Noisy variable cam.

[Trotts]

Hi, recently bought a broken Mk6 GTI. Bent inlet valve. Anyway head off and new valves installed and complete Head service. New chains, guides and tensioners. All back together and runs nicely no codes. Except for a horrible rattle coming from the variable cam timing mechanism on the inlet cam. Most apparent when the engine is at normal temp and at idle. I have used a stethoscope (screwdriver) and the noise is definitely coming from that mechanism. The camshaft I used was a SH unit with 200+k on it. The original marked by displaced lifters. I have thought if perhaps the vanes in the mechanism have worn but also was told it could be the oil non-return valve. Suggestions Thanks in advance

[h100vw]

The cam bridge that supports the ends of the cams. make sure the filter is removed. They break up and do damage, being metal.

Check the cam bridge isn't scored on the inside allowing a loss of oil pressure to the cam adjuster. I had one recently, ran great from cold, high oil pressure. Wouldn't start well when hot, the cam timing was way out as the adjuster had all the oil squeezed out of it.

Another recent failure was the non return valve in a second GTI getting jammed closed. It starved the head of oil and ruined the cam journals and cams. That turned into a new head and some secondhand cams.