Loud ZR tensioner

Hello experts,

Unfortunately, there are some problems with my daughter's Golf.
After a ZKD (cylinder head gasket) repair on a Golf IV (85kW-PD engine, 127,000 km), a running noise can be heard for a few minutes when the engine is cold. I know, it's hard to describe , it's more of a whimper - very quiet at idle, getting louder as the RPM increases, and around 2500 RPM it gets masked by the engine noise.
The technician (from Bosch service) listened to the tensioner pulley and said it was defective. The frustrating thing is that the timing belt was only replaced 16,000 km ago, so they reused the old parts. The noise was not present before the repair.
I'm bothered by the fact that you can only hear the tensioner after a few minutes. Speculation: The belt tension is too high, and the bearings only start making noise when the grease filling is very hot.

Does anyone know if it's possible to make a mistake when tightening the roller?

At this point, I'd also like to express my sincere gratitude to everyone who has written about ZKD repairs in this forum. I've learned a lot, including from Rainer et.al. about air bubbles in the return line, and from Michael about defective [something - the original text is incomplete]. Compensation tank and ...!

Best regards.

Helmut.

Helmut wrote:

Does anyone know if there's something you can do wrong when tightening the reel?

Hi Helmut,

Sure: You can tighten them too much, too little, or just right. If you do it carefully, nothing should go wrong. Are you sure that the tensioner pulley is meant? There are several other possible causes for such noises (ribbed belt, alternator bearing, etc.).

Hello Helmut,

It's good that you're worried; you should be. If the roller breaks, it will destroy your engine!

So, definitely don't skimp on the ZR drive – if there's any suspicion about it, get rid of it immediately.

What you can do: Push the roller away from the edge so far that you can turn it by hand. If you notice anything unusual or if it starts making noises, it's time to take action.

Hi,

I had the tensioner replaced today. I've agreed with the workshop to pay 50% of the labor costs.
Agreed. The role is guaranteed. VW only accepts the labor time if it was performed in a VAG workshop.
The cause of the cylinder head damage, incidentally, was the failure of the radiator fan. It happens quite a few times.
It can get pretty hot when the young ones are speeding along the highway.

Thank you very much for the answers.

Helmut.