I am getting a little heat from my 2006 Grand Prix when I put the thermostat all the way to hot and the blower on the lowest setting but not very much. I can barely feel the difference between the temp being on hot and cold. I noticed the problem last winter but it seems to have gotten worse this year. Any advice?

Water pump may be bad,

The usual cause is a malfunctioning electric actuator on the air mix flapper valve in the HVAC box.

Ok fellow 2006 Grand Prix owners!! By trial and error, I went through the process of elimination because my car would over heat and had no heat inside. After changing the thermostat, I had to replace the water pump. However, after you do this, you need to open the inlet hose bleeder and let the air out a few times. This solved my issue of overheating and I now have great heat!!!

Sounds like the temperature blend door actuator may be bad or the vacuum hose to it is disconnected.

Poor Heater System Performance CAUTION
Check all fluid levels and adjust as needed, before operating vehicle for extended periods at idle.

1. Start the engine.
2. Idle the engine until the thermostat opens (upper radiator hose will be hot) Is the engine at normal operating temperature (approx. 200° F)? If yes, go to the next step. If no, go to step 16.
3. Set the mode selector to FLOOR mode.
4. Set the heater control selector to the warmest temperature setting.
5. Set the blower speed the lowest setting.
6. Carefully feel the inlet and outlet heater hoses at the heater core. Is the inlet heater hose significantly hotter than the outlet heater hose? If yes, go to step 14. If no, go to the next step.
7. Set the mode selector to PANEL mode.
8. Select the maximum blower speed.
9. Select the warmest temperature setting.
10. Place a thermometer into the center I/P PANEL air outlet and affix a second thermometer to the heater core outlet heater hose.
11. Record the temperature at the center I/P PANEL air outlet and at the heater core outlet heater hose. Are the two temperature readings about equal? If yes, go to the next step. If no, go to step 13.
12. Inspect and repair the cowl, cowl area, recirculation door, and the HVAC evaporator/heater core case for cold air leaks. Repair any problems found, go to step 17.
13. Inspect the temperature door operation. Repair any problems found, go to step 17.
14. Turn OFF the engine. Back-flush the heater core. Start the engine. Select the FLOOR mode and the lowest blower speed. Select the warmest temperature setting. Feel the temperature of the inlet and outlet heater hoses at the heater core. Is the inlet heater hose feel significantly hotter than the outlet heater hose? If yes, go to the next step. If no, go to step 17.
15. Replace the heater core. When the repair is completed, go to step 17.
16. Check for low engine temperature problems, Repair or replace as needed, go to step 17.
17. Operate the system in order to verify the repair. If the system operates properly, the repair is complete. If the heater still does not work properly, repeat the entire procedure.

change your thermostat... its probably stuck open not allowing it to get hot. its a fairly simple and inexpensive fix. Good Luck

check the thermostat its probally stuck shut so no air can pass through to the blowers

you have a bad/stuck/ wrong thermostat

you got two diff problems or more poss hvac control head, bad blower resister, bad thermostat, low on coolant, or plugged heater core

You might have a thermostat stuck open this will not allow the coolant to reach correct operating temperature.

Is the blower motor working? if not have you tried checking for a bad fuse. If the blower motor is working and you just aren't getting in warm air you may be low on coolant or maybe your thermostat is sticking. Trying checking these 1st if you haven't already. hope this has been some help.