I have a 2007 nissan xterra. When I stop at a light or idle, the heater blows cold air. When I increase the RPM's the heater air warms up again. What could be the problem?

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 ...

Heater only works when pressing the gas? - DoItYourself.com ...

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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.

Heater blows cool air when stopped and warm air while ...

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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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Sounds like The thermostat is stuck open, Keeping the water/coolant circulating too fast and not getting warm...

Heater core may be clogged. Try flushing it to see if water flows through freely. Also check the heater water control valve for restrictions.

water pump fins are worn, therefor you need higher rpm to move coolant faster. just change water pump

sign that the thermostat is stuck open, which is just allowing your anti-freeze to flow through all the time an therefore making it run cooler at a higher rpm or low anti-freeze level

Does your car overheat too?
If so, you could have a faulty thermostat, an air pocket in your cooling system or maybe even a leak somewhere. My truck's heat would only work while I was driving, then stopped working altogether while the engine started to overheat. I changed the thermostat, then the heat would blow hot/cold/hot/cold, I didn't realize you had to bleed the air out of the system after changing the thermostat. I did that and now the heater and engine run great.

check the coolant level possible leak at the intake manifold very very common problem on gm v6 or possibly your themostat is sticking and the increased rpm could force it open

bleed the air out of the cooling system

Hi!
It appears we have an Air lock scenario and you will need to perform a system Bleed.
Park the vehicle on level ground, when cold remove coolant filler cap, start engine and leave to idle, turn heater on full and blower to max. When engine reaches operating temperature watch and listen near coolant filler, keep clear as gurgling and hopefully a boil over should occur. Top up with very warm coolant and wait as it may do it again.
Check for heat inside vehicle if warm replace coolant cap but keep an eye on temperature gauge as the ~Air lock may have moved on from heater matrix/core so proceedure needs to be carried out again from COLD.

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Paul 'W' U.K

I live in Alaska and have had the same problem i just added more coolent to the radiator and it warmed up i installed a block heater and i leaked a bit and the coolent level got low and i would have no heat. I tryed to fill just the coolent resivoir and that dident work so i filled the radiator pumb full and that worked!! Hope this helps.