How to Change the Thermostat in a 2002 Grand Prixby Lisa Wampler
The 2002 Pontiac Grand Prix is considered to be a sport sedan that is not only capable of taking the kids to football practice but can get them there fast. High-performance vehicles like the Grand Prix can be prone to engine failure if attention is not paid to the systems that keep the engine performing properly. The oil needs to be changed regularly and the coolant system should be inspected. If you've noticed the engine running hotter than usual, inspect the thermostat sooner rather then later.
Remove the radiator filler cap on the Grand Prix and set it off to the side. The engine should be cool to prevent the cooling system from spraying vapor out of the radiator filler.
Remove the radiator hose from the thermostat intake housing by removing the band clamp that holds the hose to the housing. This is done with a nut driver or a screwdriver. Slide the band clamp further onto the radiator hose to prevent losing it and pull the hose off of the housing. Push the radiator hose off of the side. It's possible that fluid will leak out of the hose. To prevent this, keep the open end of the hose facing upward.
Remove the two bolts that hold the thermostat intake housing onto the Grand Prix's intake manifold with an 8-mm wrench or socket. The bolts should be retained as they will be used again when installing the new thermostat.
Pull the old thermostat out of the intake manifold and discard it. Pull the old thermostat housing gasket off of the intake manifold and discard it. Nether item will be used again.
Place the new thermostat into the intake manifold. The thermostat must be put into the engine with the correct end up. The thermostat will be stamped "top" on one end. This is the end that should stick out of the engine.
Place a small bead of PVC gasket maker on the machined mating surface of the intake manifold. Allow the PVC to "skin over" or cure for 15 minutes. Place the gasket on top of the PVC gasket maker. Place a small bead of PVC gasket maker on the bottom lip of the thermostat intake housing and allow it to cure for 15 minutes. Place the thermostat intake housing onto the intake manifold and tighten it down with the original housing bolts. A small amount of gasket maker will squeeze out of the seam. This is normal and will aid in the sealing process.
Reconnect the radiator hose by sliding it onto the thermostat intake housing and tightening down the band clamp. Place the radiator filler cap back onto the radiator.