tighten nut on back of temp gauge - or sender? DIDN'T WORK!

Fri May 02, 2008 5:07 pm

My temp gauge is flicking about, then being steady, then flicking about and I'm paranoid about wreking my just rebuilt engine.

Can I tigten the nut on the back without removing whole clock assembly?

Is there anything else it could be (gauge worked fine before rebuild) but sender must have been removed / refited (new head).

Ta

Fri May 02, 2008 6:25 pm

It's just about possible to tighten the nut looking up underneath the dash, although removing the cluster is a simple enough job.
By far the most likely suspect!

Mon May 05, 2008 5:50 pm

Tightened nut, gauge still flicking about. Stays constant for a while, then flicks about then back to normal.

What should I try next?

Mon May 05, 2008 6:24 pm

I tried the nut, the temp sender, the temp gauge, the thermostat - all to no avail,

before changing the circuit board on the back. NOT the SI board but the other one. This finally cured my erratic temp gauge

.

Cost me about Ã‚£80 from the dealer. Might be able to source one from s/h dash unit.

Mon May 05, 2008 8:55 pm

My temp guage used to flick about in a crazy fashion. On mine it turned out to be a round connector under the throttle body, attached to the engine I think, which the temp sensor runs through. I just opened it up, cleaned up the rust and refitted. No more problems for over a year now.

Mon May 05, 2008 9:35 pm

hennabm wrote:I tried the nut, the temp sender, the temp gauge, the thermostat - all to no avail, before changing the circuit board on the back. NOT the SI board but the other one. This finally cured my erratic temp gauge .

Cost me about Ã‚£80 from the dealer. Might be able to source one from s/h dash unit.

Must have been a dry joint on a pin on the blue socket.
Five minutes with a soldering iron would have had the same result!

Mon May 05, 2008 9:39 pm

klu99apm wrote:My temp guage used to flick about in a crazy fashion. On mine it turned out to be a round connector under the throttle body, attached to the engine I think, which the temp sensor runs through. I just opened it up, cleaned up the rust and refitted. No more problems for over a year now.

This connector (found on six pots only) can be responsible for many for assorted misfires and poor running problems, as well as affecting the temperature gauge.
The main trouble spot is under the rubber boot of the lower half of the connector, rather than the plug and socket themselves. Water collects in this boot, if it penetrates the plug and socket, and rots through the wires.

Mon May 05, 2008 10:37 pm

I had the same problem Chris, with it reaching normal operating temperature then it would start fannying about going up and down.

At the weekend I changed my starter motor(unrelated totally) and moved the wiring harness, that is close to it, about a bit. Ever since then its sat rock solid. It may be just pure luck, it may not be. But might be worth a wiggle

Tue May 06, 2008 11:37 am

brian will i be able to swap out a circuit board from another cluster onto my m3 cluster....ie are they all the same? as mine does this aswell.... OR where may i fidn this bad contact (blue connector or gap in one of the tracks on the board?)

cheers
Karan

Tue May 06, 2008 12:32 pm

Brianmoooore wrote:
klu99apm wrote:My temp guage used to flick about in a crazy fashion. On mine it turned out to be a round connector under the throttle body, attached to the engine I think, which the temp sensor runs through. I just opened it up, cleaned up the rust and refitted. No more problems for over a year now.
This connector (found on six pots only) can be responsible for many for assorted misfires and poor running problems, as well as affecting the temperature gauge.
The main trouble spot is under the rubber boot of the lower half of the connector, rather than the plug and socket themselves. Water collects in this boot, if it penetrates the plug and socket, and rots through the wires.

Ahh, could this be linked to my occasional missfire? HOw easy is it to get to? do I need to take TB off?

Tue May 06, 2008 12:34 pm

Remove airbox and inlet boot & it's pretty easy to get to.

Tue May 06, 2008 12:34 pm

ChrisBarns wrote:
Brianmoooore wrote:
klu99apm wrote:My temp guage used to flick about in a crazy fashion. On mine it turned out to be a round connector under the throttle body, attached to the engine I think, which the temp sensor runs through. I just opened it up, cleaned up the rust and refitted. No more problems for over a year now.
This connector (found on six pots only) can be responsible for many for assorted misfires and poor running problems, as well as affecting the temperature gauge.
The main trouble spot is under the rubber boot of the lower half of the connector, rather than the plug and socket themselves. Water collects in this boot, if it penetrates the plug and socket, and rots through the wires.
Ahh, could this be linked to my occasional missfire? HOw easy is it to get to? do I need to take TB off?

yep TB and intake pipes off and you should be able to get to it....may need to remove inlet manifold to get to it properly