1999 Grand Prix SE 3.1L

[robbo3]

Need to change thermostat, can anyone tell me where it is located and if it is an easy fix? thanks

[richtazz]

the thermostat is located where the upper hose meets the engine. The only difficult part can be bleeding the air out of the cooling system when you're done.

[StevePT]

You might as well change your coolant while you're at it. Also, if you don't drain it and you pull the water neck, you'll have a big mess on the exhaust shroud, tranny, etc.

To get at it best, you'll need to take off the throttle body. There will be two hose from the throttle body that connect to the black hardline for coolant that runs back to the heater core.

On the water neck, you'll need to take off the top bolt and the bottom bolt's hole is a semi-circle so you just need to loosen the bolt and then you can pull off the neck. Once the neck is off you'll see the thermostat.