My daughter just bought a 2006 Chevy Impala and it has a remote start which she of course was looking forward to going out and get in a nice warm car. But…it doesn’t seem to throw heat except when she’s driving.
Kinda defeats the purpose of the remote start? (ya, she let’s it warm up first)
Well that is not the starter’s fault. 
Of course she needs to have the heat set before she turns off the car the night before. Normally a car will provide heat when sitting, but not as much as when driving. There are several possible reasons they it might not. If there is a vacuum leak, it may not function properly, low coolant or air in the system. I would guess some cars rest the system when you turn the car off. There may not be anything you can do about that. Is it a factory remote or after market?
Thanks for replying Joseph. No, it’s not the remote start which was factory installed. The problem is even after the car has been warmed up, and they drive away the heat comes out but when they stop like at a stoplight, it starts blowing cold or cooler air. The temp gauge is it the normal range and other than that the heat works fine. It is a 2006 but with almost 100k on it. I thought of the thermostat but the heat still works the rest of the time. Any other thoughts? Thanks!
Is the cooling system FULL? Even if full air may be trapped in the heater core or the plumbing.
Thanks for responding Rod. Not sure if I mentioned, the car has 100k on it.
I didn’t think the car would need any coolant but guess what? The coolant tank was empty so I added coolant to the radiator until full with the engine running, and then filled the tank. Damn thing still blows cold at idle and when she stops at a red light etc, but blows hot while the car is moving.
I’ve never heard of this before…usually it works or doesn’t.
I’m still stumped! Any ideas? Thanks!
I think there is an Issue with these cars. I run an automotive repair shop and we have had three in the last few days doing the same thing, We service a large fleet that has several of this type of car. We have topped off antifreeze and replaced the thermostat and they still have the same issue. In talking to the leasing company they are having reports of this in several areas, I have checked with GM and no help to be had there, If anyone has any ideas please pass them on.
One thing not considered yet is vacuum. Some cars the flap that diverts the air is controled by a vacuum. At idle there may not be enough vacuum to keep the valve open…thus letting in cold air.
We need to back up and end some of the speculation here. First thing that needs to be done is to see if the heater core inlet and outlet hoses are hot. If so, we can at least assume that it is not a coolant problem but a problem delivering heat from the core.
I suspect that Mike is right and it is a matter of a door in the HVAC system closing due to a vacuum problem.
Hi gang…problem solved! The coolant level was very low and actually took almost 2 gallons of a pre-mix solution. In an older car, I would have checked this as a matter of fact but because the car is new…except of course the 100k on it. This was a salesman’s car and I was surprised it was so low…which of course leads to the next question:if I don’t find coolant in the oil and it doesn’t seem to be leaking, where did it go? The car was purchased in South Carolina and my daughter says it never overheated and/or the temp gauge was always in the normal range.
Well, she has heat now! Thanks for all the replies!
We are having the same problem. I have a 2006 Impala - 3900 V6 engine - with 39,500 miles, and it blows cold air at an idle. According to the mechanic, they have detected carbon monoxide in the coolant, and the coolant was low. We cant figure out why there would be carbon monoxide in the coolant, nor can we figure out where the coolant is going. Cant seem to find any coolant leaks. The mechanic thinks it might be a head gasket… any thoughts? I’d appreciate any feedback
If you have CO in the coolant, it’s most likely a head gasket, or potentially a cracked head, The missing coolant is leaking into the engine and being burned. If it’s bad enough you might smell the coolant in the exhaust.
We cant smell the coolant burning off in the exhaust… is there another way to tell?
Finding CO in the coolant is pretty conclusive. If the coolant isn’t leaking of going into the oil, it’s being burned in the cylinders. I assume your mechanic is recommending that the head gasket be replaced?
Two GALLONS low? Your daughter is lucky she didn’t toast the engine.
First step: replace the radiator cap. Then a cooling system pressure test.
indeed he is recommending that. However, with all the problems it seems people are having with this “no heat” issue… i dont wanna fork out THAT much money if that isnt going to fix the problem. Just trying to cover all bases before I max out the credit card or fill out a loan application… hahaha
The no heat issue is probably due to the low coolant, which is due to the gasket leak. I assume that your heat would be OK (for a while) is you refilled the coolant system and got all the air out.
Check your oil immediately, if not sooner. Burning antifreeze is bad enough (it’ll destroy the O2 sensors at a minimum) but if it’s getting into the crankcase via a bad intake manifold gasket, it can destroy the engine bearings in short order. Then you’ll really be singing the blues…
Going to go out and make sure it’s topped off in just a little bit. Will let it run and what not to see if anything changes, and will keep everyone posted. Thanks for the help all!