donaldj79

Thanks Trevor and Old Peter!! Trevor, when you say Air Lock...is that the same as bleeding the system? I saw the mechanic open/loosen the bolt on the thermostat housing while filling up the coolant reservoir. Said he was bleeding the system. is that the same thing? With an Air Lock, would I be getting NO heat at all or very little heat? Car Temp stays perfectly in the middle. I did the the Diagnostic mode on the Climate Control, NO codes stored. Heat did work when I first got the car. Didn't go bad til I put the Bar's Leak in the system. Thanks Again for you help in figuring this out with me!

I have read the posts/threads regarding no heat, but I have somewhat of a unique/dumb situation. I bought a 2001 XJ8 with 78K miles . When I bought the car, everything worked including the heat. But it did have a small coolant leak, just couldn't determine where the leak was. After driving the car for awhile leak got worse and i put a bottle Of Bar's Stop Leak down the coolant reservoir. Bad move!! At first everything was fine. Then the heat went out. I had the car looked at by a mechanic Thermostat housing was bad. Had it fixed. Still no heat!! Figured I had clogged something up. Had the system flushed, all hoses removed and checked for blockages. And the Heater core was flushed with water until it was clear in both directions. Also had the AUX heater pump and Heater Control Valve removed and taken apart to inspect for blockages All Clear!! Still NO HEAT! I have disconnected the AUX Heater Pump, so that I can feel the difference when its connected and running and when it's not. It's definitely running. I can't tell how warm the hoses are by the heater core/heater control valve because it's so much engine heat in that area. But i know the hose from the AUX heat pump is Luke warm at best. All other hoses are hot. Not sure how to test Heater Control Valve, but from what I read they don't go bad too often. What am I missing? Is is possible I could have messed the pump up with the Bar's Leak? Only thing we haven't done is remove the Heater Core from the car. But like I said, mechanic "said" he flushed it. I get no heat when i idle the car at 3000 rpms or when I drive down the highway. I welcome any and ALL suggestions. Please chime in. I hate to just start throwing parts at it.