Erratic Temperature Reading

bazzam111 · Post by **bazzam111** » Mon May 21, 2007 10:43 pm

Went for a long blast down to 'englandshire' and on the M6 the temperature reading started 2 go nuts!!!

Temperature reading changed about 20 deg in 2 secs! Checked levels, coolant colour, no signs of 'mayo' and the car ran fine. Settled out at reading 5 deg below wot it normally does.
Me thinks a duff temp. sender to the 'Stack.'i.e. the blue one. Any thoughts before I go and get a new one????
Cheers Bazza

robin · Post by **robin** » Mon May 21, 2007 10:51 pm

Could also be broken wire at the sensor or earthing problem. However, it is often the sensor it seems, so may as well change it for what it costs ...

Cheers,
Robin

roadboy · Post by **roadboy** » Mon May 21, 2007 11:34 pm

If its jumping around a lot I'd put money on it being an earthing problem. If it is, one day you'll jump in the car and it just won't start. Nice!

HTH

Dan@JPS

bazzam111 · Post by **bazzam111** » Tue May 22, 2007 12:30 pm

Thanks for the replies!

The trip/fuel readout on the Stack does flicker when I apply the brake as well so I'll start with a suspect earth.
Temp. sensor looks a 'bar-steward' to get at anyway. As for the earth fault I'll redo the battery negative to chassis connection at the front.
Any other (clean) suggestions where to look for an earthing fault???

cheers!
Bazza

Rich H · Post by **Rich H** » Tue May 22, 2007 3:21 pm

Change the temp senders. Mine have gone 3 times now. Change both just in case.

Yes they are a royal PITA to get to!

robin · Post by **robin** » Tue May 22, 2007 4:59 pm

bazzam111 wrote:Thanks for the replies!
The trip/fuel readout on the Stack does flicker when I apply the brake as well so I'll start with a suspect earth.
Temp. sensor looks a 'bar-steward' to get at anyway. As for the earth fault I'll redo the battery negative to chassis connection at the front.
Any other (clean) suggestions where to look for an earthing fault???
cheers!
Bazza

Check the earth strap from the chassis to the gearbox.

Cheers,
Robin

tut · Post by **tut** » Tue May 22, 2007 6:22 pm

In the end, on N1 TUT, we got so pissed off that we ran a lead from the battery negative, through the central tunnel, to the engine, and that cured it.

Mine was however a starting problem as well, but I still have to take the keys out and suffer a slow disharge regardless.

And would you believe N3 has just started doing the same over the last few days? Would only chug over this morning, so looks like the same again.

The rear earthing point is easy to get at to clean, but the main one from the battery to the N/S chassis bolt is a bugger to access.

tut