitting.
Both are very hard rockwell steel so besides being annoying most likely no damage.

That said I have put some 8K on it since, runs smooth, has great power but a bit tappy.

I was running a few shots of ATF the past 5K to see if it would give a little extra scrub to clean up sludge but it really did not help at all.

When I get a chance I am going to take the cover off again and see what the deal is.

Could be that one of oil passageway in that cylinder is clogged so that the tappet does not receive an adequate supply of oil hence the enormous gap between the cam and tappet or you could just have a bad tappet.

Here's some additional info on hydraulic lifters and their disadvantage.

http://en.wikipedia.org/wiki/Hydraulic_tappet

[Prospeeder]

lifters are pretty cheap. toss a set in. theres only 12, lol. Im going to buy new ones for mine. Im going to pull the heads and do a full reseal.

[egp320i]

They are roughly 12 bucks each at AZ for OEM INA. Price is not the issue, it is removing the timing parts and the camshaft which is time consuming especially when said vehicle is usually in use.

I have the cam bar and plug, just have to make sure the cam goes back in the same plus once you disturb the cam you really should replace the front cam seals.

If sludge is the issue replacing the lifters will not help the matter, the engine just needs a heavy douching of kerosene based engine cleaners.