Weak heater

[OldBlue67]

After a good cold snap over here Im remembering something: my heater just does not heat the truck. Everything turns on fine, but the airflow seems rather weak. The air also isnt as warm as I've noticed on other trucks. What would be causing this? The fan going out?

[fordman]

maybe clogged ducts or poor intake. motor speed dirty heater core

[kknip]

Might want to disconnect the heater lines and flush out the heater core,also as fordman said the face of the heater core could be clogged with debris such as pine needles or leaves.As easy as it is to remove the heater box,might as well take it out and clean/replace the heater core and check op of the fan.

[FORDification]

As for the lack of temperature (as opposed to air volume) you might find in colder temperatures you'll have to insert a piece of cardboard in front of the radiator, to allow the temps to get higher. In a pickup I once had, in order to get any heat inside at all I had to completely cover the front of the radiator in the wintertime.

Of course, a higher-rated thermostat will help as well.

[67F250CS]

Also check into your thermostat. My PO removed it for whatever reason. Came from California so probably never needed much heat. I found out when I moved North Carolina. The top radiator hose never really got that hot after runnning for quite awhile so I pull the housing ad found no thermostat was in the engine.
One other thing is the resistor block in the back of the heater box. One of the element might be going south. Does the fan work on all speeds?

[heep70]

If you take you core out make sure you can see through the fins. The cores like to swell and won't let air pass.

[jor]

you might find in colder temperatures you'll have to insert a piece of cardboard in front of the radiator

I used this technique when I lived in the cold climates. One word of caution though - When you do it, cover only 1/3 to 1/2 of your radiator surface and keep an eye on your temp gauge. If it gets too hot, just cut the cardboard down until you get a normal temp reading. In addition, I'd make sure I had a 195 degree thermostat in there for those cold Silverdale mornings! I mentioned before that I lived in Silverdale many years ago. We passed through a few months back and I gotta say there was nothing I recognized!
jor

[QC]

Make sure you clean all the snow off the air intake at the base off the windshield.

[averagef250]

Ahhh, the corn flakes thermostat! My buddies Isuzu 'pup diesel shop truck sports one currently. He has a good system down right now. The cornflakes box is just about discintegrated or fell out by the time he's eaten another box of cereal.

[19674x4]

Ahhh, the corn flakes thermostat! My buddies Isuzu 'pup diesel shop truck sports one currently. He has a good system down right now. The cornflakes box is just about discintegrated or fell out by the time he's eaten another box of cereal.

i have no idea, what you said, but it's funny.




i agree with the cardboard idea to, ive done it

[bugser]

Snow from the intake???

All I get is those durn doug fir needles. Still,it keeps the interior smelling country fresh.

[flyboy2610]

If you have the stock fan on there, get rid of it and put on a thermostatic fan clutch. Then the fan won't be trying to constantly cool down the engine. I did that to my truck and it was a HUGE improvement.

[ICEMAN6166]

Snow from the intake???

All I get is those durn doug fir needles. Still,it keeps the interior smelling country fresh.

sure it does, if your cowl and vent and heater air intake are filled with them.
seen em packed with leaves, sand, needles. eventually they will fall out the big hole they create if not cleaned.
a little bit of snow coming in thru there shows the system is free of obstruction and the fan blows good.liquids should go out the drainholes at the bottom on either side.
it gets cold here in the winter.
using a good heater core with clear flow of air/coolant and 195 stat.
you really should need no cardboard.even at -20F.if you have a lower temp stat, blocking the radiator will just keep it open rather than letting it close which creates heat because the coolant is flowing thru the head into the core and not into the radiator when its closed.195 makes a lot more heat than 175,the difference between above freezing and being toasty in your cab.
often overlooked: its not the heat but the cold.might have good heat but leaks of cold air coming in thru other places may negate the effect.

[OldBlue67]

Thanks everybody! I kinda posted this and forgot about it Blue is parked on a hill away from trees, so the pine needles (which are a huge pain in the butt most of the time) arent a problem for me. I'll double check to make sure I havent got some old ones crammed down there causing blockage. The heater core is only about two years old so it shouldnt be too bad (doent mean it isnt), I'll check it out just to be sure. I'm not sure what kind of thermostat I've got in my truck, but its worth looking into.

I dont know if its cold enough to block of the air flow, my definition of "cold" is a lot different from you guys who live where it...like...snows The fan is working at both speeds, so It probably isnt the fan like I'd originally wondered.

often overlooked: its not the heat but the cold.might have good heat but leaks of cold air coming in thru other places may negate the effect.

This was actually my next thought. I know I've got cold air leaking in, but I'm having trouble tracking it because I can only tell where its coming from when I'm driving and its not the best idea to be rooting around the floor/under the dash at that point But I think thats another thread.

I'll get under my hood/ tear apart my heater and see what I come up with thanks guys!

[19FORD67]

i have a duct that has come loose, hope it's this simple.