overheating but temp gauge says otherwise. 04 w/3800

[Allegretto]

I have a 2004 Grand Prix and it is displaying the symptoms of overheating but the temp gauge is not going above normal operating temp. I replaced the thermostat twice, and after driving for about 10-20 mins coolant comes out of the overflow. I'm at a loss, I'm thinking temp sensor(?) But I don't want to keep throwing unnecessary money into it. The fans work fine, the heater blows as it should. Any and all info greatly appreciated.

[Tech II]

Absolutely sure you have burped the system? Have you been losing coolant?

[rkvons]

Originally Posted by Allegretto

I have a 2004 Grand Prix and it is displaying the symptoms of overheating but the temp gauge is not going above normal operating temp. I replaced the thermostat twice, and after driving for about 10-20 mins coolant comes out of the overflow. I'm at a loss, I'm thinking temp sensor(?) But I don't want to keep throwing unnecessary money into it. The fans work fine, the heater blows as it should. Any and all info greatly appreciated.

So how does this coolant come out the overflow. You actually witnessed it, or was it wet when you checked under the hood. Also, is your upper radiator hose hot and your cooling fans running and blowing hot air off the radiator? A blown head gasket can cause coolant to come out the overflow without the engine being overheated. You should try to determine if you have a blown head gasket.

[Allegretto]

Yea I saw it coming out of the little hose that come out the back of the overflow. She shop said it was the high speed switch, so I'm thinking a relay perhaps? But I pray it's not a head gasket that's why I'm starting small and working my way up

[Allegretto]

Originally Posted by Tech II

Absolutely sure you have burped the system? Have you been losing coolant?

Yep saw it done at the shop they said there wasn't any air in the system (thankfully)

[aleekat]

Originally Posted by Allegretto

She shop said it was the high speed switch

Not really sure what switch they are referring to? Did they explain this?

[Tech II]

Doesn't make sense that the temp gauge is ok, but coming out of the overflow....had to read that again.....try a new radiator cap....

[Allegretto]

Originally Posted by aleekat

Not really sure what switch they are referring to? Did they explain this?

They didn't say. Just said it was the high heat switch

[Allegretto]

Originally Posted by Tech II

Doesn't make sense that the temp gauge is ok, but coming out of the overflow....had to read that again.....try a new radiator cap....

Ok I'll try that then get back with you guys