Hi Guys,

I have another big problem in mine B210, Driving of 10 min drive Heat Sensor goes to the H Side and wait there will not come to C side until i stop the car an keep for some time ,but when i check the engine coolant it is not so hot, is that a bad sensor or wiring problem ? how the heat sensor is connected to dash with 12 V and Ground etc ?

Thanks
Regards
Sumith

The temperature sensor is on the engine.
The temperature gauge is in the dashboard.

Get a thermometer and read the temperature of the upper radiator hose.

I suspect the temp sensor or 'sender' unit in the engine is faulty. I have replaced several in my time with cars, they don't last forever. The fault appears just as you have described - and once the sender is replaced, the gauge works perfectly again. You can test the sender by disconnecting the wire from it, then measuring the resistance from the sender terminal to engine earth. It should ONLY be zero Ohms (or close to) when the engine is boiling. Should normally be a value betw 100s to 1000s of Ohms when engine is cold (from memory - better you look up a service manual for true resistance vs temp values).

From my experience the senders usually die by going intermittently low resistance, which fools the dash gauge into displaying a HIGH temp, when the coolant water is in fact normal temp and nothing to worry about.

Good luck!

Sounds like good advice.

The resistance at normal should be 116 ohms.
For more informatio see Tech wiki: Temperature Gauge

Hi Guys,

Got My Temp Gauge done, i removed it and cleaned it and fixed it up , i think now it is running perfect now, it always sits near the middle of Gauge or just before the middle in normal driving condition,

Thanks
Regards
Sumith