Last week I replaced the thermostat in our 4.6L Mountaineer. I've ran the engine with the cap off to bleed the air out, but the engine is not getting up to normal temp. It's only getting to the first line on the temperature gauge. The old thermostat that I pulled out only allowed the engine to get to maybe 150 degrees. The old one was a 192F the new one is an OEM 180F. Far as I can tell this one isn't broken, but at this point I'm not sure what the issue is.

 

If the older stat was a 192 and it didn't let the motor get over 150 then going to a 180 stat will open sooner and start to cool sooner so it might not get warmer. Does the top rad hose get "burn your hand hot"? Is the heat hot or just warm? If both HOT HOT then maybe the temp sensor went south. Any corrosion on the harnesses?

 

... The first thing I met was a fly with a buzz
And the sky with no clouds
The heat was hot and the ground was dry
But the air was full of sound...

Is the thermostat OEM or aftermarket parts store service replacement? 192° F. is likely the correct temperature, and use a Motorcraft. Where is 180° F. listed as OEM? Plus, you live in Minnesota?? Install a 192°. Nod your head yes....

OEM won't guarantee a good part but the offshore stuff is always a crapshoot.

 

Upper radiator hose gets warm but not HOT. When I can let it sit for maybe 10 minutes it will go to the second line on the water temp gauge, but then with driving, it goes back down. At most I'm guessing it gets to about 120. I was only guessing with the old one, but for reference it went to 2 to 3 lines below it's normal running temp (one line below the half way). I'll take some pictures of the gauge if that can help when I can tomorrow morning.

Where is the sensor located you are referring to?

 

It's aftermarket Car Crash (Carquest). They said it was OEM Spec. I'm not in Minnesota anymore, thankfully. But Nebraska is still almost as bad. The options Advance Auto gave was a 170, OEM 180, 192 and 195.

 

it is screwed into the block

 

I would find out what the OEM temp is. Almost certainly 195°. Don't want to go less than that. Lots of complaints about aftermarket t-stats. Don't know why, but it's worth using OEM Motorcraft.

 

I replaced the cylinder head temperature sensor last summer as well as the wiring harness for it. Was having over heating issues last year, (turned out to be low coolant...long story) and thought that sensor was an issue. I'll be scanning the CEL that popped up and we can go from there, but this only just popped up yesterday.

 

Ford dealership the only place to get a Motorcraft t-stat besides online? I work next to a Ford dealer ship so I could walk over on my lunch break if need be, but may get laughed out at.

 

If I had one next door to me that would be where I'd go, EXCEPT they might charge too much, some crazy price. Maybe not. But what you need is a good part number and then search the intertubes. Motorcraft thermostats have solved weird problems often enough where it's worth seeking out the correct part. Same with ignition parts.

 

Can anyone verify if this is a genuine Motorcraft part number RT-1234. Supposedly its a 190F thermostat, it's a part number I get from Rock auto and google.

I have never understood why Ford engines are so freakin picky when it comes to parts. It's almost like they are built to malfunction with aftermarket or third party parts on purpose.

 

Are there any trusted 3rd party thermostats that should work 100% that I can get at a parts store? I'm starting to think if I can siphon out the thermostat housing, is there anything that can physically cause a thermostat to not work properly?

 

Starting to think that part of the problem is the intake manifold. Got to work today and the reservoir was really low and there was a lot of steam. Looked under the engine cover and saw fresh coolant. Grabbed the upper radiator hose and it wasn't firm like it should be. Anyone know how many hours it takes to do this? I cannot do it because I live in an apartment now, so I'm thinking of having the mechanics at my work do it.

 

I guess my dealership I work at calls for 3 hours and with my discount at $84, I'm at 252 for labor and then just need to see how much the part would cost here. So sounds like as soon as my refund is in, I'll be getting the intake manifold replaced.

So for a Motorcraft (from a Ford dealer) is $250 plus $25 For gaskets.

 

??? What is wrong with the intake manifold ? Are you saying the manifold gaskets leaked coolant onto the top of the motor ?