Need Some Advice on Replacing Thermostat

[willied]

So I'm trying to replace my thermostat on my Explorer (which is the 4.6), but it seems almost impossible to get the thermostat housing off without either unbolting the alternator or something else. Does anyone know how to get the left bolt off? I've already got the right one off. Not sure how I'll be able to use a torque wrench to torque it to spec once I put the new one in without removing the intake manifold, but I feel like I can probably get away with just tightening it by feel.

 

[willied]

Anyone?

 

[stkelly]

I would just tighten it by feel. I replaced my thermostat when the intake manifold was off so I obviously had better access. However, when I tried to torque it down the torque wrench never popped so I just did it by feel. I've had no problem in 8,000 miles. Make sure to replace the thermostat gasket!! My old one was pretty beat up, luckily I had a brand new gasket ready with the new thermostat.

It looks like you could gain a little better access by taking off the throttle body. That's very easy to remove.

Also, that left bolt doesn't need to be removed all the way. The thermostat housing has a cut out so you can just loosen that bolt, lift and pull to the right and the housing will come up.

 

[willied]

I would just tighten it by feel. I replaced my thermostat when the intake manifold was off so I obviously had better access. However, when I tried to torque it down the torque wrench never popped so I just did it by feel. I've had no problem in 8,000 miles. Make sure to replace the thermostat gasket!! My old one was pretty beat up, luckily I had a brand new gasket ready with the new thermostat.

It looks like you could gain a little better access by taking off the throttle body. That's very easy to remove.

Also, that left bolt doesn't need to be removed all the way. The thermostat housing has a cut out so you can just loosen that bolt, lift an pull to the right and the house will come up.

Thanks! I ended up getting one of those ratcheting wrenches with a head that flexes and I think it should do the trick. I did take the throttle body off which certainly helps. And I got a new gasket as well so I should be set. Just have to get it done.

 

[willied]

Alright so it seems the intake manifold does need to be removed to get the thermostat out...great design. Anyway, is there anything special to taking the manifold off and putting it back on other than loosening and tightening bolts?

 

[stkelly]

Wow! Didn't realize it was a requirement to pull the whole manifold to get to that bolt. It really doesn't look like it when I go out and look. But again, I didn't try with the intake on.

You'll need a quick disconnect (I think it's a 1/2) for the fuel rail. It's pretty much impossible to get to the middle bolt on the intake manifold because the fuel line that goes over the middle of the intake is in the way. So you'll need to remove the fuel rail. Be sure to release the fuel pressure first!!! Run the car with the fuel pump fuse removed until the truck dies.

I assume you're just going to push the intake back instead of completely remove it to gain access to the bolt. If you're going to completely remove it, you'll also need to disconnect the intake manifold engine vacuum connector (if you have the coolant heated one). Also be careful with the vacuum lines that connect on the back of the intake manifold. I managed to break one.

It's actually not that hard to remove once you get everything else disconnected. There is a specific pattern when re-torquing the bolts on installation of the intake manifold. Here's what I used for bolt sequence:
http://www.americanmuscle.com/ford-racing-intake-manifold-install.html

Yes, it's for the Mustang but the 4.6 is the same in both vehicles. It gives you the torque sequence and torque.

Good luck!

 

[willied]

It's actually not the bolt that I can't get off now; it's the thermostat housing. It doesn't have enough clearance to be removed with the intake manifold in place, unfortunately. Hopefully I won't have too much of a problem getting it off tomorrow. Luckily I have a 1/2 inch disconnect that I bought for replacing the radiator (though I didn't successfully use it then; instead I just reused the trans line fittings).

Thanks again!

 

[stkelly]

It's actually not the bolt that I can't get off now; it's the thermostat housing. It doesn't have enough clearance to be removed with the intake manifold in place, unfortunately. Hopefully I won't have too much of a problem getting it off tomorrow. Luckily I have a 1/2 inch disconnect that I bought for replacing the radiator (though I didn't successfully use it then; instead I just reused the trans line fittings).

Thanks again!

Ah, that makes much more sense. It does look pretty tight in there.

 

[willied]

Alright, I got it all done today. I actually didn't have to disconnect the quick disconnect for the fuel rail. I just popped the fuel rails out and was able to get to the bolts on the inside. It wasn't that hard of a job, but it took a while (like 2.5 hours somehow). I took it for a 30 minute test drive and it the temp stayed constant (197) so I think it should be okay now. I was hoping it might also be the solution to my A/C sort of cycling between cold and only cool air, but it seemed to still be doing it so I imagine it needs some more refrigerant. I just don't want to pay a shop to do it even though apparently that's best way to do it (instead of using one of those little cans - but people do seem to like them).

 

[SixPonies]

What temp thermostat did you install for a replacement? I was thinking of installing a 180-degree one in my V8.

 

[willied]

What temp thermostat did you install for a replacement? I was thinking of installing a 180-degree one in my V8.

195. Why do you want to use a 180? I'd think that would reduce efficiency if the engine isn't running at the optimal temperature.

 

[stkelly]

I used the Motocraft RT1234 thermostat. I think it's 190 deg. The truck runs at 195 consistently.