Hurley91

So my F150 started running colder than normal this month. It used to sit at the middle of the temp gauge, but now it is below a quarter. I thought it might be the t-stat, but wouldn't it run really hot or really cold if it was that? Any suggestions?

Thanks alot guys

Truck Specs:

-2000 F150
-5.4L
-185,000km (110,000 mile)

ProZach

if you're getting excessively cold temps then your truck won't be able to warm up all the way. have you turned on the heater during this? if the heater isn't getting warm then it's just too cold outside and you should get on of those covers for your grill to put on during the winter to prevent airflow into the engine bay, then it will warm up

givecjadollar

i've seen those covers on several different types of vehicles. what is the logic in preventing the airflow?

Hurley91

Even on warm days ( +0*c ) it still runs cool. I have turned on the heater, it bolws lukeware air, it does eventually warm the cab up... but it takes a long time.

ProZach

air is too cold and keeps engine from warming up, less airflow or no airflow to the engine bay= warm engine

if its continually blowing only lukewarm air then your engine isn't being allowed to operate within its normal range, there shouldn't be any damage but your engine won't perform as well as if you had something blocking the grill.
hell even a piece of cardboard taped in front of the radiator works

craigt502

Even on the coldest days, below 0*F, every gas vehicle I have driven eventually got to operating coolant temp (which is usually middle of the gauge or between 180-200*F)


Perhaps your radiator fan clutch is engaged all the time?

If your thermostat was stuck open, the coolant temp would take a longer time to heat up, and then keep the temp cooler as you drove. Does it take a long time for the coolant temp to rise?

The grille covers, are preventing excess air from passing through the radiator, which would normally cool the coolant.

Good old Bill

"I thought it might be the t-stat, but wouldn't it run really hot or really cold if it was that? Any suggestions?"

T-stats can fail sticking closed, open, or in between. Sounds to me like yours is the tweener.

In your case with gauge not reading as before and the heater operation is verifying, its time to go after a new t-stat.

jayson_waltz

Sounds to me like it is a t-stat problem if its only blowing lukewarm air. I've had them before where it take forever to warm up (even on highway trips) and sometimes would never even reach the normal mark. They are only like 12 bucks, throw one in and see if is helps.

Mr. Cracker1974

Definitely your t-stat. Mine was doing same thing. Trust me. 10 bucks and your done

bob101770

Is your clutch fan working or is it locked up? Had the same problem a few weeks ago and it was the clutch. I could move it by hand but as soon I started it up the fan clutch would lock up in about 10-20 seconds even though it was cold as hell. Temp would'nt go above a 1/4. $55 for the clutch at Advance Auto and it's back to normal.