Lumpy Transmission >1250RPM <1750RPM

Tiger_JCS · 01-29-2022, 02:33 AM

Hi, I just wanted to get some ideas from other users. First time post and although I’ve tried looking through the posts, this seems to be quite a specific problem.

I’ve had my X3 2.0D M Sport (automatic) for about 6 years from around 50k miles to 150k miles. Service is all up to date and it has had some major works on it including having to replace the majority of the transmission not long after getting it. But that’s another, tedious, expensive, and depressing story.

I digress. Recently I have noticed that at low RPM the X3 seems to jerk, almost like the gear is slipping. This is more pronounced when it’s low rpm and turning left. The vehicle broke down prior to Christmas (again, a real magic moment) and that was due to failure of the HP fuel pump which in turn nailed all the injectors. Got the car back yesterday with its new injectors, HP fuel pump and coil module (plus system flush). But it’s still lumpy at the low RPM.

Driving last night I narrowed it down to between 1250RPM and 1750RPM with the gear change anything but smooth and the car is unable to maintain constant revs in the range, instead dropping and returning constantly. Outside of that it’s fine, in fact it’s brilliant beyond 2000RPM. But of course I cannot cut around town at 2000RPM.

I have thought (and it has been suggested to me) that I need to change the transmission fluid as the rebuilt system has been in place for about 80k miles. I have also thought it could be a diff (I’ve had both of those go as well). But I would have expected to see more symptoms in higher RPM or greater fuel use, but that doesn’t seem to be present.

I’m loathed to take it to a main dealer but if I must (already £3k down from the most recent repairs), I would like to have some idea of what it could be.

Any thoughts?

Tiger_JCS · 02-04-2022, 08:32 AM

Just to follow up, I spoke to a BMW specialist who advised changing the front tyres (they were due changing) and said that when you change one set, as I had, you should change the other, which I hadn’t. And that advice was free!

So I did that, and 90% of the lumpiness is now gone. I will allow the tyres to bed in and see if the remaining lumpiness goes as the transmission re-calibrates to the new tyres. However, he suggested that if it doesn’t solve the issue, it’s likely the EGR valve that either needs a filter change or has stuck open.

Thought I would follow up just in case anyone else has a similar issue.

01-29-2022, 02:33 AM	#1
Tiger_JCS Registered 0 Rep 3 Posts Drives: BMW X3 2.0D M Sport Join Date: Jan 2022 Location: Oxfordshire iTrader: (0)	Lumpy Transmission >1250RPM <1750RPM Hi, I just wanted to get some ideas from other users. First time post and although I’ve tried looking through the posts, this seems to be quite a specific problem. I’ve had my X3 2.0D M Sport (automatic) for about 6 years from around 50k miles to 150k miles. Service is all up to date and it has had some major works on it including having to replace the majority of the transmission not long after getting it. But that’s another, tedious, expensive, and depressing story. I digress. Recently I have noticed that at low RPM the X3 seems to jerk, almost like the gear is slipping. This is more pronounced when it’s low rpm and turning left. The vehicle broke down prior to Christmas (again, a real magic moment) and that was due to failure of the HP fuel pump which in turn nailed all the injectors. Got the car back yesterday with its new injectors, HP fuel pump and coil module (plus system flush). But it’s still lumpy at the low RPM. Driving last night I narrowed it down to between 1250RPM and 1750RPM with the gear change anything but smooth and the car is unable to maintain constant revs in the range, instead dropping and returning constantly. Outside of that it’s fine, in fact it’s brilliant beyond 2000RPM. But of course I cannot cut around town at 2000RPM. I have thought (and it has been suggested to me) that I need to change the transmission fluid as the rebuilt system has been in place for about 80k miles. I have also thought it could be a diff (I’ve had both of those go as well). But I would have expected to see more symptoms in higher RPM or greater fuel use, but that doesn’t seem to be present. I’m loathed to take it to a main dealer but if I must (already £3k down from the most recent repairs), I would like to have some idea of what it could be. Any thoughts? Last edited by Tiger_JCS; 01-29-2022 at 02:53 AM.. Reason: Spelling
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02-04-2022, 08:32 AM	#2
Tiger_JCS Registered 0 Rep 3 Posts Drives: BMW X3 2.0D M Sport Join Date: Jan 2022 Location: Oxfordshire iTrader: (0)	Just to follow up, I spoke to a BMW specialist who advised changing the front tyres (they were due changing) and said that when you change one set, as I had, you should change the other, which I hadn’t. And that advice was free! So I did that, and 90% of the lumpiness is now gone. I will allow the tyres to bed in and see if the remaining lumpiness goes as the transmission re-calibrates to the new tyres. However, he suggested that if it doesn’t solve the issue, it’s likely the EGR valve that either needs a filter change or has stuck open. Thought I would follow up just in case anyone else has a similar issue.
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