Mechanical help required

M

MBZ4

Member
Hi guys, I'm looking for a little advise from the experts regarding a problem / diagnosis in my Z4 3.0Si E85.

Background to the problem

I was driving with everything running smoothly and then my traction control starting intermittently kicking in at pretty low revs and slowing the car (3/4th gear @ 2,500rpm). It carried on like this for a couple of miles and then seemed ok for the last couple of miles of the journey. I then took the car out the next day and the same thing happened, and this time the ABS, wheel pressure and brake lights all came on.

I decided it would be best to get BMW to have a look at it (Grassicks Perth) this morning. Booked it in for 11.30. Dropped off at 11.15. I had heard nothing by 14.30, so went back to the garage. They had not looked at the car by this point. I left before returning at 17.00 (30 mins before closing) as I had still heard nothing. The man at the desk asked me to wait in the customer lounge whilst he was pricing up the parts. Eventually came into the lounge at 17.30 to tell me what they had found.

Apparent problem

According to BMW the driveshafts are corroded and the ABS sensors are hitting them. I was informed the fix would involve both driveshafts and ABS sensors being replaced. The man also failed to price the parts and told me he would call tomorrow with a breakdown of costs.

My knowledge of this is pretty limited and all based on some googling. A friend who I spoke to earlier questioned the likelihood of both driveshafts corroding to the point of sensor contact at exactly the same time (as the car had no issues at all before the problem occurred). Looking online it seems the issue would either be a faulty sensor or the reluctor ring becoming out of shape leading to it contacting the sensor?

If anybody has experience or knowledge on this problem I would be most grateful to hear your advice as BMW implied the job would be well into 4 figures to carry out.

Thanks in advance,

Mike
 

Attachments

  • FullSizeRender.jpg
    FullSizeRender.jpg
    139.7 KB · Views: 1,381
From the sounds of it (and I'm not familiar with this problem, being new to the Z4 scene) the corrosion causing this contact probably needs dressing back with a wire wheel or a wire brush. There's probably about a 1-2 mm build-up that needs knocking off. If that's the case, the reaction and quote you've had should be criminal!

Can your friend whip your wheels off and get in there for a look? If you can confirm that a bit of corrosion is all that's causing your problem it might be worth finding a good local independent garage (ideally a BMW specialist but not crucial) to see if they'll clean it up for you. It might even be something you can do at home. Main dealers are often far too keen to replace components instead of diagnosing correctly/solving problems economically.
 
The battery voltage code would lead me to checking the battery before doing anything else. Many gremlins can come out with a battery in poor health but the car can still start up with no issues.
 
On previous cars I’ve owned the reluctor rings can corrode under the contact patch with the driveshaft, cracking the rings and causing the fault.
Separate rings were available online instead of new driveshafts from the manufacturer as a cheap fix, I’d go to an independent garage to avoid being fleeced.
Rob
 
Thanks for the responses guys - really appreciate it.

With regards to the battery - I think that was purely due to the car sitting for 3 weeks whilst I was on holiday (the problem occurred right before I left for holiday). The trip to the garage was the first time it had been started since I got home and that was only a 15 min drive.

Will take everyones advice and find a independent garage for a 2nd opinion.

If anyone has a recommendation for a good garage either in Fife or Stirling/Perth area let me know!

Thanks again,

Mike
 
Reluctor rings still seem available, some at under £10.

Example: https://m.bestpartstore.co.uk/2040326-mapco-sensor-ring-abs

Keep us posted on how you get on :)
 
We have done loads of reluctor rings on BMW driveshafts

It’s a common issue

We always change just the rings first, as sometimes, even though the sensor is slightly scored it can still operate correctly..

BMW wouldn’t even know how to fit a reluctor ring , they just fit shafts ...


A good Indy will sort you out swiftly and and under half of what BMW will want to charge, even in the worse case scenario
 
Thanks guys.

Had a call from BMW on my way home from work. They have priced the parts and labour. With some 'reductions' included the quote is just shy of £1,700 for the job!

Needless to say I won't be booking it in for the work to be done at BMW!
 
my wifes X3 had similar due to a reluctor ring growing due to corrosion. my local indy changed it for about £30-40 i think. he said he gets a lot of these on BMW especially after winter.
 
I had a 14 plate 535d xdrive in last week. BMW had quoted £2325 for new rear driveshafts as the rings were shot and all 4 boots were split. I charged him a tenth of that..

Mike
 
As others have said it will be the rings for the ABS. The hardest part of the job is removing the hub nut on my 120d Simon Thorpe motor services did mine in around 3 hours both sides off. Fitted one ring cleaned up the other but one sensor was damaged cost was under £200 all done on a Saturday morning. I did help them a little by cleaning the hub nut with a wire wheel and soaking it in release oil for a week sometimes they have to air chisel them off mine came off ok Simon charges £60 per hour and based in Grimsby
 
Yeh, assuming the wheel speed sensors aren't destroyed I don't think you should be paying much more than £200 to get this sorted. I changed them on my old Z3 and although it does take a while, it's not at all complicated. £1,700 from BMW is just laughable (as usual).
 
You must log in or register to reply here.
Back
Top Bottom