AISIN THT-015 Engine Coolant Thermostat - Compatible with Select Lexus GS400, GS430, GX470, LS400, LS430, LX450, LX470, SC400, SC430 Toyota 4Runner, Land Cruiser, Sequoia, Tundra

My Water Pump started leaking on my 2005 Tundra 4.7 It was intermittent for a while, so I just kept the coolant topped up.It started getting worse, so I started ordering all the parts. Water pump, timing belt, ect.I hooked up my OBD scanner to see the actual temperature of the coolant, and it was hovering from 205 to 210, which is hotter than ideal for sure.After a long and exciting repair job, everything is back together, and 2 weeks later, the coolant temp stays at 186-187 consistently.I replaced the water pump, radiator, timing belt, tensioner and drive belt, also, but it's good to know the new Thermostat is working perfectly.I would venture to guess the old one was not Aisin/Toyota. I myself was tempted to get a cheaper one, as the parts list got bigger. But the old thermostat was definitely worn out. The rubber parts were all misshapen and definitely not sealing, or allowing flow like they should.Same with the radiator cap, the rubber was stretched out.So, while I replaced most of the entire cooling system, and the new thermostats effect difficult to say, it good to know it's working perfectly.The temperature would swing +/- 10 degrees when driving around before, now it maybe moves +/- 2.Side note, as many have said before, the dash temperature guage is not very helpful with these things. During the whole fiasco, it never read anything but right in the middle. If you hit 230 or 240 degrees, I'm sure it would let you know, but at that point things are getting bad. I use a $20 Bluetooth obd scanner I got here on Amazon, and it's been a great investment. Has helped me solve several issues.

Fits like OEM. Don’t forget to buy gasket! You must buy separately,,,, that part stinks.

I used FEL-PRO 35555 O-Ring and AISIN THT-015 Engine Coolant Thermostat for a 2001 Toyota Tundra V8.

I believe this AISIN model is made by TAMA (supposedly an approved Toyota OEM; private label noted on the box). Seems to be better designed/built than the Kuzhe (another Toyota/Lexus OEM) version.

Good price.....aways a BUUTTT. Why of all things......(you) don't sell a gasket.....useless with out it.Had to drive to an auto store to pickup a $3.99 part.

fits 1999 LC and works great

2004 Toyota 4runner / V8My thermostat went bad. Purchased Aisin and another no name brand. The Aisin has a much higher build quality than the no name brand. The only drawback is you will need to purchase an O-ring seperatly. This adds between $5-$10. Fit perfect and seems to be working fine.

Great product and brand new fit with no problem