My 2006 nissan altima heater blows cold air when the car is idleing

Paul W

• 404 Answers
• Posted on Jan 16, 2009

SOURCE: heater bows cold when idling

Hya!
You need to bleed the cooling system.
To do this park on level ground, when cold remove coolant filler cap, start engine and leave to idle.
Have plenty of warm/hot water available, when engine reaches operating temp it may appear to boil over so keep away from coolant filler, top up with warm/hot water and wait as it may bubble over a few times before settling.
Replace cap and hopefully back to normal, Remember your Anti Freeze?
Good luck,
Paul 'W'
Oner~EDson(:0) {#><U.K.

Paul W

• 404 Answers
• Posted on Feb 24, 2009

SOURCE: Nissan Altima no cool air blowing or hot air blowing

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.

Please press the Blue button to appraise my FREE Efforts, Thank You!
Paul 'W' U.K

SOURCE: heater blows cold air at low speed and idle

I worked at a Nissan dealer for 18 months and we'd get a lot of these in. The cold heat at idle is accompanied by a sloshing noise from behind the dash - you've got an air pocket in the heater core. What we used to do was lift the front end of the car about 3 feet off the ground using the hoist and take the rad cap off. Then we'd run the engine at a fast idle (jam a screwdiver against the throttle stop to hold it fast or put a slight weight on the pedal if it's Electronic Throttle Body. Run the heater on full heat and the engine like this. You'll see the rad 'burping' as the air in the cooling system travelling to the highest point it can - the open rad cap. Top up with a 50/50 mix of coolant and water as you go. When it burps no more, you have a full cooling system and should not suffer any more "cold heat".

If you do this yourself, PLEASE use jack stands, block the back wheels and put the parking brake on!!!

answer from a Nissan mechanic, (not me)

SOURCE: 2005 nissan altima heater blows cold air when

Check your coolant level. If it is low, what you describe will happen. Water pump works faster as rpm's increase, managing to get hot coolant to heater core (highway speeds). At idle, pump is not working fast enough to get the coolant to the heater core.

SOURCE: The heater in my car will not work while in park

I have the same problem. When my dealer changed my coolant I now seem to have a stuck thermostat. They are denying they did it. I haven't changed the thermostat yet but that is the problem.