Hey I'm hoping to get some help with my overheating issue. Just this morning my car started running hot. If I kick the heat on full blast it seems to settle back to normal-ish but still running slightly high. Any ideas??

 

Fan coming on? Could be fan,themostat, or head gasket. We need more info

 

Car? Engine? CEL? Info man. Check the obvious though, do you have enough coolant? And like Dc4 said, fan coming on??

 

I just noticed it on my way to work. Pretty sure the fan is coming on and it has coolant. I had to disconnet the hose that runs from the thermostat to the head the other day to access the harness behind it. Could there just be air in the system?

 

Why would turning the heater on make it retun to normal temp?

 

Helps to circulate coolant.

You need to see when it runs hot, driving or idling or both?

 

It`s possible..bleed the system and get all the air out and see if it still overheats..

 

Ok just got a chance to look at it a bit. The fan is kicking on. It's only getting hot while running, not just idling. The upper radiator hose swells slightly and very hot. The lower hose appears normal and has pressure. Once it cools down I'm going to check the coolant level. There isn't anything in the overflow reservoir. Any thoughts?

 

Hot while driving? I suspect bad radiator.
Did you bleed the air from the system?

 

air in your system......... especially if you just pulled a hose loose.
the res being empty too?? your cooling system was compensating for the coolant loss
top off the radiator and the res.

 

Alright hopefully that's the only issue. I'll try bleeding the system and see where that gets me.

 

I agree with grumble. Suspect a bad radiator. Air in the system in my experience has never really caused overheating issues, just idling issues. If you car idles fine then air wouldn't be the problem. Also your radiator cap could not be sealing properly or the gasket could be bad and not maintaing proper pressure through the system.