Thermostat OEM Audi or AISIN

It's a very easy thermostat to replace, I just did it a couple days ago on a 2008 Hyundai Sante Fe with the big 3.3l V6. The gasket comes with the OE Aisin thermostat, too, making it even easier.

Not the water pump but I just had my thermostat replaced under the extended warranty. I was slowly losing coolant with no discernable leak.

I just got this done and Audi quoted me $2500 for just the thermostat. Mine was covered by the extended warranty Audi has on all water pumps leaks.

the 80c has been running flawless. Only difference is that my coolant stays at 83-94c. It used to get as high as 100 sometimes. Also the 80c part was recommended oe part #

Been running the 80 for a month or so. It works great. Car and Temps run flawlessly. Only difference is my average warmed up Temps are 85c. Used to be 95c

The OEM Aisin thermostat opens at 185, staying completely closed until 180 where it can open up partially allowing proper circulation and proper temperature control. The engineers at Nissan designed this cooling system to function in a certain way at very specific temps. ONLY USE THE AISIN 185 OEM thermostat in these trucks.

I finally got around to installing a new thermostat/o-ring/housing and coolant reservoir/cap yesterday. When removing the thermostat, I noticed that the bottom bolt was VERY loose... I had done the thermostat without housing about a year ago now, had never leaked coolant before... My best guess is that I just didn't torque it enough and it slowly loosened, but only when cold (just a guess, but would help explain why no drips when car was running on ramps) and in small enough amounts that I did not notice a puddle on the ground.

New thermostat (Aisin brand), fresh oil, fresh coolant, replaced at that time. Coolant system bled well. No leaks. Heat worked flawlessly. AC worked after the swap. Overheated the drive home after that swap, turns out the radiator fan module got fried on the final drive (it was above 250 on coolant temps before replacing the engine, on a 30 minute, fast, highway drive). Ordered a new one. Everything working perfect now at the right temperature points. Engine times reading perfect too (watching live data). On a 30 minute highway drive tonight, returning home after the same drive 2 days ago with zero issues, it overheats again. Radiator fans are working. The one thing I changed during the drive was turning down the heat from HIGH to 75. No more than 10 minutes later I hear the bubbling in the heater core area. Take my exit from the highway, and the red temp light starts flashing, temps read 239, and the bubbling worsened. Temps stayed above 228 until I made it home from my exit. Worse at red lights. Turned off for 10 minutes, turned back on, temps went up to 232 at idle, holding steady. Lower radiator hose read 102 degrees, upper hose reads 190.

My Q5 with 75,000 miles on it developed a leak in the water pump area. Initially Audi denied there was a leak, so I took pictures and showed it to them. Then they diagnosed it with thermostat leak.

The current plastic thermostat looks a little more beefy, but is still shatty plastic. They're commonly failing at 30-55k miles in the stuck closed position, instant overheat.