THERMOSTAT or TEMP GUAGE

[spacemarshall]

i bought a 1985 325e 2 weeks ago and the dashboard temp guage has always been squirrely - just before i did a coolant flush and thermostat check it started to not register anything sometimes on short trips and occasionally on longer trips.

now after successful coolant flush change without replacing thermostat it wont register any temp at all.

it flickers when i start engine and all dash instruments come on but it stays way below cold blue end of temp range never moving.

any ways to check if bad guage, bad sensor (in radiator top, right???). bad wires between them or thermostat

[Jeron]

The temp gauge sensor should be on the engine (head likely) not the radiator. Bad wiring is a very good possibility, test the sensor to see what it is registering.

[spacemarshall]

i put in new thermostat and am getting steady and predictable readings. as far as i can tell the sensors are going into thermostat housing!!!???

it works - im happy!!!

[Jeron]

Glad you got it fixed. I thought it never got warm based on these:
"it wont register any temp at all."
"but it stays way below cold blue end of temp range never moving"


I skimmed over this "not register anything sometimes on short trips and occasionally on longer trips" which is an indication of bad thermostat.