2003 Ford Escape • 130,254 miles

My 03 ford escape heater works when driving but cold when stoped, has a new radiator after a deer damage repair, if you are at park and hold down gas gets warm again, I replaced thermastat and it still does it. I did notice that all hoses are warm but 2, one going from thermastat to radiator and one of the hoses going onto fire wall. The vehicle never overheats the gauge stays in operational range, and there are no leaks, I have been told could be water pump is getting weak, anyone have a answer, im clueless. Thanks.
September 10, 2011.

It could be a couple things. First, when driving, the RPM's are higher causing the water pump to push more coolant. Make sure the system is full and there are no air blocks. With the engine cold, loosten the return hose from the heater core to see if air comes out.

Now, you said one of the heater hoses from the core stays cool. That tells me either the heater core is partially plugged or there is an air block. Disconnect the hoses and back flush the heater core with a garden hose to see how the water flows through it and how much dirt comes out.

Let me know what you find.

I havent had time to flush it out but did drive it alot today was going to go get a water pump but now seems to be working fine SO FAR, but if it does it again I will flush and post, I think it could of been some air in the system after the radiator was replaced

Sep 11, 2011.
That is a very common issue. Let me know if I can help.