[br_318_d]

Hello everyone,
I would like to ask for help if anyone has experience.
I have had a problem with my X1 xDrive18d automatic for a long time.
After mapping the engine to 140kw power, a sound can be heard from the rear part of the vehicle, around the rear differential and towards the left wheel.
The sound is heard as a metallic knock only when accelerating from a standstill, it is not heard when stopping or driving or when changing gears.
The mechanic tried everything, I changed the flex disc, the left half-axle, the rear brake pads, checked the suspension, the rear frame .... everything OK.
Has anyone had experience with a broken diff or similar?
Please some advice or help

[jcreme]

I have found the F48 to be extremely sensitive to suspension changes and generates loud banging noises when suspension components are worn.

I had a loud noise in the front, disassembled the suspension, and replaced identified worn parts. The noise persisted. I ended up replacing front suspension parts one by one until they were all new.

My point is this: a typical suspension inspection (moving the suspension around looking for incorrect movement) and even inspecting disassembled parts did not reveal any parts that should be replaced. But they needed to be replaced. The tolerances on this vehicle are unusually small.

I suggest replacing suspension parts based on mileage not by inspection.

By the way, I have not found the same for engine/transaxle/differential mounts which seem to be extremely forgiving.

[br_318_d]

Thank you for your reply.
I'm putting on new tires soon, so I'll tell the mechanic to check everything in detail again.