My 2007 equinox keeps overheating and I’m going going driving two blocks and blows cold air through the heater

SOURCE: Heater blows cold air when idle

Sounds like you may have a partially plugged heater core. You could flush this out separately, from flushing radiator & engine block. Diconnect heater hoses going to your heater core and clamp off, so not to loose coolant from engine. Now hook up separate hose to one side of heater core pipe and flush out with typical garden hose. Repeat procedure on both heater core inlets. Reconnect original heater hoses and test difference. You may have to add an additional litre of antifreeze. If this don't work i suggest changing heater core. Good luck.........Ron.

SOURCE: blowing cold air

I had the same problem that I just fix by flushing the heater core out with a hose.   take the two hoses off the fire wall and put the water to it and let flush.  my heater is putting out 150 dg. F  of hot air.   I'm so excited!  i will stay warm now.

Johnny Brown

• 5763 Answers
• Posted on Oct 06, 2009

SOURCE: Toyota Celica gts 2000 blowing cold air when heater is on.

nothing try back flushing heater core, they clog up due to litle water preasure,you might want to flush cooling system if you already havent, hope this hleps.

SOURCE: When driving, heater blows warm air. When idling, cold air.

It sounds to me like you have a plugged heater core, or one that is beginning to plug. With the engine running, carefully feel the two hoses that lead from the engine into the heater core in the firewall. If one of those hoses is colder than the other one then you heater core needs to be replaced. This involves removing a bunch of stuff under the dash. Sometimes it's pretty easy and sometimes not. Start by removing the glove box and you should be able to see the plastic housing for the heater core.

SOURCE: 2008 ford f250 6.4l diesel, heater works one time

Feel the heater hoses when it blows cold air--they should be quite hot when the engine is up to temperature. If ok, then either the control center in the dash has a problem or an air-duct vacuum-controlled-valve has a problem with sticking in one position. The truck is too new to have bad vacuum lines, but one may have a kink that is causing a problem. Check around the engine and the dash control panel for a loose or split vacuum line.