2004 Infinity G35 heater

The heater on my Infinity does not blow hot air when the car is idling. The fan always works, but not hot air when at a stoplight. When I start driving it starts to blow hot air again, but as soon as I start slowing down the heat turns to cold air.



Does anybody have any suggestions or ideas?



Thank you

The first thing would be to check the coolant level in the radiator. If it is low, it will have these symptoms. Secondly would be air in the coolant system that needs to be bled out and last, if you have a head gasket leak allowing combustion gases into the cooling system, it can cause an air bubble that is overcome only when the engine revs faster. Keep an eye on the temperature guage but most likely low coolant, so check for a slow leak somewhere too.

Thank you for the suggestion. You were 100% correct. The coolant was low in the radiator, but the coolant reservoir was full. I suspect that the last time the coolant was changed, they must have not taken the air out of the system.

Thank you for the suggestion.

Check the level often in the radiator over the next couple of weeks. You may have a small coolant leak. It may the case that you did have air in the system from the last coolant change, but I would bet on a leak.