Originally Posted by Cowboy_Caddillac
hey guys, thanks for looking at my post. i think i have a sticking thermostat i was driving down the road and my trucks engine temp usually runs between 192-195 but my programmer started flashing and beeping and my engine temp got up to 215 for about 10 seconds then went down to around 200, i kept driving and couple min later it got all the way up to 235 for about 30 seconds so i pulled over and it went back down with out turning the truck off. when i got where i was goin i checked all of my fluids and everything is good. i wasnt running the air or anything and i was doing about 45mph, normal driving. is it the thermostat?
Yes it could be the thermostat.. But it could also be a water pump, or fan clutch issue as well.. If the coolant system has not ever been flushed, its very possible that some contaminants are causing a blockage at the T stat..
Start with the easiest solution first and flush the system and change the thermostat.. (Should be a 192-193 degrees T-Stat). You may just discover that the cooling system is air bound in the process..
Do the flush first......
Run a water hose to the reservoir and open the Pet **** on your radiator to let it drain it out.. Try to do it on a warm engine while running.. You can also just use a shop vac to suck the fluid out through the reservoir with the engine off. There are tons of ways to get this done....
But I highly recommend this this.......................
(Since this job is kinda messy, it's the only flush I would actually recommend you let your local jiffy lube do.) It's cheap, and their machine basically sucks out the fluid, then puts fresh fluid in, sucks it out again, then fills it one last time and your done.. It actually works really well with the whole push and pull of the fluid factor... Plus, there's no way for them to screw it up, and all the wasted fluid is their problem not yours..
Remove the upper radiator hose from the water neck and bend it aside.. 2 bolts get the water neck off the T stat, and be sure to get a new O ring gasket with your new T stat. Swap tsat and reverse your steps. Fill the reservoir and start the truck..
If the problem persists:
You can pull the serpentine belt off and spin and wiggle the water pump impeller shaft/ fan clutch to check for any play or noise..