Sounds like part of that wheel speed sensor, for the ABS and possibly traction control etc. And rather odd for the toothed wheel part to fail. Are you certain it's not the sensor? They can and do fail.
It happens that Chris M. White formulated :
It might also be worth trying the same with presurised air to blow it out, and/or a vacuum cleaner, and/or a the largest paint brush you can poke through the sensors hole, then spining hub to try to remove the rust.
Just to confirm - The sensor and wiring are almost certainly fine, if they pass the 'ignition on', ABS light goes out test.
Adrian Caspersz was thinking very hard :
Not from Microsoft I hope?
Dave Plowman (News) wrote on 30/07/2021 :
Not this time, it passes the ignition on static tests.
Guitar pickups have a magnet in the coil. No need for rotating magnets - just teeth on a sensor ring going past will do the job
whether or not there are magnets in the ring (which I doubt: sensible to put one fixed magnet in the sensor itself and have the magnetic field modulated by a toothed steel ring) a common fault is rust and other magnetic materials building up in the ring teeth and making it less sensitive. A blast with a compressed airline and or applying rust removal liquids to the ring should sort it. If it has been failing at progressively lower speeds this is totally consistent with a weaker signal, cause by slow buildup of magnetic material in the teeth.
The Natural Philosopher explained on 30/07/2021 :
Thanks, I didn't know they were teeth, knowledge corrected.
Insurers are not allowed to decline to pay out for third party losses because of the condition of the vehicle causing the losses.
I assume you can't just replace the stub axle?
Cheers
Dave R
That is presumably so if you're hit by an unroadworthy vehicle the insurance company can't say 'sorry, unroadworthy, we're not paying'. But it doesn't mean they can't (try to) recover those costs from the person holding the insurance policy for that vehicle, because they are in breach of the insurance T&C and in doing so have caused the insurer a substantial loss.
Theo
whether the little light the dash tells you it's working properly
coupled with the potential for professional misconduct charges brought against manufactures (and individual employees thereof) who knowing or even negligently, engineer a systems that doesn't work, charges which can reach the level of imprisonment for manslaughter.
The sort of person who routinely drives around in an un-roadworthy car is unlikely to have sufficient funds to be worth suing
In the vehicle under discussion, they ARE magnets. However, there are
*other* vehicles which use a slightly different technique with a different kind of sensor and plain steel toothed rings to achieve the same end. You're more likely to find the toothed ring system used in distributors, IIRC.
The OP stated the car is a W211 of approx 2003 manufacture. Consequently, it will not have a toothed ring, but one made with a bunch of magnets imbedded around it. It's a known issue on this model that rust particles build up within the axle and are attracted to the magnets in the ring. Frequently the ring itself also rusts and can disintegrate entirely eventually. The rings are cheap enough, but getting at them is a bit of a PITA. Someone has suggested methods of removing the rust particles via the sensor hole - but good luck getting the sensor out as achieving that seemingly simple objective can be as big a PITA as getting to the ring!
I don't know that they are, I am just saying that's all they need to be.
As an engineer, that seems to me to be the simplest solution - lots of magnets on wheels seems to me to be a manufacturing nightmare
Are you sure? That seems to be to be an expensive and unreliable way to do it.
However, there are
Yes and yes. According to the OP it's a ~2003 W211 so it will use the magnet rings. And yes, it IS an expensive and unreliable technique!
No, they are not in breach of the T&C. See above.
The toothed-ring systems utilise variable reluctance sensors; the year and model of the car in question do not. Plus, the car in your video is a completely different year and model from the one under discussion.
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