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

[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
Felt like I should be sitting in a supermarket car park at 23:00 with the Max Power brigade

[J77]

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

http://www.cslregister.com/forum/sho...08&postcount=5

[Mike R]

Has it logged anything in the DME?

[rstoughy]

Originally Posted by Mike R

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]

Originally Posted by 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

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]

Originally Posted by 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.

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]

Originally Posted by rstoughy

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