Erratic Temp Gauge

Took the E30 M3 out today and the Temp gauge was flicking all over the place (bit alarming at first)

Is this likely to be the Brown temp sensor or are there other causes ?

(apart from it actually running hot as this wasn't the case , I did stop and check to make sure )

cheers

Andy

When its doing it. Smack the top of the dashboard above the clocks quite hard.

If it resets the needle to another point, its the earth points on the back of the clock unit.

I renewed all 3 senders and wiring loom on the coolant system before finding this out

Though sometimes the wiring to the sender in the thermstat can get damaged.

Edited by rr_ww

Yup

Maybe not the prettiest diagnostic check I've ever done! but cant argue with the results.

andyclient wrote: i have tried cleaning and re seating the sensor plug will try the dash bashing diagnostics when out and about tomorrow Will keep you posted Andy

I had this with mine, I changed all the instruments, as mine had grey/silver dials so replaced them all with brand new items, sonce then the temp was irratic, do a search and you'll see. All ok now though.

If this doesn't work, a rather large lump hammer usually works wonders  initially anyway!

Update on the temp gauge.

It does appear to respond to the dash slapping modification so

 its instrument cluster out and have a poke about with the earth

connections on the back as mentioned by Rich I guess.

Are these connections obvious on removal of the instrument pod ?

Did check the earth strap as mentioned by M3Booboo that all appears sound.

Thanks everyone for their input

Cheers

Andy

jon90 wrote: Theres a small nut on the back of temp guage,simply tighten. Jon

excellent thanks for that Jon

While i have the instrument pod out is it much of a job to change the dials or is this best left to a specialist ?

 Only the po put a set of white dials in  , 

 i got the originals with the car and wondered if this may be the opportunity i was looking for to put them back to original.

Cheers

Andy