When I turn my heater on it only blows cold air and never gets warm, also my temp gauge shows temperature rising the longer that it runs. What could be the problem? My car is a 1999 Pontiac Grand Am

heater blows cold air idle chrysler 300 Questions & Answers ...

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Find solutions to your heater blows cold air idle chrysler 300 question. ... blow warmair for a few mins then back to luke warm. i replaced thermostat ... HEAT BLOWSCOLD AIR WHEN IDLING ONLY GETS HOT WHEN START DRIVING ... About 15 minutes after driving the diver side vents start blowing straight cold air but the ...

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Nov 3, 2011 - When I press the gas, the air from the vents is nice and hot. .... So am Idriving a car with a ton of problems, or could the power steering ... Just anotherquestion, when warmed up does the engine temperature ... When the heater is on and I'm not pressing the gas pedal, luke warm air blows from the vents.

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RedditFeb 12, 2014 - Heater blows cool air when stopped and warm air while driving 2008 Kia Spectra (self. ... just fine but appears to blow cool air when I was stopped at a stoplight. ... My temp gauge would also be pegged high when at idle / low RPM. ...thermostat only blocks coolant going to the radiator, and the heater core, ...Missing: 300m ‎luke

Why is My Car AC Blowing Hot Air? - BlueDevil Products

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It sounds as though the engine coolant thermostat is stuck open or worn out preventing the engine from warming up properly.

I am wondering if the temperature gauge starts to rise when the car is stationary with the engine running for extended periods. If so it is probably the thermostat that is faulty.

There are many different temperature ranges of thermostats. The old one may have been a 165 degree thermostat. The new one may be a 195 degree one. You will then notice that the gauge will run higher than it used to.

The dash gauges are notoriously inaccurate. But it is possible that the thermostat is stuck open. Does the upper radiator hose get hot after engine warmed up? Also feel both heater hoses-when engine is warm, both should be hot-indicating the coolant is circulating through the heater core. If heater hoses are hot, and you still have cold air, the temperature blend door on the heater case may not be operating.
Try a new thermostat and see if engine warms up faster and better.

sounds like water pump is broken

Your temp sensor has nothing to do with your heater. The temp sensor needs coolant in order to work properly. So first check the coolant level because if it is low your heater will act the way you describe. Once the coolant gets low enough the heater will blow cold. Another possibility is the radiator cap. After the engine has warmed up it expands when it cools down it contracts. As it is contracting if the cap is weak air can be drawn into the system and cause air pockets to form and will cause the same problem

there should be a temperature door, but I don't know if there is a cable or if its electric. turn the temp knob, if it feels like it moves anything? I dont have a diagram here at home, but will monday/

check coolant level ,must be low ,chck for coolant loss

you have air trapped in the cooling system. A good indication is that one or both of your heater hoses going into the heater core are cold when they should be hot.
Park facing uphill, raise front of vehicle so radiator cap is higher than top of engine. (You want bubble to get to radiator and out the cap.)
Leave cap on but loose, so bubble can purge.
Turn heater on.
Fill radiator and reservoir with 50/50 mix of antifreeze.
Start engine and run at about 1500 roms until the engine warms up and thermostat opens.
You will know themostat opens when top radiator hose is hot indicating coolant is flowing.
Shut off engine.
Fill radiator and reservoir. Install cap.

please Rate as fixya if this works. good luck

Check to make sure your thermostat works right by monitoring the warming up of your engine. With a completely cold engine, start and run the engine for a few minutes, then put your hand on the top radiator hose to monitor if and when it gets warm as the thermostat opens more and more and note the gauge reading( if it works) the top radiator hose should be unbearably hot within 5-8 minutes. If the therm. opens right it should close right aswell, staying open a little while eventhough the radiator may have cooled may be what you are experiencing causing the rapid cooling and is nothing to worry about. The Hose should not get warm very soon after starting the engine. Regarding you gauge, lets take one step at a time, verify proper op. or the therm.