I just got a 1996 Chevy K2500 Suburban with the 7.4L and on the way home from the dealer, I noticed that the temperature gauge does not seem to be working. The truck hadn't been run in about a month, and I did hear some gurgling sounds coming from the heater core. I had the dealership add some more coolant before I left the lot, and that helped to ease most of the gurgling that I heard during the test drive, but I still heard a little more, and also noticed the temp gauge did not seem to be warming up, The gauge stayed stuck down around 110. I looked to see if any wires were unplugged around the thermostat area, but everything seemed to be connected ok. All of the other gauges seem to be working fine. Any ideas?

 

Welcome to the forum...
My first guess would be a bad thermostat... its probably stuck open...

 

Times 2..........don't buy a cheap one, their no good. JMHO
david g.

 

3 of 3, it's unanimous.

 

Update: The temp Gauge does work, but I confirmed this morning by driving it to work, and the heater never did warm up, it is obviously the thermostat. I'll iave the check all of the hoses and everything before I replace it with a new Genuine GM OEM Therm. I'll boil it on the stove first to confirm that it works. Thanks for your posts! Everything else works!

 

No need to boil on stove. Your symptons would be caused by a stuck open t-stat. And it doesn't have to be open very much to not heat up. In the winter time in Mpls, the t-stat on my '68 GTO was stuck open about 1/16" and the needle didn't budge.

 

Thanks for the reply and info, but I meant that I would boil the new one before I install it to confirm that it works.