I noticed my cooling fan never comes on, and the coolant temp seems low. I can get it to 100C by sitting and revving 3000 rpms, eventually it gets there and the fan kicks on, but then cools back down to 80C as soon as I start driving. Is this a thermostat issue? Wondering if it is affecting the ability to set the Cat Monitor Ready.

 

Cools to 80C or 80F?

80C is okay; 80F is too cold and would start with replacing the thermostat.

 

Sorry, an F slipped into the post once, everything else was C, hope that was obvious (80F is impossible or a bad sensor, etc).

 

I have a aem digital gauge and it sits around that same temperature range in my car too

 

I have an Ultragauge that will show coolant temperature. Going down the highway it consistently sits at 171 F (77C). Sitting in traffic it will rise to about 185 F (85 C) before cooling back down. I think your car is operating totally normally.

 

Thanks everyone. Finally after 450 miles, the "cat ready monitor" is good and my car was able to smog. So not related to 78-89C coolant temp. I just thought it would run at 90C+ for some reason.