running hot...

[draggin95niss]

i ran it for roughyl 30 minutes down the freeway and thru stop and go traffic and it never got hot which before i did this it would have gotten hot....the radiator shop said it was at nearly 5% flow...so it was clogged up pretty bad...the truck did originally have dexcool in it but i flushed it all out and put green antifreeze in it....while i was topping it off it didnt seem to open the tstat at all....

 

[Z Fury]

I'm no help from here. I know that running at 1/4 on the temp gauge is cooler than the engine was designed to operate. On the plus side, the only thing running cool does is affect performance and fuel economy, but only a little (not significantly).

Maybe your temp sensor is going bad...? Maybe it is due to a fresh batch of coolant running through a very clean (efficient) radiator...? Don't know... I'd definitely keep an eye on it in the coming days though.

 

[draggin95niss]

well this still isnt fixed, its still running cold and now since its starting to cool down here it barely rises above 100, the heat never gets hot, i havent changed the heater core yet but if the motor doesnt run warm enuff then theres not point...i drove the truck 20 miles from work to home and when i got home i shut the truck off and popped the hodd and u can grab the radiatior so its nowhere near the correct temp it should be, also th eupper radiator hose is soft like it has no pressure on it...im gonna change the heater core and tstat tomorrow and flush once more and go back with green antifreeze and mix water with it....if that doesnt help im at a loss....could it be the green antifreeze not letting it come up to temp? does the dexcool make that big a difference?

 

[JollyGreen]

The anti-freeze shouldn't be the problem at all. After mine was flushed completely and the green was put in it's always run at the same temp (170). Other than the tstat I can't think of what else it would be. BTW, my rad hose is somewhat soft like your describing.

 

[GMCTRUCKS]

Glad you have a cool truck now. Hey guys when I change my antifreeze I use one gallon and fll the rest with distilled water.

 

[MOBS]

well this still isnt fixed, its still running cold and now since its starting to cool down here it barely rises above 100, the heat never gets hot, i havent changed the heater core yet but if the motor doesnt run warm enuff then theres not point...i drove the truck 20 miles from work to home and when i got home i shut the truck off and popped the hodd and u can grab the radiatior so its nowhere near the correct temp it should be, also th eupper radiator hose is soft like it has no pressure on it...im gonna change the heater core and tstat tomorrow and flush once more and go back with green antifreeze and mix water with it....if that doesnt help im at a loss....could it be the green antifreeze not letting it come up to temp? does the dexcool make that big a difference?

The antifreeze isn't your issue, you said it never warms up. Sounds like your t-stat is stuck open. My 96 has to use the grille mask once the outside temp reaches the 30's or it won't warm up completely. The engines run at their optimal temp ~200 degrees. I would suggest using a grille mask until you get this figured out, you'll enjoy the heat during the winter.

 

[chevy_man]

Which t-stat did you put in? Mine would hardly heat over 100* with a 180* t-stat. Changed it to a 195* and it now goes right up to 210* and stays there. Amazing how a 15* difference will actually make the motor temp change so drastically.

 

[Wwildman]

Ok now that we solved the problem of the truck running hot and fixed it. Now it is running too cool .
Here is what I would do if it were at my shop .
1. Start it up let it run see if it builds pressure in the cooling system if it does not the t-stat is stuck open partially.
2. How much air Flow is coming across the radiator cold from the engine fan ?
Did you use a new Tstat or the old one ?

 

[draggin95niss]

ok well ive gotten it fixed...i took out the heater core and flushed it and then i pulled the tstat and flushed the engine again with the heater lines hanging down, after that i put in a new tstat put in green antifreeze, and topped off with water...it came up to temp and it now has heat...thanx for all the input i appreciate it...

 

[MOBS]

Did you notice if the old t-stat had gunk built up around the valve or the outer seal? The gunk could've messed with the sealing properties and allowed water/pressure to go by.