Overheating?

[samiebarela]

I have a 91 318i convertible that shows a temp gauge reading between 12 & 2 o'clock. My temp gauge is not steady but is constantly fluctuating erratically.
I have replaced the radiator, thermostat, and radiator hoses. The water pump and fan clutch appear to be operating fine.
My mechanic says to replace the coolant temp sensor, do this sound like the right thing to do??

Any help would be much appreciated.

[jlevie]

That would be an appropriate course of action as would an independent check of engine temperature.

[Liam]

One thing to check on an erratic gauge is the nut that holds the gauge to the conductor plate (goes through to the back of the cluster), they get loose and cause erratic (and usually high) readings.

[samiebarela]

Thanks guys, I will try both of those suggestions.

[Adrian_Visser]

I have the same problem it is starting to get to me the damn gauge will read high on me then flick back down to normal, at least my old car read low so I thought is was colder than it was lol.

[The_Nietzschean]

One thing to check on an erratic gauge is the nut that holds the gauge to the conductor plate (goes through to the back of the cluster), they get loose and cause erratic (and usually high) readings.

How exactly do you access this? I have the same problem and think it is electrical.

[jlevie]

To properly fix the the temp gage you have to remove the cluster, disassemble it, and re-flow solder on the pads where the temp and fuel gage mount to the PCB. It is a bit tedious, but not difficult.