Got a code P0128 saying that the truck was running to cold or under temperature and figured it was a messed up thermostat. Changed out the thermostat with the gasket and it ran fine that day. By the time the next day came around all the coolant leaked out from the thermostat, and I’m guessing the gasket messed up. I opened it back up and re did it 3 times and it’s still leaking, my question is is there a torque spec on the thermostat because I’ve tightened it until it can’t tighten it anymore and it still leaked for the second day in a row

 

I have not had the thermostat out of a newer truck, but the older ones had an o-ring seal, not a gasket...... If you have the bolts tight and everything leaks out, I would say the seal / method is a problem, not the torque.

what motor / year truck ?

 

and are you SURE its coming from the thermostat housing....... or maybe the TUBES in the valley of the motor below the thermostat ?

 

2013 Ford F-150 5.0 but I meant an O ring seal not a gasket my mistake. It’s leaking from the housing so I’m guessing the seal isn’t sealing right. I just didn’t know if there was a torque spec on the housing or not and was wondering if I was tightening it too much. I saw it leaking from the housing though and no other tubes were leaking.Tomorrow I’m gonna buy another O ring and try it again.

 

Did you use the OEM thermostat and seal? If not it will leak, rather common side by side the gates and felpro seals are not the correct dimensions.

 

yeah I bought a Motocraft thermostat but it didn’t come with its own O ring seal so I bought the fel pro O ring. I guess that’s the problem

 

Yes that's your problem huge difference side by side. You need Motorcraft W0133-1884388. The Motorcraft thermostats are not sold with seals.

 

motorcraft thermostat and O ring worked like a charm! Thanks for the help