I havea 2004 buick rainier that the driver side rear tire will lock up. Any ideas?

The thermostat on a 2004 Buick Rainier is located under the housing that connects the large radiator hose to the engine block. You will need to remove the cap that is held on with 2 or 3 bolts to access itI think this is on the passenger side but some diagrams have it on the other side.

Due the constant bending of the wire harness buddle to the rear hatch when it opened and closed in many cases the wires fail from metal fatigue. What you need to do to get the rear open is remove the trim panel from the inside and manually trip the latch and then perform wiring diagnostics to the various powered components of the rear hatch to locate the broken wire(s).

If dog ate the old ones, trim away old remaining material and gently pry the panel away from the door's edge. You should be able to see the shaft of the plastic retention clips which are just push-fit into door.

Might find a new garage if they couldn't tell you what it was exactly. AC pump is directly behind the tire, could be that??

May have screw in handle area..but then pry carefully around to release tabs

GM TSB#PIP4045A
NHTSA ID#10024345
Summary: EATON LOCKING DIFFERENTIAL CHATTER SHUDDER NOISE ON TURNS, EQUIPPED WITH A LOCKING REAR DIFFERENTIAL RPO G80. *NJ UPDATED 7/17/2008. *PE
hope this helps

I have no idea of the location, but I seriously doubt it is on the bottom left side. T-Stats are usually on the top side. Follow the top radiator hose back to the engine and it should be under neath where it attaches to the engine.

Could be one of several problems in the rear diff.
It depends if its the optional locking rear diff and it's stuck locked, or it is the limited slip and something inside caused it to lock.

See a mechanic before you do more damage.

try repositioning the nozzle to get it aimed higher, and use a small wire to see if there is somthing plugging it that can be dislodged.

These are side products of the all wheel drive system, incombo with the locking rear dfferentials.

You'll find the auto-lockers will tend to do that following a tight turn, particularly when you're doing it quickly.

The thud is similar in nature; it's just the All wheel system trying to figure out where to put the power.