VW Passat TDI: 1Z Engine Valve Noise/Rattling

Hello everyone,

'In my Passat TDI, 1Z, manufactured in 1996 (235,000 km), the valves are making a rattling noise. I have already replaced the camshaft and the hydraulic lifters, but the noise persists. I suspect that the valve guides in the cylinder head, where the hydraulic lifters are located, are worn out. This would explain why the rattling noise is still present even after replacing the lifters. However, according to a mechanic, this should not be possible.'
Does anyone have any other tips for me?

The valve guides could very well be the problem. They wear out eventually as well. If the oil pressure is correct and it's actually coming from the cylinder head, I would first check the injectors (or have them checked) and then check the valve guides for play.

Okay, I'll remove the nozzles now and take them for testing.

'I also experienced this problem with my AFN engine after 250,000 km! I replaced the hydraulic lifters, but it didn't result in a significant improvement. I then installed a replacement cylinder head, and since then, everything has been quiet. I'm now at 327,000 km, so 77,000 km with the other cylinder head, which I bought as a complete exchange unit for 250 euros (a new part).'

The valves have been tested and found to be in good condition. Next, I will measure the valve guides for the hydraulic lifters.