Taping/Knocking Noise! Foreign Objects in Oil Pump!

[zak 0]

no idea on the residue on your piston crowns but congrats on doing the work yourself.

[Kevin Bacon 5]

The black crud is carbon build up. A mixture of oil and burnt fuel deposits, perfectly normal. How did the step from the crud to shiney bore feel? Was it deep?

 

Yellow crap could be fuel. I had orange piston crowns after using Optimax + an octane booster.

 

Looks like a typical VR to me, don't think there's anything significantly wrong there chap.

[iceviolet 0]

Yes there was a bit of a step from crud to bore, could feel it quite well when i ran my finger over it. What does this indicate? I cleaned it up anyhow.

I use the super unleaded 99 octane from tesco all the time so could this be producing the yellow deposits??

 

Well ive done quite a bit of work under the bonnet on the corrado now since i bought it, so im going to concentrate on the bodywork and suspension next. Rear beam next on the list, as the road noise has returned after just a couple thousand miles on new tyres. Aswell as continuing with my vr6 rebuild in the garage, want to keep the 12V VR6 alive.

[Philmo 0]

Just spotted this thread!

I had a knocking/thumping noise, started after Vince refurbed CH, and put 263's in. The source seemed to be the blower gearbox and the thump was worst from cold, dissipating to nothing when fully warm. A clear thump could be felt as well as an audible knock - v disconcerting as I thought the blower might be faulty or at risk.

Frequency was approx 6th of crank speed so I put it down as related to the 7 rib belt drive.

Sure enough when swapped with my standard weight spare belt the knock disappeared forever. :D

Vince had fitted a heavyweight belt which seemed to take up a fairly rigid static shape when cold and then took some warming up to flex it up a bit. Side by side the belts are quite different in flexibility but only a little different in cross section.

[Kevin Bacon 5]

Yep, ditto!

 

Mine made some disconcerting clattering noises when hot, which sounded just like worn out tappets. Vince told me to change the belt, as bizarre as it may sound, and sure enough it's been silent ever since. It must have been your car he got that weird fix from!!

 

Incidentally, I changed from a cheap pattern belt to a genuine one and the noise went completely.

[Philmo 0]

Yep, ditto!

 

Mine made some disconcerting clattering noises when hot, which sounded just like worn out tappets. Vince told me to change the belt, as bizarre as it may sound, and sure enough it's been silent ever since. It must have been your car he got that weird fix from!!

 

Incidentally, I changed from a cheap pattern belt to a genuine one and the noise went completely.

 

Shsh! I haven't told Vince yet! :ignore:

[There are a couple of improvements/developments to mention next time I'm down there!]

Not sure as to the origins of the silent belt - it came, un-used, from one of Karl's clear-outs - cheers Karl! :wave: