Where is the thermostat located in a 2004 Toyota Sienna?

Answer 1

I just changed out the timing belt, water pump, thermostat, (all from Autozone) and upper/lower radiator hoses on my 2004 Sienna V6 3.3 @ 82,000 miles. My wife and and I ordered this van new in 2003 when this model came out. We live in hot AZ so I knew our Sienna was due. The thermostat is located on the drivers side near the top back part of the engine. Follow the lower radiator hose up to the engine. The hose then conects to a plastic pipe that runs under the top part of the engine. This plastic pipe bends and connects to the engine block with 3 nuts. There is also 1 bolt that needs to be removed where the lower radiator hose connects to this pipe (bracket). I had to remove the battery, air filter housing and disconnect a few wires to get to this pipe. When you disconnect this plastic pipe from the engine where the 3 nuts are, you will see the thermostat sticking out a little. I purchased a new thermostat @ Autozone that did not come with a gasket. When you pull out the factory thermostat, there is a rubber gasket that I took off and put on the new thermostat to seal the connection. THE AUTOZONE THERMOSTAT LOOKS (cheap) DIFFERENT COMPARED THE FACTORY THERMOSTAT. I put it in anyway and the car runs great. If I had to do it all over, I definatly would have purchased a thermostat from the dealer, it just looks like a much higher quality thermostat. I had to order the radiator hoses from the dealer as they were not available anywhere. 1 of the cam gears slipped 1/4 turn as I put on the new belt. I realy freaked out but there was no damage. I talked to a Toyota certified mechanic and he said this was a non interfearance motor. It still runs great.