Motorcraft Thermostat Assembly - RT1254

Works Well, Ease Of Installation, Replacement Value

Fit a 2003 Ford F150 5.4L perfectly. Returned the heater and the temperature gauge to factory specs.

Some things you just don't skimp on ..your engine/ transmission depends on well regulated cooling system... this thermostat is OEM the old one didn't fail but almost 200.000 miles it was time!... preventive maintenance !

Seems to be thermostating. no o-ring. batteries not included

original equipment, fit was perfect, does not come with the internal gasket that is needed.

UPDATE:January 22, 2025Have been running the truck and it is operating as normal. No overheating, no temperature gauge issues. Appears this item is legit and works as intended.----------------Installed but haven't started truck yet to test out as we haven't put the radiator in. However, looks like a good part. This is the first time we've replaced the thermostat on our 2001 Ford F150 supercrew (4.6L v8) since we bought it (used). The old thermostat looks to be an off brand though I couldn't find any markings on it but I did notice the inner hole was larger than this one. Not an expert on the cooling system to know if that means anything or simply a design aspect. Anyways, truck has the factory tow package and came with 1 core (per the vin spec site) so I assume this thermostat should be fine. We are replacing the radiator with another single core so hopefully everything works out. I prefer to use motorcraft (or oem) in pertinent places that I don't want to have to keep replacing. I'm not against aftermarkets but in some areas, I just don't want to have to replace multiple times in short periods when the cheaper versions fail. I feel the cooling system is critical and should be using oem parts to get the best performance and longevity.

Fit my 2015 F250 6.2 , but keep in mind to get a gasket as it is not included

Works fantastic someone picky mouse wrong thermostat car didn't run right