Hi,

I had my 97 4.6L idling for about 20 minutes today inside a warm garage. I had a SNAP gauge hooked up to check on up codes and such. There are no codes.

The ECT reading on the snap on gauge was reading 180F and the infrared reading on the thermo housing was reading 150F. The coolant gauge inside the truck has always been on 1/3 of the way up.

Is this normal?

The fan was running the entire time with the hood up when testing. I did replace the thermostat last year from AutoZone, but I don't remember what temp thermostat it was.

Thanks,
Frank

 

That is probably right because the temo is 194 degrees in my truck.

 

So I swapped out thermostats yesterday.

The old one was rated at 195, but might have started dying.
The new one I got did not fit correctly since the o-ring rode around the thermostat, i'm guessing it is for the 4.2 and not the 4.6L. So I took of the o ring and put the old o-ring above the new thermostat (you can see the old o-ring in the back ground of the first picture.)

The temp now reads 190-195 F.

Anything more I can do?