squrlathon

Previously I wrote that after sending my 268 cams back to Eurospec they confirmed that there was nothing wrong with them -- at least that they were the same as the other set of cams they have in stock.

So while I was away recently, the mechanic had my car and couldn't make any progress in solving the noise issue, so he took it to the dealership where the shop foreman had a look at it. Apparently he thinks the noise is from the lifters...which is pretty much what the performance mechanic had said previously. The foreman said that since the lifters had been replaced (twice) that possibly they aren't getting enough oil, despite the fact that the oil pressure checked out okay.

I have been trying to make this point for a while. Since the noise is variable (sometimes it's louder than others) and since oil and oil pressure is dynamic, it seems logical that there is some relationship there. Meanwhile, everything else has been accounted for, with perhaps the exception of one thing.

Someone mentioned a short time ago in one of the posts that they had an exhaust manifold gasket leak (I believe it was a gasket leak) that sounded just like lifter noise. Now this would make some sense as the noise should get a little louder and faster with higher rpm's and increase as more air flows through the system and leaks out the leaking manifold gasket...also, it would make some sense that with the 268 cams allowing even more air through the system that the noise would get still louder (I'm not sure if it would get THAT much louder, but I think it's a plausible theory...). I'm only skeptical of this idea because two of the three mechanics believe that they have pinpointed the noise to be coming from the lifters or the immediate vicinity. It's difficult to argue with those findings.

So if it's the oil pressure, did the mechanic make a mistake when checking the oil pressure...? Or is it more likely that there is something else causing low pressure in the top of the engine?

Could the pressure limiting valve be responsible for this?

BigMouse

Was the noise present during the oil pressure test? Apparently, intermittent oil pump problems are common on VWs (heard second hand from friend who read it on VWvortex). Have you tried putting Marvel Mystery oil in? It worked on my NG engine.

greendoh

it actually does make a difference (at least it quieted my car down a bit).. I brought this bottle up from the states.. apparantly the formula is different here and there.. and the american one is the only one that is made for both gas and oil treatment..

MikTip

Ya need a direct pressure reading gauge for the oil pressure. You will need to attach the gauge, first near the oil pump, then watch the pressure at 1000 rpm intervals up to redline.

Then attach the oil pressure gauge on the head, as theres a small bolt on the back of the head, and repeat process.

Its possible the pressure fluctuates, at different rpms?

I'd also be curious as to whats in the bottom of the oil pan! ;o)

squrlathon

Okay, the mechanic put in an oil additive and I'll ask him what it's called -- that stuff didn't make any difference.

The mission now is to follow MikTip's advice and check the oil pressure using a direct pressure reading gauge at different parts of the engine at various rpm's and meanwhile listen to correlate any fluctuations with engine noise (ticking). Then if the oil pressure actually seems ok then I'll try some of the MMO.

Thanks guys.