E34 Speed Sensor

[jasrob]

This is my first post - my father-in-law who is a bit of an E34 nut (and ond of the main reasons I now own one) put me onto this site.

I have an '89 manual 535i and ever since owning it (over 3 years now), the cruise control has never worked properly - at about 100km/h (legally the fastest we can drive in most places in Australia), the engine surges and you can see the speedo needle wavering although you are travelling at a constant speed. This hasn't worried me too much, but for the last 6 months (or maybe more), I only intermittently have a speedo, so generally have to rely on the taco to figure out what speed I am doing.

I found a section on the www.bmwe34.net site saying this is most likely an issue with the speed sensor in the diff which may need replacing.

I think I have the correct part name and number - "Pulse Generator, Speedometer" 62 16 1 379 874. If someone can confirm this for me, that would be great.

Would welcome any comment on this issue as I don't want to go replacing the speed sensor if it is not the right thing to do (I understand it is a bit of a process to do as well). Some further information that may be useful is that I have also had problems with the instrument cluster electronics - fuel gauge only works intermittently, have issues with cluster lights (mostly in digital display, but have occasionally lost all cluster lights) and have also had a locked up taco and econo gauge a couple of times. I followed a process on the bmwe34.net site to replace several electrolytic capacitors, which didn't really change much.

Thanks for any info you can give! :D

[colo525i]

Had the same issue, intermittent speedo readout at a constant speed, and the cruise would surge. Swapped the sensor and all is well. It is a bit of a pain to get at, i found taking off the right rear wheel helped a ton.

[myles]

Thats the right part number.

[bmwrp8]

Hi jasrob and welcome:D i had the same problem that you have before, and i changed the speed sensor in the diff. although my mechanic told me we could try cleaning it first but since it was there already i decided to change it anyways. after that all is ok:)

[jasrob]

Thanks everyone. I did enquire about buying the part from a BMW dealer, but it looks like getting it from Germany is going to cost around AUD$300. Haven't checked second-hand cost as of yet. My mechanic reckons that it might be best trying to re-solder the instrument cluster panel where the connectors attach before I spend the money.

[MBXB]

Try bmaparts.com.

[pundit]

Thanks everyone. I did enquire about buying the part from a BMW dealer, but it looks like getting it from Germany is going to cost around AUD$300. Haven't checked second-hand cost as of yet. My mechanic reckons that it might be best trying to re-solder the instrument cluster panel where the connectors attach before I spend the money.
If you need a new speed sensor try these guys...

WELCH AUTO PARTS
151 Islington Street,
COLLINGWOOD 3066
BMW, Mercedes, VW, Volvo & Audi parts
Tel: 9415 8787 or Greg on 0418 578 740
Trade or special prices to members

They're local and I've found them pretty reasonable.
I got a brand new replacement speed sensor for my 535i for around $130.00 from memory.

[BigKriss]

Welcome a fellow Aussie. **** BMW $tealer$, I did the speed sensor about 6 months ago. It's located on the differential. I had the same symptoms as yourself, the speedo would read all over the place affecting the cruise control. I replaced mine from BMA for about usd$30.It fixed it.

Never buy from the dealer expect for coolant and oil filters.

One thing I noticed on the speed sensor that it had fine metal shavings attached to it. This maybe one reason why it wasn't working properly, I replaced mine so I don't know if cleaning it would have made a difference. It took me about 40mins to replace. It was hard to get to the two screws that held it in place, but I eventually did it.

You have to lift the rear of the car with a jack. easy job.