Cant figure this out...i noticed a couple days ago that if i'm stoped at a red light or at idle...the heat goes kinda cool, but when i step on the gas it heats right up...so i replaced the thermostat (thx mygreenmax94 for the pics) and did a flush...when i was in the repair shop it seemed to clear it up...and when i drove around after for like 10 mins it was good, but then it started to happen again...anyone have any ideas??? thanks

 

try letting the air out of the system. There is a screw on the motor (drawing a blank where now since I dont have any GXEs to look at but think its around the intake manifold) that you can loosen up to allow all the air to get out of the system. You just open it up and keep it open a little bit after your water/AF mixture comes out and then close it back up.

 

we did a flush ( this was all done in a shop with me and a machanic)...there would still be air in the system??? thanks

 

yeah probably. Its either something like that or sensor problems. I doubt that if you have a new tstat that the car is actually cooling and warming up so fast. Then again I have never really chases any temp. issues like that.

 

when i say heat..i mean the heat going into the car...like when its cold u turn on the heat, not the engine temp.

 

oh ok

maybe the heater core. Maybe someone that has had this problem will be able to help out.

 

Anyone have any other ideas??? thanks

 

My ford van has this erratic temp gauge thing before. It was air in the system.

 

my heater problems were due to my heater valve located in the middle of the firewall at the top. it has some vacuum hoses going into it. my symptoms were different than yours though. i just moved the vacuum hoses around.

 

so no ones had this probelm before...i'm frash out of ideas

 

Have you made sure the heater core lines going into the firewall are hot when the engine is warmed up?

 

just for the heck of it try the air release. It doesnt cost a thing and takes only a second. I have heard others say that air in the system will cause crazy things like this. If its not air in the system then there is a problem with the core or maybe even the water pump who knows. Try to release the air and see what happens since that is so easy then move on from there. And yes there could be some in there after (especially) a flush.