car overheating, need help

[misfortune]

So we changed my aux fan, and rebled the coolant system. I'm driving my baby again and its just a roaring good time. I tore off a couple times down the road and I'm feeling great. I hit the highway for some more fun, (with the AC cranked for testing purposes) and it begins again. The car overheats when I'm at highway speeds. In the city its ok. At a stoplight or whatever, it begins cooling off. If I turn on the heat, it cools off a bit.


Why? Is it low on coolant? Right now, its cooling off. When its cool again, I'm going to check oil/coolant levels. The engine is at 100% still pulling strong and torquey down low. Maybe I need better coolant? I'm so confused and frustrated. Please help, I'm so damn tired of driving that F150. Such a soulless vehicle.

[BlueM60]

Im not sure what youve checked already but heres a couple ideas:
-The small little return hose from the res. to the radiator.
-Possible headgasket situation? Any coolant smeel from exhaust or excessive pressure in cooling system?
-Im assuming water pump is new?
What all has been done already?

-Ben

[misfortune]

Im not sure what youve checked already but heres a couple ideas:
-The small little return hose from the res. to the radiator.
-Possible headgasket situation? Any coolant smeel from exhaust or excessive pressure in cooling system?
-Im assuming water pump is new?
What all has been done already?

-Ben

• Water Pump is new
• Tstat is new

What about the return host from the res to the rad? It was leaking, I *might* need a new one. Its connected and not leaking now as far as I can tell. The HG is good as far as I can tell. I can smell coolant when it gets really hot.

[moreno3163]

How well did you bleed the system ( sometimes you have to bleed the system a number of times). Sometimes there is still air in the system and it will continue to cause the car to overheat. I had the same problem and just bled the system about 20 minutes.

[Blitzkrieg Bob]

you have trapped air in the system.

try again with the heater on, the car parked front end up a hill or ramps to elevate the front.

If you have any blind plugs on the top of the water neck try to remove one while the car is cold and pour coolant into it to fill the head.

[Jon K]

did i read that you said you can smell coolant in the exhaust?

[misfortune]

no, maybe I shouldn't have said that. I can't smell coolant when I'm driving the car, nevermind.

I did when I had a leaky hose from res to radiator.

[BlueM60]

I agree its very possible theres still air trapped in the system. the reason I mention the small return hose is that its very common for it to be totally clogged somehwere in the line, causing all kinds of wierd overheating issues.
If its leaking, replace it anyway. If it can be salvaged, try blowing through it with compressed air and see if any crud comes out.

-Ben

[632 Regal]

I'm not sure but did anyone mention bleeding it again, and on ramps or up a hill? those be some buggy bleeders.

[Blitzkrieg Bob]

can I go to recess now ?