How do i change my Thermostat on 2001 Impala 3.4L?

Answer 1

It is relatively simple if you have a general tool kit and some patience. I just replaced mine yesterday and it wasn't too bad (aside from the trip I had to make to get some deep well sockets (metric) and a couple 3/8 drive extensions...).

First (I didn't do this) try to drain some coolant from the system; either try to locate a drain valve on the radiator (I don't know if there is one) or make sure you're on a surface you can easily clean when you start this project. If you cannot drain any coolant from the system go ahead and locate the coolant tube running from the top right hand side of the radiator (if you're standing in front of the car) to the "goose neck" attached to the block (it's right in front of the throttle body).

Next: clamp and slide down the clip holding the tube on the goose neck (not the radiator) and bend the tube to one side and out of the way (if you could not drain some coolant from the system it will spill all over at this point).

Next: locate and remove the breather tubing from the air filter housing to the throttle body. You do this by loosening two hose clamps with a standard screw driver: one attached to the air filter housing and the other to the throttle body. Remove it and set it to the side. (Note: there are some electrical connections and other tubing attached to these, you can disconnect them and remove them, just make sure you put them back. You'll need the room to work though, so go ahead and do it).

Next: you'll have to remove the throttle body to make room to work on removing the "goose neck". before doing that you'll have to remove the throttle cable bracket being held on by three or so 10mm nuts. The body is attached by three 13mm bolts/nuts (and one 10mm nut that holds on the throttle cable bracket on the bottom right if you're looking at the body from the right side of the vehicle). (Note: You may want to check to see if you need any gaskets for the throttle body, I did not replace any gaskets except for the one that came with the thermostat).

Next: There is a line running from the water pump (on the left side of the compartment) and it wraps around under and in front of the goose neck, it has three hoses attached to it, two that run under the goose neck and one on the end of this line, you'll want to undo those hoses and loosen the one bolt on the line attached to the water pump, only enough to move the line out of the way (do not bend this line!!!!). (Note: another gasket on the water pump/line you might want to replace. I did not and haven't had any problems.)

Next: once that line is semi-out-of-the-way you'll have to try removing the heat shield on top of the exhaust manifold running under the goosneck. I could not remove it but could only sort of move it out of the way just enough to loosen the bolts on the goose neck. This shield has four small bolts, they are on very tight because of all the heat and they may break off easily if you're not careful. The best way to go about doing this is to break it loose and turn it until it gets hard to turn again, then tighten it back up and then loosen again. Repeat this until the bolt is out. If you don't do this the rust in the threads might seize the bolt and cause it to twist apart, leaving the head off and threads inside.

Next: remove the two 10mm bolts from the goose neck and remove it from the block (easier said than done). Heads up... it's not easy and takes a little time and scratched hands to get them out. Best way is to use the open end of a 10mm box wrench. A ratchet will not work, sorry (doesn't mean you can't try thought!, good luck).

Next: Once the goose neck is off you can pull out the old thermostat with some pliers and clean the old gasket from the goose neck and block. Make sure you have a gasket for the thermostat (mine came with the part), install the new thermostat and re-assemble the many parts you have scattered across the floor, hood, engine compartment, tool box, etc. Good luck, and please remember to double check all parts you've removed to make sure you have everything back where they came from. If you have extra parts lying around it's a good indication you forgot something. Happy Mechanicing!!!