Heater

Let me ask a few things about the car and I will try to help;

The temperature gage on the dash of the car reads hot?
When is it doing this?
Turning the heater on makes the temperature3 gage read lower?
Is your heater blowing air that is not warm enough at times?
If so, when?

I will lok for your reply and get back to you ASAP.

Sometimes when i sit idle after driving, the guage would go to hot without the heater on. Then i drove my car down the road, i had my heater on and then it blew cool air instead of hot. Then when it blew cool air, i saw the guage go to hot, then after maybe a minute or so the heat began to go from cool to warm to hot, and then i saw the guage go back to the middle normal range.

There are a few things that could be going wrong. I would start eliminating things that are due for service anyway and on the cheaper end of the repair scale.
Start by replacing the thermostat and flush and fill the anti-freeze using a 50/50 mixture of anti-freeze to water.

The nezt thing I would look at if that does not solve the problem would be the temperature sensor.
Depending on the motor in your car, if it is a 4 cylinder I think it will be either a D-series or B-Series, the sensor for the temperature gauge is actually the temperature of the engine oil and there is a seperate sensor for the car Computer to take readings from to make adjustments.

If you have any further issue, let me know and we will go through that nexr step.