I am having some intermediate heating issues with my 03 SE. I have narrowed it down to the heater core, bad smell of coolant in the cab, foggy windows, lack of heat. I just replaced the thermostat today, and I know that is not it. I have replaced one before in other GM cars, but not in a Bonnie. I have a manual and it gives half *** instruction. I am looking for some guidance, or some pics that show me how to get this done. I have this car for sale is anyone is looking. Here is a link to my craigslist ad.

2003 Pontiac Bonneville SE

Thanks

You may have a leaking EVAP core. This write up explains how to clean the core. But you can use it to open it up and inspect it as well. Let us know if it helps. If not, let us know and we will do what we can.

https://www.gmforum.com/t278997/

Thanks Dan! I actually ended up doing a coolant flush and it cleared up the problem. I might have the same issue on my 02 SLE now, so this will be helpful.