Hello.
Today i heard a new sound coming from the car. It sounds like knocking but you can only hear it when the engine reaches 2k rpm and only from 3rd to 5th gears. When stoped and in neutral there is no sound coming above 2k rpm, only when driving. The knocking sound goes away at about 3k rpms. What that sound could be?

Lexus is220d 2007.

 

All diesels are manual? You can try uploading the clip of the sound, but I'm afraid not many people here will be able to help you, as most seem to drive the autos. This is everything the "220d knocking" search yields: https://www.clublexus.com/forums/is-...d-in-gear.html. I would try searching the net for generic manual transmission issues. That said, knocks happen for all sort of reasons, and may not even be transmission related at all. If I were adamant at troubleshooting this myself, I would first try to exactly pin-point the origin of the sound, which might be tricky if it only manifests while diving. You can use these type of tools for this: . Good luck...