Hi all, I'm having an issue where my cluster coolant gauge is spiking up to around 2 o'clock. That usually means it's running pretty warm if it moves at all, but when I have my laptop plugged in my TunerStudio gauge says that I am at ~195f.

I recently replaced the sensor to the ecu, but haven't changed the gauge one. Unless I'm mistaken, they take readings at fairly similar spots on the back of the head, so how likely is it that my sensor is just bad?

 

Can you post the year of your car and maybe the engine code as well if its a 1.8L. Hard to help with no info on the vehicle

 

Why did you replace your original sensor? I would wager the sensor for the cluster is reading correctly, and you received an ecu sensor with a different resistance curve which is giving a lower temp reading then actual.

 

My NB does this. Try turning the alternator off and see if the gauge reads normal (just turn the engine off and then the key to run so the guages read). For some reason, any time the alternator is running on my NB the oil, fuel, and temp guages all read slightly high, even though the charging voltage is fine.

 

Both the temp and oil pressure gauges are idiot lights with a needle. You really can't use their position to mean anything other than cold, normal and already puked a head gasket. Trust the ECM reading and or get a real gauge.