LOCATE THERMOSTAT ON 2002 ALERO AND HOW TO INSTALL

Honestly it sounds like your thermostat is either bad or was put in backwards,

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FOLLOW YOUR TOP HOSE AND IT WILL BE A THE ENGINE END.SHOULD BE JUST 2 BOLTS 2 REMOVE.GOOD LUCK!

Yes you can do it, provided you have the item, nuts are easy to loosen up and tighten.

FOLLOW THE UPPER RADIATOR HOSE TO THE ENGINE TO LOCATE THE THERMOSTAT HOUSING WHICH IS LOCATED AT THE END OF THE LOWER INTAKE MANIFOLD ON THE DRIVER SIDE.

Check Antifreeze/coolant level in reservoir. Check motor oil level.

Have cooling system checked. Drain, flush, fill with proper antifreeze. Change the thermostat as well.

Thermostat replacement on 3.4 liter, Not the thermostat housing is between the Throttle body and exhaust crossover. If you have small haves and the right tools you can remove the two botls without removing the crossover and throttle body. The bottom bolt to the thermostat does not have to come all the way out, there is a cut out on the housing so you can slid it out. Good luck and take your time.

1. Remove the air cleaner and duct assembly.
2. Drain the coolant until the coolant level is below the thermostat.
3. Remove the crossover exhaust pipe.
4. Remove the radiator hose from the thermostat housing.
5. Remove the thermostat housing bolts and clean any sealer from the bolt threads.
6. Remove the thermostat housing and gasket.
7. Remove the thermostat.
8. Install the thermostat.
9. Install the thermostat housing bolts and tighten them to 18 ft. lbs. (25 Nm).
10. Install the radiator hose to the thermostat housing.
11. Install the crossover exhaust pipe.
12. Install the air cleaner and duct assembly.
13. Good luck...
    
14. Fill the cooling system.
15. Install the thermostat housing and gasket.
16. Clean the mating surfaces.

You're going to lose some coolant, so have a bucket or other container, and some fresh coolant ready. Follow the upper radiator hose to the point where it's connected to the engine. The hose is clamped to a metal housing (water inlet) which is bolted to the engine. Remove the bolts (not the hose) and lift the housing to expose the thermostat (may require a little prying with a screwdriver or similar tool). Note how the old thermostat is fitted (which end is up), lift it out of the engine, and then remove all traces of gasket from the housing and the engine. Install the new thermostat and gasket, replace the bolts, add coolant as necessary, and you're done.

THERE A CROSS OVER EXHAUST PIPE TO THE FRONT EXHUAST MAG ON BACK OF THE ENGINE OVER THE TRANS RIGHT IN BACK OF THAT PIPE CENTER OF THE BACK OF THE ENGINE.

Its located on the lower radiator hose where it meets the block. Hope this helps you..