Oonnzo
Active Member
- Joined
- Jul 5, 2020
- Messages
- 31
- Reaction score
- 28
- Your Mercedes
- 2010 W251 OM642
Hi all - over the past couple of months I’ve taken this time to do an overhaul of my 2010 R300 CDI with the OM642.
It has hit 140k kms and i’ve had it for 90k kms of those. Recently I’ve noticed turbo surge/chatter when letting off the accelerator as well as a droning /reverberation resonating in the intake at high constant speeds.
I was also getting lots of blowby (as you can see in the video) which has now been fixed with a replacement PCV.
Some background - I changed over my COMAND unit to a Kenwood double din and was waiting for the MOST amplifier converter so there was no music in the car. Maybe that is why I was hearing all these sounds!
Re the overhaul, I’ve done, Lower ball joints, front airbag, front rotors/brake pads, transmission fluid, transfer case and both diffs and std engine oil and filter change (and now the 2 year old reconditioned strut has failed!)
Videos of the Turbo chatter / surge with intake on and off.
Intake On
Intake off
I originally thought the sound was drivetrain related (given the recent drivetrain work) but that was quickly dismissed as it happened in park/neutral. I then narrowed it down to turbo chatter/surge. I pulled the intake pipe from the front of the car and put my ear to it and it is definitely turbo chatter.
Does anyone notice the chatter in their cars? It is prominent when lifting off at 1500 rpms plus revs (I guess when the turbo starts spooling). It is reverberating in the airbox and creating a grinding like sound.
In the second clip you can see there is no grinding/whooshing sound with the air intake off but boost is clearly being pushed back out the intake.
I’ve checked the actuator and it looks good (removed it and checked the contacts and also observed the actuation). The boost is also solid and doesn’t fluctuate (using obd scan tool to observe).
I ordered an icarsoft mb2 and it showed a exhaust backpressure code once but it hasn’t come up since. I’ve ordered a new one anyway and I also ordered the radial shaft seal ring for the crankcase breather mentioned in the blue smoke thread on here.
Has anyone seen something like this before or have any ideas in what it could be? Any pointers are appreciated!
It has hit 140k kms and i’ve had it for 90k kms of those. Recently I’ve noticed turbo surge/chatter when letting off the accelerator as well as a droning /reverberation resonating in the intake at high constant speeds.
I was also getting lots of blowby (as you can see in the video) which has now been fixed with a replacement PCV.
Some background - I changed over my COMAND unit to a Kenwood double din and was waiting for the MOST amplifier converter so there was no music in the car. Maybe that is why I was hearing all these sounds!
Re the overhaul, I’ve done, Lower ball joints, front airbag, front rotors/brake pads, transmission fluid, transfer case and both diffs and std engine oil and filter change (and now the 2 year old reconditioned strut has failed!)
Videos of the Turbo chatter / surge with intake on and off.
Intake On
Intake off
I originally thought the sound was drivetrain related (given the recent drivetrain work) but that was quickly dismissed as it happened in park/neutral. I then narrowed it down to turbo chatter/surge. I pulled the intake pipe from the front of the car and put my ear to it and it is definitely turbo chatter.
Does anyone notice the chatter in their cars? It is prominent when lifting off at 1500 rpms plus revs (I guess when the turbo starts spooling). It is reverberating in the airbox and creating a grinding like sound.
In the second clip you can see there is no grinding/whooshing sound with the air intake off but boost is clearly being pushed back out the intake.
I’ve checked the actuator and it looks good (removed it and checked the contacts and also observed the actuation). The boost is also solid and doesn’t fluctuate (using obd scan tool to observe).
I ordered an icarsoft mb2 and it showed a exhaust backpressure code once but it hasn’t come up since. I’ve ordered a new one anyway and I also ordered the radial shaft seal ring for the crankcase breather mentioned in the blue smoke thread on here.
Has anyone seen something like this before or have any ideas in what it could be? Any pointers are appreciated!
