🔧 ACDelco GM Original Equipment 131-131 Engine Coolant Thermostat: Efficient Cooling Solution for Optimal Engine Performance Review

. I left immediately and now the trucks are warming up like they should. Increased fuel consumption as it works more efficiently.

Wrong PART! Ordered with 131-163 to replace both Duramax thermostats and received 2X 131-163. If you order it's the one closest to the firewall and has a few bypass holes, at least it should have them.

I bought both thermostats and both were made in Japan not China. I tested their performance in hot liquid and also compared them to the originals. Both opened about 5 degrees higher than the originals, but that makes their response times much quicker. They do get a little warm after installation as my testing has shown, but they work very well!

I've ordered several of these, some new through Prime, some used through Warehouse Deal. I received the new Prime products only in plain white boxes and the rest in plain white boxes in an ACDelco box. The plain white boxes say "Made in Japan" and an 8- and 10-digit part number. These white boxes are original from ACDelco and match what I received from the dealer. But be careful if you order a used bearing, I received fakes and wrong parts.

Replacement for my 2005 Duramax 2500HD. Fits perfectly with no problems. Make sure you get this type too if you have a Duramax diesel: ACDelco 131-163 GM Original Equipment Engine Coolant Thermostat I can confirm they have two thermostats. And since it's time consuming/tedious to replace one, you might as well replace both, even if you think it's just one. The factory service manual instructs the technician to replace both at the same time.

Worked great. Our GMC didn't heat (bad in winter, no heater). I checked the parameters and the rubber seal was partially missing. Doesn't look like it looked like that was the cause of the whole problem but I put them in anyway. Now heats up to the right temperature. They're not difficult to replace. Just get a container big enough to hold the coolant had to turn off the faucet and find another container to catch the rest.

For the LB7 (early 2000's) Duramax you will need two different thermostats that fit in the same housing. There is no traditional case gasket - thermostats have a rubber gasket around the perimeter that acts as a seal. I've had this truck for 13 years since it was new and it has never come anywhere close to normal operating temperature when the ambient temperature is below about 50 degrees Fahrenheit. I replaced those thermostats and now the truck is approaching summer engine temp pretty…

Identical replacement to the one that came from my 2002 Chevy 2500HD Duramax. My original thermostat was stuck open so it took over 30 minutes for the engine temp to rise above 165 degrees Fahrenheit which is way too cold for this engine to run. After swapping out with this one (and swapping out another thermostat too - this engine has two thermostats side by side under one housing, one opens at 182 and the other at 185 degrees), the engine was up to temp like it should, in 10 minutes or so So.