weird overheating problem

[TURBOSPEED]

i been having problems with my 03 v8 LS , it overheats when driving , but if i pull over and let the engine running in park , temp goes down to normal , i bleed the system for air following the intructions but dont know if i could still have a air pocket.

 

[joegr]

Well, did you get air out when you bled it?

 

[TURBOSPEED]

did the whole process all over again , if i leave the heater on max i wont overheat but as soon as go to the 24c step i will start to slowly over heat and after 5-10 min it will overheat.

perfect idle no missing. oil seems fine.

 

[joegr]

Does the cooling system pressurize?
(Feel the hoses when the engine is cold, note how easy they are to squeeze. Once the engine is at full temperature or overheating, try to squeeze the hoses again. If you can, then the system didn't pressurize.)
If it doesn't, then you have a leak somewhere and you will have to fix that before you can test anything else.

If it pressurizes, then my best guess is that you might have a clogged radiator. I don't think it's the fan, because you said it cools off just sitting at idle and overheats while driving.

 

[ground_zero298]

hose should be hard when the t-stat is closed. Should be able to squeze it when it's hot and open. Almost sounds like the fan not running at max speed.

 

[#1fordfan]

hose should be hard when the t-stat is closed. Should be able to squeze it when it's hot and open. Almost sounds like the fan not running at max speed.

It's the other way around. hard when the T stat is open, soft when it is closed.

 

[ground_zero298]

maybe mines backaswards, guess i better look into that, lol

 

[tireman]

overheating while driving

Overheating usually is do to not enough air flow across the radiator to release the heat from the liquid in the radiator. If you have an electric cooling fan, the fan control or fan may not be working correctly. Too much antifreeze in the system, thin it out with water. Maybe you have trapped leaves and debris in front of the radiator, remove the plastic cover and look down in front of the radiator. Maybe water pump is shot. Check for leaks too, around the degas bottle, that pesky thing cracks and drops pressure when hot, then closes back up when cool.