im not sure what to tell you. i mean heat is a byproduct of energy, so it has to be going somewhere. if you run straight water it can cool an engine too much, if you run a low temp thermostat it can cool the engine too much, if you run a high volume water pump it can cool it too much. with all that being said theres pro two water pumps for your truck. one for ac and towing the other without. but even with a high volume water pump if you block the rad off it should overheat. did you drive it with it blocked off? the heat has to be going somewhere.

 

Yes I drive with the grille covered

 

Check your Radiator cap... make sure it's on correctly, tight, and the correct pressure for your truck. Had lots of problems with that myself. Rockauto.com is best place to get a "stock" direct replacement (ACDelco).
Also, did you completely fill the radiator, overflow, and heater core the proper way? I found this very interesting with my S10 4 cylinder... Temp never went above 150 F. I had similar, new engine, radiator, coolant overflow tank, hoses, water pump, heater core and hoses. I did alot of "late night reading" and found a youtube video of "Eric the car guy" video... Learned something new about adding coolant to vehicles... Temp is now 205F and stays there!
Scott

 

Thanks I'll look into it, and what's the "proper" way to fill up the cooling system, I always just thought u fill it up and bleed out the air and good to go
​​​

 

I just put a failsafe thermostat in my 1998 K-1500 Chevy. The old one was a 195 F unit, but was only heating up to 179-180 F. So far its worked well at 192 F. With a 22-year-old pickup, the old standard thermostat lasted a long time,

 

CG2003, there is a funnel that stays in place into the radiator, it' s about 40 bucks at advanceauto/ AutoZone. Fits all makes and models with supplied pieces. Fill overflow tank, secure funnel in place. Start vehicle let it run adding coolant to funnel so there is no "gaps" or air in system. When engine is warmed up turn on the heat or defrost. Keep adding fluid until the coolant is in the funnel and not going down.
all total this should take about 20 minutes of engine running. The funnel is a "no spill" so you can "shut" the valve and put remaining coolant into container. The newer cars 25 years or so now require this methid so as nit to have air bubbles in the system... I think this and a bad cap were my problem.
this methid also got rid of the " gurgling" noise I had in the cab of the vehicle.


here is a pic of the funnel... Made by Lisle. Good luck

 

imo air in the system would cause it to overheat as air wouldnt heat up like coolant and open the thermostat. also this way (with the funnel) isnt required and many models have bleeder valves on the thermostat to bleed off any air. ive bleed the system by pumping the upper rad hose with my hand to get fluid all around it. theres prob a few different ways to burp the system as some will just drill a small hole in the thermostat or taking off the upper hose and maybe even this funnel.

 

Irish, I agree... Ive tried drilling the hole in the thermostat, I know the pump the upper hose trick as well, and all the "old school" rad caps had the lock handle... Drove many miles with the cap "popped" to prevent the overheating. For me this funnel finally worked on my 1995 s10. All the other tricks didn't do it for this truck. But you are correct about " Burping" the system to get rid of the air... By filling the funnel and letting it run for a while the air works it's way out then remove the funnel.... And trust me... The first 4 cylinder I have rebuilt and it has kicked my butt! Lol. Right now the stupid thing has a major electrical short that I can't get a handle on...
Scott

 

I filled using the same method as using the funnel, except I didn't use the funnel, it just made a huge mess, but it worked.

 

Has the temp come up any since you did this?