How do you replace the water pump and temperature valve on a 1998 Pontiac Grand Am?

unfortunately, i believe this requires removing the timing chain because it drives the water pump. this can be a costly process ranging from 400 to 700 dollars.

Changing the water pump is a piece of cake. I don't know about the temperature valve though. To change the pump (on the 3.1)

1.Disconnect the water hose from the pump, catch the coolant below with a wide drip pan.

2.Using a serpentine belt removal tool (long thin rod with a 3/8 inch socket) loosen the belt tensioner and remove the belt from the alternator

3.Remove the 4 bolts from the water pump pulley. You will have to use a long screw driver to hold the pulley in place while you turn the bolts. Put the screw driver between 2 other bolts to keep it from turning.

4.Pop the pulley off. You may have to pry it off with that same screw driver if it's stuck on there. Be sure not to bend the pulley though.

5.Remove 5 bolts holding the pump in place, scrape off the old gasket, put on the new gasket with some sort of gasket dressing or sealant and pop in the new water pump. It only goes in one way or the holes won't line up.

If you happen to have a 96 ;or 98 gt model, which was the 2.4l twin cam, 5 speed manual. You have to pull the motor out. I don't know about timing chain being in the way or anything, but basically if you've ever changed an alternator or major part before, once you get the engine out of the car, it is one of the easiest jobs to do, just don't bend your pulley, and if you have underdrive pulleys (bigger than stock) you might want to make sure your using a brand new water pump, and not a used one. The temp guage, screws out, just put a new one in. Use TORQUE WRENCH.