TRUCK WONT WARM UP!!!!

[rtsol]

1992 k2500 5.7. years ago when i put the new engine in, i added water wetter which i thought would run a little cooler being that it a little hopped up. im driving the truck more now and cant stand how the temp just wont go above 1/4 the way up the gauge. thermostat looks good. water wetter with the old coolant gone. ill let it run for 30 min parked, the temp is low, heater wont heat and heater and radiator hoses barely warm. dont know what the hell is wrong with it. btw a few days ago i opened the cap(cool to touch) while the coolant was warm and alot of air pressure escaped, soon after the cap became super heated then cooled back down rapidly. any advice? thanks!

 

[SCOTTYINWV]

Change the thermostat. I wouldn't take one out to see if it looks good without replacing it. It's like $5

 

[jrollings]

yep I agree with the above. Might as well replace it. See what temp is stamped on it. Go with 195* and throw your water wetter in it if needed.

 

[someotherguy]

Replace thermostat with correct temp 195F and only a good brand, Stant Superstat would be a good choice. Drill a couple 3/32" holes in the flat area being sure not to encroach into the gasket area; this will help bleed out air pockets faster. Drain whatever you've got in there and fill with 50/50 coolant/distilled water mix. Park on an incline - nose up - use ramps, jack stands, or even just a steep driveway, whatever will allow you to get the front end higher up safely. Run with the cap off and watch that it burps out air, refill as necessary, do this a few times then cap it and run it. If your cap look sketchy then replace it too.

If it still won't come up to temp after this (and confirm with an IR temp gun aimed at the intake below the thermostat; don't trust the gauge) - you probably have a stuck fan clutch making the fan run full time.

Richard