So ever since I could remember all my 3800 series motors blew cold air and never really got hot. Hell my current Grand Prix is hotter when I have the air off. What part would be causing this?
I'm going to start with the thermostat and actuator, hopefully it works. changing the heater core is time consuming and rather sell if it's that. Thanks for the responses
If your engine temperature gauge works and it's running at normal temps, it's most likely the heater core.
Why not spend a few extra and get a new part with a warranty? I don't advise ever getting a heater core from a junk yard. I've seen it more times than one where people do this and they bring it back a month later with another leaky ass heater core and have to spend another few hundred to get it done right when they could have do it right the first time. Best thing to do imo just take it and get it diagnosed.
Quite a few things..... That is a common problem. People put junk on the dashboard, and it makes its way down the defrost vent to the blend door, and either jams or breaks it. Go through all the controls to make sure you hear everything moving the way it should. If you're twisting knobs, but nothing is happening, that may be your culprit. If it was the thermostat stuck open, the car would run cold for a while, but once it comes up to temp, the heat would work fine. If its stuck closed, the car would overheat. I wouldnt bother with that. ^^^This is another common problem for a little to no heat problem... Especially in a "closed system" like yours is. On the thermostat housing there should be a small bleed screw. Start the cold car and crack that screw. There should be no air in the system. Those 3800's are NOTORIOUS for being a GIANT PITA to get all the air out of the system..... I wouldnt bother with the heater core, unless you have reason to suspect its clogged. (Like everything else is clogged/There is a lot of sludge in the cooling system) The way to check is to start the cold car and turn the heat to full hot. Hold the heater core lines (Or use a digital laser thermometer) located on the firewall. If one side gets hot, but not the other, you'll know its clogged. Hope this helps
Don't remember what series it is but some of them have 2 bleeders on them. And don't tighten it to much, they're made of brass and will break.
If it's the heater core it could just use a good flush. Bring the car up to temp and check the lines at the heater core as they go into/out of the firewall. One should be VERY HOT and the return to the engine should be HOT. This tells you that fluid is making it through the core if not them the heater core is clogged. A flush kit and a couple of gallons of coolant should fit the problem. If everything is HOT them check the blend door issue. Some cars are known for this I don't know if GP's have this problem though. One thing to check and I don't know if Grand Prix's have one but some cars do have an inline valve on the heater line. It prevents the flow of fluid through the heater system. My Lexus SC300 did. Just something to check Don't waste time or money on thermostat it's not the issue.
Took the glove box off, it seems I have to manually turn the actuator to heat, and turn the air on to keep it in place and blowing hot. Once the air shuts off you can hear the actuator turn and go back to cold. Thanks for the tips all!