So, the ******* who owned my truck before me was a *******. From what I can tell, my thermostat housing is leaking because this idiot replaced the thermostat and left the old gasket, so i now have this wonderful leak that dumps a gallon a week.

Is this as simple as I think it is? Two bolts off, scrape it off, pop out the old thermostat, pop in the new one, new gasket, bolt it down, call it good. Right?

 

Pretty much. When I did mine, it seemed to help to get the paper gasket a little bit wet. Mine leaked a few times until I got it to stop.

The thermostat housing might be pitted-corroded, and could be leaking itself. The housing is available. Getting the pipes out of the old housing might be a challenge.

 

Changed my thermostat today in about 10 minutes, not counting the time waiting for some coolant to drain from the radiator. It's really very easy to remove and replace.

 

Yea doesn't take but a few minutes like previously stated, make sure you go with the original temp thermostat

 

Okay, stupid question time.
How do I drain the radiator without spraying coolant everywhere?
What is the original temperature for the thermostat? I'm seeing 160, 180, and 192, not to mention a few that are simply listed as "alternate temperature".
My truck is the 4.9L I6.

 

I'm pretty sure you need the 192

 

There is a petcock valve on the passenger side lower part of the radiator. Make sure the truck is cooled down, open the valve, and I also take off the radiator cap at that point to speed it up. I put a 190* in my truck. This one specifically -> More Information for MOTORCRAFT RT1139

 

Yeah clean off the housing with a wire brush install thermostat (stock temp 192) in the housing. put on a thin layer of rtv then put on the paper gasket then put another thin layer of rtv on the block and put it together. No leaks.

 

If you have a good gasket, you don't need RTV.

 

I got one of those cheapie weepie siphon hoses with the rubber bulb at the auto parts store and siphoned the coolant out the top of the radiator. no muss no fuss. Worked om my P/U and car.

 

I agree with you, but I've had a few leak with just the gasket and none leak since I started using the rtv/gasket combo.. RTV is cheap and I don't like doing jobs twice. Especially on water pumps.

 

Okay, I'm prepared to kill someone. I've been to 8 autoparts stores, spent several hours on the internet, and yelled at my dog (im not sure that was productive), and I can't find a name for this part.
When you look at the thermostat housing on a 4.9, there's another piece that screws into it, it has the coolant temperature sensor in it, and connects to the heater hose. What the hell is it called and where can I buy one?!?

 

Apparently its called an 'elbow' Found a couple part numbers. E5TZ-18599-A and
E5TZ-18599-C. Here's one for sale. ELBOW | Genuine Ford | E5TZ-18599-C

 

Great find!