My 06 Sienna was running hot , the temperature gauge was moving erratically and my cooling fans were constantly on. After checking the coolant levels and fan clutch relay I decided to attempt to replace the thermostat myself. The job took about 2 hours and got messy since my thermostat was stuck closed, make sure you have a catch bucket for the coolant. The air box and battery must be removed to gain access to the thermostat housing. Three 10mm bolts were loosened and I swapped the old thermostat with the failsafe new product. Overall the job was very easy however I did loose a bolt and had to make another trip to Autozone for a replacement. Tip the thermostat has a air bleeder . Make sure that’s installed at the 11 o’clock position. Since the replacement of this part my Van has ran smoothly.
What kind of vehicle do you drive? 2006 Toyota Sienna