[harisb]

Brought my E91 LCI N47 Automatic to have the timing chains swapped out (additionally swapped all 4 glow plugs as one of them was throwing a code) and until that point all was good.

Received the car back and now when doing hard accelerations with a full pedal the car is shuddering. This doesn't happen when going from 0, it starts on 3rd gear around 1.8k - 2.4k RPM. If I let it rip after that it doesn't shudder anymore. The car pulls well, gears shifts well. Vibration is constant in that RPM range, doesn't seem to correlate with speed. If I don't slam the accelerator, the shudder isn't that prominent. No codes, nothing.

Mechanic that swapped the chains said he checked his work and found no issues, but I don't know how closely he looked. Doubtful it's the transmission, some other guy said it could be the giubo and center bearing, but the mechanic said they look fine (whatever that means and again, don't know how closely he looked and if he even looked and didn't lie. This isn't the first time he could have missed something).

Any suggestions are welcome, kinda at a loss rn

[codeterrorist]

No idea at all if this is related or not. But I had the car shudder when on a highway and I accelerate hard to merge or to pass. It didn't happen if I did the acceleration smoothly.

I replaced coils and spark plugs and it worked. No errors at all were showing, even when scanned with Protool.

[Tambohamilton]

Originally Posted by codeterrorist

No idea at all if this is related or not. But I had the car shudder when on a highway and I accelerate hard to merge or to pass. It didn't happen if I did the acceleration smoothly.

I replaced coils and spark plugs and it worked. No errors at all were showing, even when scanned with Protool.

OP's car is diesel...

[Tambohamilton]

Originally Posted by harisb

Brought my E91 LCI N47 Automatic to have the timing chains swapped out (additionally swapped all 4 glow plugs as one of them was throwing a code) and until that point all was good.

Received the car back and now when doing hard accelerations with a full pedal the car is shuddering. This doesn't happen when going from 0, it starts on 3rd gear around 1.8k - 2.4k RPM. If I let it rip after that it doesn't shudder anymore. The car pulls well, gears shifts well. Vibration is constant in that RPM range, doesn't seem to correlate with speed. If I don't slam the accelerator, the shudder isn't that prominent. No codes, nothing.

Mechanic that swapped the chains said he checked his work and found no issues, but I don't know how closely he looked. Doubtful it's the transmission, some other guy said it could be the giubo and center bearing, but the mechanic said they look fine (whatever that means and again, don't know how closely he looked and if he even looked and didn't lie. This isn't the first time he could have missed something).

Any suggestions are welcome, kinda at a loss rn

Are the injectors coded correctly? He may have accidentally swapped them around when doing the work.