RPM Drop & Lurch when decelerating at slow speed
04-28-2017, 10:46 PM
#1
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2011 GLK350 4MATIC
RPM Drop & Lurch when decelerating at slow speed
Hey all
Loving my new GLK, got it about 7 months ago with ~55k miles from Carmax. Put about 10k miles on it since. Was used as a fleet car before this.
Anyway, I've been having this issue where, when I'm going slow (under 30 mph) such as through a neighborhood or approaching a light/stop, my car will lurch when coming down to 1500 rpm.
It's repeatable at this exact rpm and at slow speeds. The rpms will drop from 1500 to about 1000 and the car will lurch without any input from me. I've had shifting issues with past cars and it's been indicative of bad transmissions so I'm getting concerned. This thing is almost brand new to me...
I have read elsewhere that sometimes resetting the TCU could help. I just got service B done and replacement of my ATF. I haven't noticed much of a difference.
Anyone have expertise in this area or have this before? I find it interesting that I can pinpoint the exact moment that it will lurch. I can put it in neutral when it approaches 1500 and it will not lurch at all. I haven't tried setting the gear and seeing if it's a downshifting issue, but wouldn't downshifting bump the revs up and not down?
This occurs in Sport and in Economy mode, so I'm not sure how to isolate this issue further.
Any input would help. Thanks
Loving my new GLK, got it about 7 months ago with ~55k miles from Carmax. Put about 10k miles on it since. Was used as a fleet car before this.
Anyway, I've been having this issue where, when I'm going slow (under 30 mph) such as through a neighborhood or approaching a light/stop, my car will lurch when coming down to 1500 rpm.
It's repeatable at this exact rpm and at slow speeds. The rpms will drop from 1500 to about 1000 and the car will lurch without any input from me. I've had shifting issues with past cars and it's been indicative of bad transmissions so I'm getting concerned. This thing is almost brand new to me...
I have read elsewhere that sometimes resetting the TCU could help. I just got service B done and replacement of my ATF. I haven't noticed much of a difference.
Anyone have expertise in this area or have this before? I find it interesting that I can pinpoint the exact moment that it will lurch. I can put it in neutral when it approaches 1500 and it will not lurch at all. I haven't tried setting the gear and seeing if it's a downshifting issue, but wouldn't downshifting bump the revs up and not down?
This occurs in Sport and in Economy mode, so I'm not sure how to isolate this issue further.
Any input would help. Thanks
05-01-2017, 05:13 PM
#2
Super Member
Try resetting th throttle/driving habit, the car adapts to driver habits and it's always a good thing idea to refresh the memory.
key to on position without starting the car, step on gas all the way and hold, turn off car but do not take out the key , wait a few seconds and then turn to on position. Hopefully your keeping your foot on the has the whole time, now you turn off the car and take the key out, release the gas pedal and let it sit for 30 minutes
key to on position without starting the car, step on gas all the way and hold, turn off car but do not take out the key , wait a few seconds and then turn to on position. Hopefully your keeping your foot on the has the whole time, now you turn off the car and take the key out, release the gas pedal and let it sit for 30 minutes
03-01-2021, 02:59 PM
#4
Member
Try resetting th throttle/driving habit, the car adapts to driver habits and it's always a good thing idea to refresh the memory.
key to on position without starting the car, step on gas all the way and hold, turn off car but do not take out the key , wait a few seconds and then turn to on position. Hopefully your keeping your foot on the has the whole time, now you turn off the car and take the key out, release the gas pedal and let it sit for 30 minutes
key to on position without starting the car, step on gas all the way and hold, turn off car but do not take out the key , wait a few seconds and then turn to on position. Hopefully your keeping your foot on the has the whole time, now you turn off the car and take the key out, release the gas pedal and let it sit for 30 minutes
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BalaJake (05-12-2021)
