karl delight

Ok I have heat, but not much a idle I have to get it up to about 2000 rmp then its hot go below 2000 then its just warm. It has been -19 to -5 for a week. Is this the norm?

Jamie57

Check to make sure you have a radiator full of antifreeze. If it is then you may have a partially plugged heater core.

karl delight

Ya its full. I watched that guys youtube vid on how to back flush the heater core. I'm going to give that a try. I dont think i want to use CRL however. Would just air work then do I have to replace my thermostat?

Jamie57

Why not use CRL (or CLR)? It's just going to take out the scale in the core.
It won't hurt the metal. I've done it countless times. A friend that runs a repair shop makes all kind of money doing it that way and saves his customers big dough.

mudfrog

The heater valve(?) probably needs to be replaced. I believe thats the name of it, been a while since I fooled with one. On my brothers XJ he had the same issue. No heat at idle, but heat under heavy load. He replaced the valve (the tee in front of the hoses that go to the heater core) and his started working again. There is actually a button on it that you can press to test it. Press the button and if your heat starts up then that is your culprit.

Running Free

DON'T use air unless it's under 16 psi or you'll muck your cooling system up.

karl delight

Thanks to all I'll try this Saturday its going to be much much warmer.