94 360 Running Hot
 

I recently completed my 94 auto To manual swap, and have yet to update that thread, but I'm getting really passed with my current situation. I had the motor out and did lots of things to it, including a new water pump and thermostat, and all brand new coolant. I put it all together, and once I was finally able to start the truck, I added the coolant, and let the thermostat cycle. It got about 3/4 of the way up, and then slowly moved back down to 200. But only that time. Now I'm faced with it running hot. It only took about 15 of the 20 quarts, I didn't drain the heatercore but I'm not sure if it even takes 3 quarts to fill that. It runs about 3/4 of the way up the gauage on the highway, and in Town it fluctuates a little above 200 and 3/4 of the way up. I really want to get it so it stays at 200 all the time. I've tried burping it but I can't seem to get any air out at all. I did drill a hole in the t-stat for bleeding, but I'm getting pissed that I'm not getting any air out. Any help would be appreciated for this. Thanks.

What brand thermostat did you get?

I would also be tempted to get an IR thermometer, and see what the radiator looks like. Did it run hot before? If not, I would simply replace the thermostat.....

Stant super stat 195.

Ran at or barley above 200.

Would it be possible there's still air in the system? If so how would you say I go about bleeding it out?

After driving it for a while, it should purge the air from the motor. There may still be some in the heater core, but, that shouldn't really affect engine temp. (just heater performance)

If temp runs higher in town, but, seems ok on the freeway, could be the fan clutch is going bad.....

Is the serpentine belt routed properly.

Just replaced the fan clutch, cause it needed it anyway. Didn't change a thing. Still runss 3/4 of the way up the guage in both town, and highway.

I also put a new cap on, and immediately after I got back home from a test drive after getting her hot, I opened up the radiator and it didn't go whoosh. How hard are the hoses supposed to feel? It kinda seems like it's not building up pressure.

I think the caps are like 16-18 pounds.... so, if there is no pressure, you have a leak somewhere. Also, opening in when it's hot can be extremely hazardous to your health..... Don't do that. :D

Radiator full?

How old is the pump, and thermostat?

The pump and thermostat are brand new, like I said I used a stant super stat 195 degree. After the drive home from work I felt the hose, and it seems to be pressurized, but I went to borrow a pressure tester from the auto parts store and will see what that says. If that tests okay Then I don't know what else to do. It acts like there is still a bunch of air in it, and I have no idea how in the hell its still in there.

Any air still trapped should only be in the heater core. (it is notoriously difficult to get it all out.) Check the connection at the temp sensor for the gauge. Should be on the passenger side, front of the intake, right next to the heater outlet hose fitting.

I also changed both temp sensors so I know they are working properly. I know the barter core is a pain, and for right now the air in there is okay with me, mostly because it's about 90 degrees here every day :D. Air couldn't be trapped anywhere else? I have been driving it for about a week, so I don't know I feel that would bleed it or not.

I chased a problem like this for a while. When the truck was up to temp I felt the radiator and about two thirds of it was cool to the touch. Turns out the previous owner used a lot of stop leak and it plugged the radiator up.