HELP: E87 118i A/T Slight Grind

[e46er]

So, after an unfortunate incident where the criminal elements placed a rock in the middle of a lane, I find myself hearing strange sounds from my car.

After hitting the rock at 130km/h, the car broke down further up the road. All of the engine oil leaked out and the gear was stuck in drive.

After towing the car to my local BMW mech and some assessment, the sump had broken, and the gearbox sump had a dent and a hairline crack. In addition, the subframe had also bent.

After replacing these parts, the car makes a weird grind noise until about 3000rpm. The gearshifts are also not as smooth as they used to be.

What could this be?

Apologies if this is posted in the wrong section.

 

[Kyle]

OK but seriously, this may be a sign of debris left internally.... Does it only make the noise while driving or stationary as well? Perhaps try revving the car in neutral to test.

If it does not make the noise then it would be something in the gearbox...

 

[e46er]

OK but seriously, this may be a sign of debris left internally.... Does it only make the noise while driving or stationary as well? Perhaps try revving the car in neutral to test.

If it does not make the noise then it would be something in the gearbox...

It's when driving. At idle its subtle.

 

[Kyle]

OK but seriously, this may be a sign of debris left internally.... Does it only make the noise while driving or stationary as well? Perhaps try revving the car in neutral to test.

If it does not make the noise then it would be something in the gearbox...

It's when driving. At idle its subtle.

What happens when you rev the car in neutral or park? Is the noise evident?

Also what oil was used to fill the gearbox?

 

[e46er]

OK but seriously, this may be a sign of debris left internally.... Does it only make the noise while driving or stationary as well? Perhaps try revving the car in neutral to test.

If it does not make the noise then it would be something in the gearbox...

It's when driving. At idle its subtle.

What happens when you rev the car in neutral or park? Is the noise evident?

Also what oil was used to fill the gearbox?

So when revving in neutral or park, the sound is not evident. It's only when moving and ony up until about 3000rpm.

I'm not sure what oil was used. I did however add some ATF the first day after getting the car back.

 

[Kyle]

More than likely an issue with the gearbox then. How did you add ATF?

These boxes require a specific spec of ATF so just make sure the correct fluids were used, was the gearbox filter also replaced?