I hope this thread continues. I have a 2009 Chev Uplander that has the heater problem. There are no pressure problems. There are no leaks. There are no cracks in the head or bad gaskets. But in mine there is some way that air is getting into the lines. I have purchased a kit that "burps" the lines. It works well and I will get good heat for about a week after the burp. Then I have to do it all over again.

I have not changed the radiator cap.

Minnesota Winters can get brutally cold!!!!

P. S. If you have to put the air conditioner on to get heat it would seem to me that the hoses were put on backwards.

 

If air is getting into the lines then you have a "crack, leak or gasket problem" somewhere.

What kind of kit are you talking about that burps the lines??

How long have you owned this vehicle? Did the heater work well in previous years?

Good luck.

 

check the heater hoses for kinks, the heater core is located higher than it as should be. any kinks and it does not get the required flow.

check my other threads. i have already dealt with this problem. was solved by rerouting the heater core lines.

 

If you are having to burp air out of it weekly, you have a leak somewhere. I heard numerous times from the first dealership that I had no leaks. I never had puddles of antifreeze underneath mine and since you are burping it every week you can't tell how much fluid you are having to put in to replace the air. The first dealership burped my car repeatedly because they thought they got air into the system when they replaced the thermostat. I brought mine to another dealership and they pulled the plugs and put pressure on it over night when it was cold. In the morning they found the puddle. It did not leak when they just put pressure on the radiator over night. In regards to the AC comment. I still have the temp (the 2 red roller ***** in the middle) on hot and the fan setting on MAX AC.The dealership mechanic said it is recirculating the heat from in the car past the heater core. Taking warm air and making it warmer like your AC would do if you had the temp setting in the cold. Also, have them pressure check your radiator cap and make sure it holds pressure. You said you are from MN as am I. If you are near Rochester I suggest you bring it to Clements chev dealership near the mall in Rochester. The service managers name is Dave. They just finished working on my van so they should be able to help you. If you can't get there I suggest you have their mechanic call them.

 

Would there be a leak at the siphon line from the overflow reservoir? When the engine is cooling down the liquid from the reservoir that is going back into the radiator may have a leak in the tubing line and create air that go back into the radiator. My 2009 uplander never had any issues for heat and the climate here is very very cold in winter.

 

Hi capucine,

Hopefully you'll get some helpful advice here for fixing your vehicle. Please let us know if you need any assistance locating a part for your repair. We can be reached through private message if you have any questions.

Amber N.
Chevrolet Customer Care

 

I've owned 2 of these vans and had the same problem in both of them. No heat at idle, but as soon as the RPM comes up, you get heat. I drove until fully warmed up, turned off engine and waited about 10 minutes. Then very, very slowly removed the radiator cap while wearing leather gloves to avoid any danger. I found the coolant level was down slightly even though the overflow jug was filled to the hot line. So i then restart the engine (with the radiator cap off) and keep adding coolant until I cannot get anymore to go and replace the radiator cap. Problem fixed. I started getting hot air at idle. Fixed both of them this way.

 

Northbay555.I think You have a good point there. Like I was mentioning in a few treads above the anti freeze is not returning back completely in the rad while cooling down and thereafter creating air pockets in the lines.

 

Great forum!

Could you explain what you mean by "re-routing the heater core lines"? I am curious because like many others with this issue, I am wondering if it is something that was not installed correctly at the factory, etc. Did anyone attempt swapping the IN and OUT to the core?

I attempted to backflush my heater core this weekend with compressed air. I removed the quick connects near the firewall and attempted to blow compressed air back through the core as indicated in videos. Preparing for a load of Dexcool to splash me in the face, I placed the (in-side) hose in a jug. Upon blowing compressed air back, there was no flow. It was really difficult to get a good seal on the hoses though.

Thinking that there must OBVIOUSLY be a blockage, I tried from the In-side of the core, and air blew through the core and dexcool poured out the other side. (There was not as much as I would have thought though). I agree that this makes sense due to so many explaining that the heater core is mounted too high possibly?

My next step is to bleed the system with one of the recommendations in the post. (fill, let engine run, fill again).

It would be awesome if you could explain your fix, I searched for your other posts but not one explains how the issue was solved.

Thanks!

 

Be careful blowing air through the heater core, you can rupture the core with too much pressure.