Tasks long time for heat

[mrriverrat1]

The last few days I have been had little or no heat intermittenlyMostly at start up inthe morning I warm up car in garage for 20 minutes with heat on low when I get in it's blowing cool air, I rev motor it starts get get warm then cools, I Drive down the road about 25 mph it gets hot then fine til it shut it off and let set for a few hours, I live in mIchigan and the weather has been cold,the last two days I have had no Problem, I check coolant was fine car is 2004 vibe with 78k on it.I feel it's the thermostat sticking my Guage reads fine

[star_deceiver]

Your temp gauge reads normal and you still have no heat. I'm assuming that your fan works.Your heater core is probably clogged or there's air in the coolant system that's preventing hot coolant from getting to the heater core.If your thermostat went south then your car would either overheat or not warm up at all (gauge barely moves).

[tribalman]

if you have the fan blowing while the car is warming up it will take longer for the engine to get to operating temp. the heat is provided by the engine and if you are taking that heat to warm the cabin it will take longer to get warm. if you just run the car for 10minutes with the heat off by the time you get in the engine should be nice and warm to be blowing warm air. i just start my car and drive off(assuming windows aren't frosted on the inside). takes 5 minutes to get warm. i only use the heat when i need to defog windows, otherwise it's off

[knightrace]

I'm having a similar problem with my heat. I've noticed that when I stop at a stop light, the air coming out of the vents begins to turn cold. Once I start driving again, the air out of the vents warm-up again. This is the strangest thing.

[Bedlam]

sounds like air pockets in the coolant. Level will read fine since the air is taking up space. The system should be burped and topped off. Higher engine speeds push more fluid through the pump and get some hot coolant moving and warm air blowing. At idle, there is not enough flow to overpower the pocket and the air goes cold again. It's the first place i'd check and a cheap fix if you can do it yourself.