No Heat.
Thread Starter
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Laughing Gas
Joined: Dec 2010
Posts: 924
Likes: 1
No Heat.
Hi guys.
I'm getting lukewarm heat when I'm driving almost cold air. When I park the truck it seems to begin to warm up again. I just replaced the heater core yesterday night both heater hoses are hot to the touch. I let it run for quite a while and it warmed up good actually I know these trucks have awesome heaters because my 86 f150 has no happy medium its either you have the heater on or you don't. Haha.
The only thing I could think of is that the thermostat is tired although it this didn't happen before the heater core replacement (old heater core was leaking).
I'm getting lukewarm heat when I'm driving almost cold air. When I park the truck it seems to begin to warm up again. I just replaced the heater core yesterday night both heater hoses are hot to the touch. I let it run for quite a while and it warmed up good actually I know these trucks have awesome heaters because my 86 f150 has no happy medium its either you have the heater on or you don't. Haha.
The only thing I could think of is that the thermostat is tired although it this didn't happen before the heater core replacement (old heater core was leaking).
Thread Starter
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Laughing Gas
Joined: Dec 2010
Posts: 924
Likes: 1
Okay. Maybe I overreacted. I could hold on to the hose maybe not for long but I mean you could touch them and then say okay the heater should be warming up now. I wouldn't think it would be a blend door problem because the cable to the lever was broken when I got the truck and is stuck to the hot position. But I won't rule out that it may be that.
Lead Driver
Joined: Nov 2013
Posts: 7,160
Likes: 1,169
Two options:
1) Shrink yourself down to a very compact size and position yourself under the hood while a helper drives the truck. Please use extreme caution due to the hot exhaust manifold, radiator fan, etc.
2) Remain your normal size and go for a test drive to duplicate the cold condition. Pull over and shut the engine down as quickly as possible and see if the hoses are still not hot enough.
Either option will work, but the second one is probably more workable.
Moderator
Joined: Jan 2001
Posts: 56,971
Likes: 2,729
From: Virginia
Okay. Maybe I overreacted. I could hold on to the hose maybe not for long but I mean you could touch them and then say okay the heater should be warming up now. I wouldn't think it would be a blend door problem because the cable to the lever was broken when I got the truck and is stuck to the hot position. But I won't rule out that it may be that.
I can't believe I am asking this, but is your factory temp gauge somewhere around the "o" in the word "normal" on the gauge? Most of the trucks I have driven, this is about 190 degrees.
Thread Starter
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Laughing Gas
Joined: Dec 2010
Posts: 924
Likes: 1
Good point, but I'd add one caveat. Can you check the hose temperature immediately after driving? Could be while driving, the coolant temp drops somewhat, like with a thermostat not fully closing and all that airflow through the radiator. Then you test while stationary, and without all that ram airflow through the radiator, the heater hoses feel hot.
Two options:
1) Shrink yourself down to a very compact size and position yourself under the hood while a helper drives the truck. Please use extreme caution due to the hot exhaust manifold, radiator fan, etc.
2) Remain your normal size and go for a test drive to duplicate the cold condition. Pull over and shut the engine down as quickly as possible and see if the hoses are still not hot enough.
Either option will work, but the second one is probably more workable.
Two options:
1) Shrink yourself down to a very compact size and position yourself under the hood while a helper drives the truck. Please use extreme caution due to the hot exhaust manifold, radiator fan, etc.
2) Remain your normal size and go for a test drive to duplicate the cold condition. Pull over and shut the engine down as quickly as possible and see if the hoses are still not hot enough.
Either option will work, but the second one is probably more workable.
Your hoses should be really hot, you can't hold onto 190 degree hoses for very long. If you can hold onto them for a little bit, the engine is not getting hot enough, your thermostat theory might be valid.
I can't believe I am asking this, but is your factory temp gauge somewhere around the "o" in the word "normal" on the gauge? Most of the trucks I have driven, this is about 190 degrees.
I can't believe I am asking this, but is your factory temp gauge somewhere around the "o" in the word "normal" on the gauge? Most of the trucks I have driven, this is about 190 degrees.
We'll scratch the temp gauge question be cause I know it isn't accurate at all it says I'm over heating when driving and then I shut it off and turn on again and will read normally
FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
Your heater core may be plugged. Just cleaned one for a buddy with a '91 F150 and the heater will now run you out of the cab.
