07 Mountaineer V8 poor heat and temp gauge fluctuates a little??

[Mustang5.0]

Hi all! My Mounty has poor heat for some reason. It is warm, but not hot. It helps if I use the recirculate button, but not what it should be. I also noticed that the gauge fluctuates a little as well. it goes between 1/3 to 1/2 way sometimes. The coolant is full and I have replaced the radiator last year. I appreciate any help!!

 

[Explorer_PL]

I'll be watching this thread.
My 06 v8 heat isn't the greatest either and I can compare it directly to my son's 07 v6 and the heat just blasts.
No leaks, or anything in my case.
I do the same - recirculate and get by but something changed in the past 2 years.

Heater core ...?

 

[Mbrooks420]

Check both heater hoses. Both should be about the same, heat wise. Are you sure you don’t have trapped air? Does the heat get better when you are on the gas momentarily?

 

[Mustang5.0]

Check both heater hoses. Both should be about the same, heat wise. Are you sure you don’t have trapped air? Does the heat get better when you are on the gas momentarily?

RPM's don't seem to make any difference. I will have to check the hoses and compare them. The strange thing is the temp gauge moving. I always remember it staying at half way consistently??

 

[Mbrooks420]

Could be a stuck open thermostat not regulating temp.

 

[WaltZ]

I have to turn mine down because it gets too hot. When starting out, I have the front and rear heat and seat warmer going. Once the truck warms up, I turn off the rear. I keep the seat warmer going for the toasty butt feeling

Of course, this past summer I replaced ALL the hoses and t-stat, which probably helped

 

[07EddyB]

I'll be watching this thread.
My 06 v8 heat isn't the greatest either and I can compare it directly to my son's 07 v6 and the heat just blasts.
No leaks, or anything in my case.
I do the same - recirculate and get by but something changed in the past 2 years.

Heater core ...?

PL - I posted not long ago about replacing my heater valve due to a leak. Since doing that, and topping off the radiator for the umpteenth time, my Ex has better heat than it has had in a long, long time. I think I mentioned in that thread that you should look at the bottom of it with a mirror. It should have a nice, neat appearance with only the ring around the actuator visible - it should actually stick out some. If you see any other rubber sticking out, or you can't see the rubber ring around the actuator, then the bellows had been trapped and it's not all the way open. If that is the case, then remove the vacuum line and work it up and down a few times until everything is seating. Anyone with poor heat should check this out.