Hey gang,

I replaced my engine coolant temp sensor (the fellow on the intake manifold, MEK100160) because it was off by about 12 degrees centigrade. On my way to work, my temp gauge starts climbing so I pull over. Engine doesn't feel hot at all and lower rad hose is cold. I check with my IR gun and I see a healthy 83 degrees. I drive home with the gauge climbing up to the red, and I check again with the IR gun, 83 degrees. Hawkeye shows a staggering 130.

Is my new sensor bad? or have I done something wrong?

Thanks in advance

 

When you replaced the sensor, did you bleed the coolant system? Did you clean the connectors on the wiring harness?

It's certainly possible that the sensor is bad, but let's run through everything else before buying parts.

 

I bled the system but likely not well enough at all, and I did not clean the wiring harness at all, just swappy swappy. I think its just a restrictive sensor right? so it could just be a bad connection?

Thanks

 

It's a resistive sensor, so you want as clean of a connection as you can get between the connectors or the resistance of the grime and such becomes part of the resistance of the sensor and throws things off.

I've never actually replaced this particular coolant sensor, but I also know the torque spec from the RAVE manual is about 15 lb-ft, and if you torqued the hell out of it, it's quite possible to crack the porcelain insulator on a coolant sensor, which can result in incorrect readings.

 

I hope I didn't torque the hell out of it, but I might have. Getting a wrench on the damn thing was a pretty horrible task. Ill try cleaning the thing off tonight and see what happens.

Thanks

 

I’ve had cheap aftermarket ones report much higher temps vs OEM units.