What happens is that the little tubes in the core get plugged up with gunk and the flow stops, either partially or completely. In order to find that out, check to see if one hose is hotter than the other. That indicates poor flow. If so, you know the hot one is the input and the cooler one is output. You want to reverse the flow to backflush the core, but not put the gunk back in the cooling system. So pull both hoses and loosely couple a garden hose to the output side. LOOSELY! City water pressure is usually 60-100 psi and the heater core is designed for 15. Then turn the water on slowly and watch the gunk come out the input side.
What happens is that the little tubes in the core get plugged up with gunk and the flow stops, either partially or completely. In order to find that out, check to see if one hose is hotter than the other. That indicates poor flow. If so, you know the hot one is the input and the cooler one is output. You want to reverse the flow to backflush the core, but not put the gunk back in the cooling system. So pull both hoses and loosely couple a garden hose to the output side. LOOSELY! City water pressure is usually 60-100 psi and the heater core is designed for 15. Then turn the water on slowly and watch the gunk come out the input side.
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Thread Starter
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Laughing Gas
Joined: Dec 2010
Posts: 924
Likes: 1
Your heater core may be plugged. Just cleaned one for a buddy with a '91 F150 and the heater will now run you out of the cab.
What happens is that the little tubes in the core get plugged up with gunk and the flow stops, either partially or completely. In order to find that out, check to see if one hose is hotter than the other. That indicates poor flow. If so, you know the hot one is the input and the cooler one is output. You want to reverse the flow to backflush the core, but not put the gunk back in the cooling system. So pull both hoses and loosely couple a garden hose to the output side. LOOSELY! City water pressure is usually 60-100 psi and the heater core is designed for 15. Then turn the water on slowly and watch the gunk come out the input side.
What happens is that the little tubes in the core get plugged up with gunk and the flow stops, either partially or completely. In order to find that out, check to see if one hose is hotter than the other. That indicates poor flow. If so, you know the hot one is the input and the cooler one is output. You want to reverse the flow to backflush the core, but not put the gunk back in the cooling system. So pull both hoses and loosely couple a garden hose to the output side. LOOSELY! City water pressure is usually 60-100 psi and the heater core is designed for 15. Then turn the water on slowly and watch the gunk come out the input side.
Would this happen to a new heater core as well?
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FTE Legend
Joined: Nov 2015
Posts: 30,870
Likes: 4,112
From: Angier, NC
Take the guessing out of the picture with this.
Non-Contact Infrared Thermometer With Laser Targeting
You can see what the inlet & outlet hoses of both radiator and heater core.
You can also see the temp coming out of the heater.
I should get one someday.
Dave ----
Non-Contact Infrared Thermometer With Laser Targeting
You can see what the inlet & outlet hoses of both radiator and heater core.
You can also see the temp coming out of the heater.
I should get one someday.
Dave ----
Thread Starter
|
Laughing Gas
Joined: Dec 2010
Posts: 924
Likes: 1
Take the guessing out of the picture with this.
Non-Contact Infrared Thermometer With Laser Targeting
You can see what the inlet & outlet hoses of both radiator and heater core.
You can also see the temp coming out of the heater.
I should get one someday.
Dave ----
Non-Contact Infrared Thermometer With Laser Targeting
You can see what the inlet & outlet hoses of both radiator and heater core.
You can also see the temp coming out of the heater.
I should get one someday.
Dave ----
FTE Legend
Joined: Nov 2015
Posts: 30,870
Likes: 4,112
From: Angier, NC
You should be able to tell where the heat is going with it.
Dave ----
Lead Driver
Joined: Nov 2013
Posts: 7,160
Likes: 1,169
Take the guessing out of the picture with this.
Non-Contact Infrared Thermometer With Laser Targeting
I should get one someday.
Non-Contact Infrared Thermometer With Laser Targeting
I should get one someday.
https://www.amazon.com/FLIR-TG130-Sp...NB86GVFQQQFK5B
I picked up a refurb unit for $175 a couple of months ago. This thing is absofrickinlutely amazing. Not only can you take a temp reading, but you can also quickly see heat gradients. No more poking around looking for hot or cold spots, it shows relative hot and cold within the field of view. I've been thinking of adding a product review, but can't seem to find my round tuit.
