Hey not sure if this is where im supposed to post but here i go. I have a 04 g35 sedan i bought last year. when i first bought it the heat was working really good , now when im driving it blows hot air but at a stop its turns cold.. Ive changed the thermostat an tried the burp valve an still nothing. Im in canada an its winter an im freezing to death haha.. help me please..

 

you have an air bubble in the coolant system

all you should have to do is bleed the coolant line and refill with more if nessecary

 

Ive tried this method already an still doesnt work.. even had it hoisted at an angle trying to get the air bubbles out.

 

I would try again. The only easy fix I know if is the burp. There was one time I had to burp mine 3 times to get the air out after a coolant flush.

 

Have a look at the rad cap and rad hoses for suction indications. I was starting to get some gurgling sounds in the cabin and it ended up being a defective rad cap.

 

replace your thermostat, old one stuck in open position

 

i see lots of thermostats going now that the cars are getting a little age on them, and its probably not stuck open its probably stuck shut, air not running back through the lower tube, with car running and fully warmed up touch your lower radiator hose, i bet you its ice cold, while your upper is aprox 160 degrees,

 

Things I was told:

1. Air can only get into the system if it has ever been opened... but would not happen all of a sudden, unless its a headgasket failure.

2. Water Pump may be going and when the car is not under a load, it may not be spinning properly and that is why there is no flow.

3. Thermostat is fine, if the temp gauge reads just slightly under 1/2 when the car is warmed up and does not fluctuate.

I hope my car does not have a headgasket issue, or a faulty water pump... if its the thermostat, that is a quick & cheap fix - but what is it?

My car has the same issue as many of you have. When driving it is fine, but when you come to a stop - cold air starts to blow.

?