F-150 thermostat?

[Buckmark]

I'd just change it.  Cheap part and an easy job.

 

Sure. Just change it. Spend your 2 hours and your money and when it's not fixed, throw some more parts at it that don't fix it.
The blend door actuator actually takes less time than the thermostat to change and the part is likely cheaper. Just FYI.

Nevermind. The t-stat pays 1.1 and the right side actuator that goes bad commonly pays 1.4 hours.
But...why diagnose anything when you can just throw parts at stuff.

Yeah but by the time you get coolant all over your garage/driveway, run to the parts store because you forgot to get the correct coolant, replace the stat, refill/burp the system and clean up the mess, you will be past the blend door time.....

[jackelope]

I'd just change it.  Cheap part and an easy job.

 

Sure. Just change it. Spend your 2 hours and your money and when it's not fixed, throw some more parts at it that don't fix it.
The blend door actuator actually takes less time than the thermostat to change and the part is likely cheaper. Just FYI.

Nevermind. The t-stat pays 1.1 and the right side actuator that goes bad commonly pays 1.4 hours.
But...why diagnose anything when you can just throw parts at stuff.

Yeah but by the time you get coolant all over your garage/driveway, run to the parts store because you forgot to get the correct coolant, replace the stat, refill/burp the system and clean up the mess, you will be past the blend door time.....

Didn't think about the correct coolant debauchery.

[Bofire]

and Beancounter is such a wizard with cars. what kinda oil???
Carl

[timberghost72]

An ECM controlled blend door issue if cold at idle and warm when idle is raised >1000? Probably not. Check the basics first. 

[jackelope]

An ECM controlled blend door issue if cold at idle and warm when idle is raised >1000? Probably not. Check the basics first. 

Is engine temperature ok?

[timberghost72]

An ECM controlled blend door issue if cold at idle and warm when idle is raised >1000? Probably not. Check the basics first. 

Is engine temperature ok?

  And check coolant level. Then what temp does the t-stat open at.

[coachcw]

Verify coolant level , turn and turn fan off for a couple minutes . rev engine to 1500 rpm and hold . turn fan on max and check for heat (good heat ) if heat blows hot for ten to twenty seconds then cools off look for a plugged heater core .

[CP]

I changed the T-stat on my 4.6L F150 not long ago.  Less than $15 and takes about 15 minutes.

Amazon Prime one day delivery on the parts, make sure it comes with the O ring.

Drain out about a gallon or so of coolant into a clean bucket.  The t-stat is at the top of the engine so you don’t need to drain much.
Remove the t stat housing (2 bolts, you can leave the hose on).  Toss the old t-stat and O ring, clean the surfaces, put in the new parts and reassemble.
Put the coolant that you drained out back in.

Done.

I have an Edge – programmer reader.  One of the supported parameters is engine coolant temperature.  Very useful to monitor the temp real time as you drive if you have such a question.  Well worth the investment if you keep your vehicle well beyond warranty and you do your own maintenance.

[Woodchuck]

On a '12 5.0 truck the thermostat in on the bottom. 

[CP]

On a '12 5.0 truck the thermostat in on the bottom. 

Well, that's unfortunate.   

[jackelope]

I guess I might check for fault codes before I did anything. T-stat and the actuators will set codes. We can all sit here and desk jockey this thing, but the OP hasn't answered any of the important questions to properly formulate an (in) accurate internet forum diagnosis.

I changed the T-stat on my 4.6L F150 not long ago.  Less than $15 and takes about 15 minutes.

Amazon Prime one day delivery on the parts, make sure it comes with the O ring.

Drain out about a gallon or so of coolant into a clean bucket.  The t-stat is at the top of the engine so you don’t need to drain much.
Remove the t stat housing (2 bolts, you can leave the hose on).  Toss the old t-stat and O ring, clean the surfaces, put in the new parts and reassemble.
Put the coolant that you drained out back in.

Done.

I have an Edge – programmer reader.  One of the supported parameters is engine coolant temperature.  Very useful to monitor the temp real time as you drive if you have such a question.  Well worth the investment if you keep your vehicle well beyond warranty and you do your own maintenance.

Solid instruction for a 4.6
He has a 5.0

[Angry Perch]

Got home last night and could smell coolant when I got out. Same this morning. Pouring rain, dark and no shop to work in doesn't make for a great combination for diagnosing a coolant leak. Heading over the mountains with the family Friday, so dropping it of at Evergreen Ford in the AM.

[Fl0und3rz]

Take it to @Coach shop, if he can fit you in and you can get it there.  I would tow (have towed) my vehicle there just to get it done right.

[jackelope]

Got home last night and could smell coolant when I got out. Same this morning. Pouring rain, dark and no shop to work in doesn't make for a great combination for diagnosing a coolant leak. Heading over the mountains with the family Friday, so dropping it of at Evergreen Ford in the AM.

Bring it to me. I'll take care of it for you. Evergreen sucks. PM if you want.
How many miles on it?

[Fl0und3rz]

That, too.