I have noticed that my heat will not turn on and blows cold when my car is idling, at a stop light, trying to warm up the car before leaving, etc. The heat only kicks on about 5 minutes after driving if the car is already been running for 10 minutes. It

Any theories, ideas, suggestions?

 

Just did this to my wife's car. PLEASE CHECK WATER PUMP!!! the weep hole on these is behind the timing chain cover. You might not notice it at first. Check your levels if it keep dropping it is the pump. Check your oil filler cap if its muddy looking its the pump. Nothing showed up in our car until it ran hot. Oil on dip stick was fine but the cap wasn't. if you just did some radiator work be sure you bleed the system correctly. If none of these is it try a back flush on the core itself. Pull both hoses use the one closest to the recovery tank and then reverse should help.