Downshift issue????

[rstoughy]

So here's one I've not heard of yet.

Was out with the car, Got a dash full of lights and suspected it was just a wheel speed sensor (which it was as confirmed by the diagnostics machine). No problem, ordered one and carried on.

Now FF>>> a day or so and I'm pulling into a slip road so changing down the box....6th-5th..(auto blip)..5th-4th (auto blip)..4th-3rd....no gear engaged and the revs bouncing off the limiter. Tried a full press (a stamp) of the throttle pedal but nothing.
Switched car off and re started and all fine again.

Anyone seen this before and anyone have any idea what the issue could be?
Thoughts are,


SMG Pump issue? (its original and 78k miles old)
Throttle Position sensor issue?
ECU / brain confusion with downshifts and wheel speed sensor all getting mixed up with one another?
Something else?


Thanks :thumbs:

[s.mac]

Mate, I had exactly the same last week. 1st time cars been out this year, MOT and service required.
Dash lit up like Blackpool illuminations on the way to BMW. Pulling in to the car park it rev?d by itself for a second. I kept it running to show my sons mate, he took it in and did a full check over and it was a wheel speed sensor.

[rstoughy]

Had to switch mine off. It was not dropping and bouncing off the limiter :hahaha: :hahaha: :hahaha:
Felt like I should be sitting in a supermarket car park at 23:00 with the Max Power brigade :bigcry:

[J77]

Happened to me. Your wheel speed sensor should fix it!

http://www.cslregister.com/forum/showpost.php?p=203408&postcount=5

[Mike R]

Has it logged anything in the DME?

[rstoughy]

Has it logged anything in the DME?

No Mike just N/S front sensor.

Cheers guys I'll pull the finger out and get the new one on and hopefully that's the end of it.
Gutted really as was going to take it for a run down to Donington this weekend past but ran out of time to replace it so the old faithful S8 had to step in.

[robmug]

Does there come a point at which preventative replacement of wheel speed sensors is viable?
What?s the cost (parts/labour) involved?
As far as I know mine not hasn?t had any such issues?92k miles

[rstoughy]

Does there come a point at which preventative replacement of wheel speed sensors is viable?
What?s the cost (parts/labour) involved?
As far as I know mine not hasn?t had any such issues?92k miles

I've just bought 4x Bosch ones for the race car and think it was about ?30 per sensor. I'm pretty sure the OEM ones are also Bosch but can't guarantee that.

Labour wise I couldn't tell you as I do all that sort of stuff myself.

I've done 25k miles with this car and this is the 2nd wheel speed sensor to fail. Last one was a rear.

[CraigMillwardCroft]

Mate, I had exactly the same last week. 1st time cars been out this year, MOT and service required.
Dash lit up like Blackpool illuminations on the way to BMW. Pulling in to the car park it rev?d by itself for a second. I kept it running to show my sons mate, he took it in and did a full check over and it was a wheel speed sensor.

Mine did that on way to service with Gareth in July 2019, he fixed wheel speed sensor, car then did 800 miles to Le Mans first trackday out car was fine second day car went back to reving its nuts of randomly, some other BMW race car people did a diagnnostic to tell me the other side had gone faulty now, car not run since August 2019 stuck at my house in France

[CraigMillwardCroft]

I've just bought 4x Bosch ones for the race car and think it was about ?30 per sensor. I'm pretty sure the OEM ones are also Bosch but can't guarantee that.

Labour wise I couldn't tell you as I do all that sort of stuff myself.

I've done 25k miles with this car and this is the 2nd wheel speed sensor to fail. Last one was a rear.

Mine has done 27k and that's now two sensors gone

[Mike R]

I guess when one goes, like coil-packs, that's an indication to replace them all.....

However, I do know that from experience they can just randomly "lose" the connection to the speed sensor. I have only had this happen once though and typically it was on my way to the 'ring (and the first time I was taking the CSL), so I was reluctant to run it with out traction control operational for my first outing there in a new to me car.

I was really lucky (like Craig) that there was a guy there from Scotland with his own E46 M3 who was a whiz with INPA and had his lap-top with him. He plugged it in and immediately diagnosed that it was one of the wheel-speed sensors, where the DME had somehow become confused and decided it didn't want to communicate with one of them. He reassigned it and it's never been a problem since (and that was 8 years ago)....

Total cost - I had to give him a passenger lap :beer: .

[rstoughy]

I guess when one goes, like coil-packs, that's an indication to replace them all.....

However, I do know that from experience they can just randomly "lose" the connection to the speed sensor. I have only had this happen once though and typically it was on my way to the 'ring (and the first time I was taking the CSL), so I was reluctant to run it with out traction control operational for my first outing there in a new to me car.

I was really lucky (like Craig) that there was a guy there from Scotland with his own E46 M3 who was a whiz with INPA and had his lap-top with him. He plugged it in and immediately diagnosed that it was one of the wheel-speed sensors, where the DME had somehow become confused and decided it didn't want to communicate with one of them. He reassigned it and it's never been a problem since (and that was 8 years ago)....

Total cost - I had to give him a passenger lap :beer: .

Was I not there and was that not my pal Laurence? I seem to remember he did something to your car outside the PK while we all sat and drank many many beers :hahaha: :hahaha:

[CraigMillwardCroft]

I guess when one goes, like coil-packs, that's an indication to replace them all.....

However, I do know that from experience they can just randomly "lose" the connection to the speed sensor. I have only had this happen once though and typically it was on my way to the 'ring (and the first time I was taking the CSL), so I was reluctant to run it with out traction control operational for my first outing there in a new to me car.

I was really lucky (like Craig) that there was a guy there from Scotland with his own E46 M3 who was a whiz with INPA and had his lap-top with him. He plugged it in and immediately diagnosed that it was one of the wheel-speed sensors, where the DME had somehow become confused and decided it didn't want to communicate with one of them. He reassigned it and it's never been a problem since (and that was 8 years ago)....

Total cost - I had to give him a passenger lap :beer: .

Mine would reset then soon as car moved went off again, so trailered back to my house in France, by the very helpful Delta racing on there way back to Gurnsey

[CraigMillwardCroft]

Was I not there and was that not my pal Laurence? I seem to remember he did something to your car outside the PK while we all sat and drank many many beers :hahaha: :hahaha:

:thumbs:

[Mike R]

Was I not there and was that not my pal Laurence? I seem to remember he did something to your car outside the PK while we all sat and drank many many beers :hahaha: :hahaha:

It was indeed :thumbs: .