Engine Noise: Loud Rumble from 3500 RPM

hi
'I have a new problem. My car is making a very loud noise above 3500 RPM, which wasn't the case a few months ago. I have a Passat 35i with an AFN engine. I was thinking about changing the oil because the last one was done in the spring. Do you think that might help?'
Okay, Chris. Thanks.

Hello!

It's possible that your engine isn't properly seated in the engine mounts, which could be transmitting vibrations to the chassis. If you loosen the engine mounts, start the engine briefly to allow it to settle, and then re-tighten the mounts, the problem might disappear.
Another option would be to install the flexible pipe before the catalytic converter, as those often break and can transmit vibrations to the exhaust system.
I had a similar problem with a Golf 3 diesel (47kW), and it turned out that the tensioner for the alternator belt was broken. I replaced it, and the problem disappeared!

Just try it!

Best regards,

Tim.