Thermostat?

My venture doesn't blow heat into the cab even when the temp gauge is around 90 degrees. When I let it idle, the temp gauge rises really high, but when I start driving again, it goes back to normal temps. Is this a thermostat problem?

What is really high? Don't let it go into the red. I wouldn't expect much heat at 90 but you should get heat when the needle goes into the normal operating range mark. At idle it's normal for the guage to go up to maybe 2/3rds until the electric fan kicks in. You won't notice that when the car is in motion or with the a/c on even at idle as the electric fans are in operation when the a/c is turned on

Sorry I meant the temp. gets to normal operating temp. and had been running for 15-20 min and it's still cool in the car. My Olds Intrigue is warm within that time period and are most cars I think. When it's idling after the engine has warmed up, the temp gauge gets pretty close to the red and then the cooling fan starts to kick in, but stays close to the red. Then I start driving and the temp gauge goes down right away.

Might be the thermostat then. It's certainly the cheapest point to start looking, but if it's in the operating range and your not getting heat might also be a clogged heater core

Ok thanks for replying to my post, I appreciate it. Do you think it could be because my coolant is low? It is a little low, but I can still see the fluid in the reservoir. I will top it up tomorrow, before I go anywhere and see if that helps.

If you are getting low on coolant, check your oil for coolant (might show higher on stick also). If so check lower intake manifold gaskets and possibly head gasket.....