I noticed that when sitting idle at stop lights, the van was not blowing any heat out of the vents, but that when moving, or revving up the RPMs while in park, I would get heat blowing. The blower never stopped, it was just that no heat was being generated.

My brother-in-law is a mechanic. When I talked with him, he said there was probably a blockage in the rad, that I would need to get a high-pressure rad flush.

I went to my local garage, they did a rad flush including sending something like TSP or CLR through the Radiator to get rid of all of the junk. After this, the van is now blowing heat the way it used to. I live in Canada, it gets cold up here so I really needed this, especially when stuck in stop and go traffic.

Luckily it was a cheap solution.

The 2009 Uplander can be left to idle after a cold start indefinately and will not warm the cabin of the van. The engine temperature is at normal operating temp by this time. This usually only takes 15 minutes or so. Increasing the RPM to 1500 results firstly in a smell which I can't recognize; it is not coolant; followed by warm to hot air. Letting the RPM drop to normal idle results in much cooler air being blown into the cabin. After 2 or 3 minutes, increasing the RPM results in the short period of smell and back to much warmer air. Traveling at highway speed the heater seems to work properly. Around town it is a real pain and to me is NOT NORMAL. If it is, GM should not have been allowed to sell Uplanders north of Florida and California.

This winter 2012-13 is the first winter I have noticed this problem. Our local GM dealer says it is operating normally. Horse Hockey!! IT IS NOT NORMAL!!!! Anyone with this problem, please post; I feel so alone at the moment. If you know how to fixed my problem, besides selling the problem to someone else, please post.