GM Genuine Parts 15-11057 (12600172) Engine Coolant Thermostat Water Inlet Assembly

Works as it should. Fits properly. Would be nice if it included the hardware as I had to source those separately.

Purchased this for my 2004 Chevy Tahoe and it’s a direct fit. Comes with everything you need to make this job quick and easy. OEM standard quality for a fraction of local parts stores.

This is an updated Thermostat housing for older models requiring a water pump replacement. I used this on a 2003 Express with the 6.0L gas engine. People have knocked this for being made in Japan. It's a lot better than Chinese made junk. Works well and the Thermostat has a seal on it. Recommend using a sealant for the housing to water pump.

Running fine on a 2002 sierra 5.3 swap. I used ebay silicone hoses they run cooler and look better. Suprised this has not leaked, nice design on the fill neck and gasket. No rtv was used

This was a perfect solution for my GMC 2001 5.3L Yukon. It came complete with the thermostat which is not shown in the stock picture and a new upgraded gasket that fits perfectly on the housing. A nice upgrade in design from the original Water pump inlet and fits perfectly! I used this when replacing my water pump (ACDelco 251-743)along with an ACDelco 38158 Drive belt tensioner so every part of the water pump unit would be new. I also changed the fan and AC belts while I was at it seeing as everything was already taken apart and accessible. All parts where ACDelco and purchased right here on Amazon. I chose not to use any RTV silicon because everything was nice and snug and both parts worked hand in glove with each other and the engine block. I am very pleased both with the parts and the convenience of picking up everything in one place with quick delivery at a good price. There is also a lot of satisfaction from doing this yourself with the help of a few youtube videos!

Quality seems good, but it did not fit my son's 2003 Silverado with a 5.3L engine. His truck has the "integrated" thermostat/housing. Didn't realize this until after I purchased this new one and attempted to replace it while replacing the water pump. Had to pick up the correct thermostat at the local auto part store. Product page did say it fit this truck, and I'm sure in some cases it would. Just not in my case.

Perfect fit to my new Water pump. Operates very well.

Husband ordered to replace thermostat on his truck. Must have worked cause no complaints.