Vibration under light acceleration before downshifts
08-31-2018, 11:18 PM
#1
Banned
Thread Starter
Vibration under light acceleration before downshifts
Hi @ll,
I have been trying for some time now, to pinpoint a vibration issue on my wifes ML without success.
It's a 2008 ML320 CDI with almost 200K.
Engine sounds normal and it shifts fine.
Symptom:
Cruising down the highway and accelerate gently.
Car starts vibrating around 1600 rpm and usually stops vibrating around 2000 rpm and downshifts.
It always seems to vibrate ( higher gears) just before it downshifts.
(Feels like you are driving over those rumble strips and seems to be coming from the back of the car)
If I keep accelerating gently, vibration stays the same until it disappears around 2000 rpm.
If I let of the gas, vibration disappears instantly.
If I step on the gas, it vibrates hard until it disappears around 2000 rpm.
Today I finally crawled under the car and had a look at engine mounts (seem fine from what I was able to see of them). Revved the engine to see if engine is rocking. Seems OK
Looked at Transmission mount and rear flex disc. No cracks or visible damage.
Checked front and rear axles. Passenger side, front and back, seem to have a tiny bit more play than driver side.
Transmission Flush, Fuel Filter and Terra-Clean De-carbonisation were done when we bought the ML back in April 2016 at MB Dealer.
Maybe one of you guys has an idea on what I could check as well before I have to bring it to the Dealer for a check-up.
Regards
Heiko
EH! Canada
I have been trying for some time now, to pinpoint a vibration issue on my wifes ML without success.
It's a 2008 ML320 CDI with almost 200K.
Engine sounds normal and it shifts fine.
Symptom:
Cruising down the highway and accelerate gently.
Car starts vibrating around 1600 rpm and usually stops vibrating around 2000 rpm and downshifts.
It always seems to vibrate ( higher gears) just before it downshifts.
(Feels like you are driving over those rumble strips and seems to be coming from the back of the car)
If I keep accelerating gently, vibration stays the same until it disappears around 2000 rpm.
If I let of the gas, vibration disappears instantly.
If I step on the gas, it vibrates hard until it disappears around 2000 rpm.
Today I finally crawled under the car and had a look at engine mounts (seem fine from what I was able to see of them). Revved the engine to see if engine is rocking. Seems OK
Looked at Transmission mount and rear flex disc. No cracks or visible damage.
Checked front and rear axles. Passenger side, front and back, seem to have a tiny bit more play than driver side.
Transmission Flush, Fuel Filter and Terra-Clean De-carbonisation were done when we bought the ML back in April 2016 at MB Dealer.
Maybe one of you guys has an idea on what I could check as well before I have to bring it to the Dealer for a check-up.
Regards
Heiko
EH! Canada
09-13-2018, 10:06 PM
#3
Banned
Thread Starter
Hi again,
Went through the easy and obvious possibilities and didn't find anything wrong. Had the dealer look at it and run star software. They also pulled the transmission pan and found lots of metal particles. They stopped there and suggested to replace the transmission for 7950 + tax and labor. Are you kidding me???
I decided to rebuild the transmission myself!
Has anybody done that and could suggest a rebuild kit?
Also be helpful to get my hands on some documentation with proper steps and most importantly torque values for all the bolts.
(I replaced the engine oil cooler last December by myself and think this job can't be much harder.)
Thanks for any pointers in advance.
Went through the easy and obvious possibilities and didn't find anything wrong. Had the dealer look at it and run star software. They also pulled the transmission pan and found lots of metal particles. They stopped there and suggested to replace the transmission for 7950 + tax and labor. Are you kidding me???
I decided to rebuild the transmission myself!
Has anybody done that and could suggest a rebuild kit?
Also be helpful to get my hands on some documentation with proper steps and most importantly torque values for all the bolts.
(I replaced the engine oil cooler last December by myself and think this job can't be much harder.)
Thanks for any pointers in advance.
