[Mike94Z]

I recently had all the wiring and new sending unit installed. It would get up to around 190 while idling but then drop to about 150 while driving. I changed the t stat thinking maybe it was stuck open. No dice. What could cause this and how do I fix it?

 

[shoebox]

Could be the gauge, wiring or sensor. Sometimes people have issues with the sensor other than the GM one. You should also use a scanner to compare the gauge reading with what the PCM is seeing.

testing info

 

[Mike94Z]

Thanks for the info. I may just put an after market gauge on it if I have to