Heater not working

HARRELL96

MEMBER
2003 PONTIAC MONTANA
180,000 MILES

Heater blows cold air most often. Occasionally it will blow hot air but changes back and forth while driving or sitting still. Today the van's temperature hit the 260 mark and stayed there, so, I added coolant and no change. Replaced the thermostat and no change. What am I missing?

Friday, December 7th, 2012 AT 9:05 PM

2 Replies

DRCRANKNWRENCH

MECHANIC
3,380 POSTS

Well the coolant should only reach 206 Degrees F when thermosat is fully open. You may have air in the heater core or a larger bunch of air that needs to be bleed. To fdo this;
Let the car cool off and reove the radiator cap. Get some 50/50 radiaotr and distilled water mix.
Trun the heat control to the highest tmeprature setting.
Allow to reach operatin temperature and top off readiator and reserviour.
See if that helps.

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Monday, July 10th, 2017 AT 6:30 PM

XJSHEN

MEMBER
246 POSTS

Thanks! The compressor is leaking, and as you said air in the heater core or a larger bunch of air in the system that needs to be bleed. I know internal coolant leaking on my car after dealer repaired on the coolant out leaking. That may caused boiled coolant in the engine and produced air in the system.
Your bleeding method is helpful! I will do that.
Again thanks
Steven

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Monday, July 10th, 2017 AT 6:30 PM