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Heater not getting hot? Heater not working?

Tiny
CMYZGOFST
  • MEMBER
  • 2002 LINCOLN LS
  • 3.9L
  • V8
  • 2WD
  • AUTOMATIC
  • 130,000 MILES
Still no heat; replaced the thermostat, thermostat housing, dual climate control valves, vacuum leak test, vacuum filled the cooling system. Please let me know where to go from here.
Sunday, November 11th, 2018 AT 12:03 PM

24 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning.

Did this engine overheat? If it did, it could be a failed head gasket. One of the signs for a failed head gasket is no heat and the lower hose is cold.

A leak down test on the cylinders will tell you if a head gasket is leaking into the cooling system.

Is there a lot of pressure in the system?

Roy

https://www.2carpros.com/articles/head-gasket-blown-test

https://www.2carpros.com/articles/car-heater-not-working
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Monday, November 12th, 2018 AT 3:37 AM
Tiny
P_LUCK
  • MEMBER
  • 1 POST
  • 2002 LINCOLN LS
  • V8
  • 2WD
  • AUTOMATIC
  • 130,000 MILES
My 2002 lincoln Ls v8 blows cold air out the vents but the heat wont work. The car is reaching normal operating temp not over heating so I dont think its the thermostat. Plenty of coolant I check every fuse in the car. What should I do next?
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Need to test the heater hoses. They are slightly hidden so I attached the process from the manual below to access them.
With engine running and at operating temp heater fan motor on high open hood and check heater hoses by the firewall
if both hot you have a blend door issue CHECK FOR CODES
if one warm or hot and other not heater core need to be flushed
isolate heater core and flush
let me know
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Pump location
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
AIARDO24
  • MEMBER
  • 1 POST
  • 2002 LINCOLN LS
  • V8
  • 2WD
  • AUTOMATIC
  • 138,000 MILES
My heat in the car blows cold air but when I drive the car with the rpms up it stats to blow hot air
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If not too hot to hold, then you have to look at the actual engine temp and if that is up, then your looking at a restricted heater core.
If you find that they are both too hot to hold, then the heat in that vehicle is controlled by a blend door that regulates heated air flow. It is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.
If they are both not too hot to hold on to, then you either have a restricted heater core or the system is not completely full and getting air pockets for some reason.
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
SHELLYN007
  • MEMBER
  • 1 POST
  • 2002 LINCOLN LS
  • 3.9L
  • V8
  • 2WD
  • AUTOMATIC
  • 120,000 MILES
Heater does not work, I did self test and got a code on heater screen [ 12 42 ]? How many air bleeders is there? I found one. Air works good, just on heat. John
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
DANNY L
  • MECHANIC
  • 5,648 POSTS
Hello, I am Danny.

The code you have mentioned B1242 is affecting the "re-circulation door actuator circuit failure". The test needing to be performed is to check for incorrect/erratic direction of airflow from outlets. Basically by the actuator not working, it is not allowing a blend door to open/close and allow air to move where it is supposed to be directed. I can attach testing info but it is 19 pages. The actuator is located on the HVAC assembly behind the right side of the dashboard. This requires a fair amount of disassembly/tools for checking. I attached a picture of the actuator and hope this helps. Let me know if more information is needed or any other questions.
Danny
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
SHELLYN007
  • MEMBER
  • 1 POST
Hi, this is John do you live in Colorado?
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
DANNY L
  • MECHANIC
  • 5,648 POSTS
Hi John, Danny here. No, sorry, I am in California. Do you have any questions or need more information about the heater problem?
Danny-
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
TOCSMOM
  • MEMBER
  • 2 POSTS
  • 2001 LINCOLN LS
Heater problem
2001 Lincoln LS V8 Automatic 110000 miles

I turned my heat on, however, it only blows out cold air. Also, the heated seats do not work. What are some possible causes?
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
SLICX
  • MEMBER
  • 9 POSTS
There are a few possible causes that can produce a no heat problem. One and the most likley cause is that you blend door is not operating properly. The blendore is exactly what it sounds like its a little door in your dash that switches back and forth and changes the amount of hot or cold air that passes through the vents. Another less likley cause is that your heater core is stopped up. The heater core is a box in your dash that hot coolant from the engine passes through then air is passed through the heater core and voila hot air. It may be possible that either the heater core itself is blocked up in which case you have to replace the core or a valve that controls the coolant flow to the core is not opertating as it should.

In response to the heated seats it could be a number of things. Such as the electric heating element in the seat, the operating switch is faulty, a problem with the wiring, or a bad power source. Any of these is a likley cause and an automotive technician or a person you know that has an undestanding of electrical circuts and a means of testing them could probably diagnose these faults further. What you could do is verify that the fuse is good. Check the fuse panel and look at the diagram either in a service manual or on the back of the fuse panel cover and see if you can find any one labed seat heater, heated seats, power seats, or any thing that may fall in that catagory. Pull the fuse out and look to see if it is blown. You can tell by tha little "s" shaped wire on the inside is burned or not connected, if its blown then replace that fuse with one of the same rating, you can find the ratting at the top of the fuse ie 10 20 15 30 35. Also I would chaeck and see if both seats dont heat up if they dont then its probably a common problem like the power suply or wiring. Hope this helps.
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Sunday, October 25th, 2020 AT 11:51 AM (Merged)
Tiny
2CP-ARCHIVES
  • MEMBER
  • 4,540 POSTS
  • 2000 LINCOLN LS
  • 164,000 MILES
My car and my heater blows cold air and only cold air. Help me diagnose my problem
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Check coolant level, thermostat, heater hoses for being hot going into the heater core, blend door motor or possible blown head gaskets from overheating

check exhaust system for leak for your smell.

Roy
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
BOOANDMAW1613
  • MEMBER
  • 1 POST
  • 2000 LINCOLN LS
  • 164,000 MILES
I just changed upper radiator hose because the it had a leak and was overheating. Now after replacing hoses my heater only blows cold air, and it smells like exaust fuems in the car.
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
You have not bleed the cooling system, run with heater on and place a bottle upside down with the bottom cut out in the coolant tank keep this topped up as a head, air will work its way out, when the heater runs hot that should do it.
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
CHER4272
  • MEMBER
  • 1 POST
  • 2000 LINCOLN LS
  • 3.6L
  • V8
  • RWD
  • AUTOMATIC
  • 150,000 MILES
I had the lower and upper radiator hoses replaced the heater was working great before they were changed and its blowing cold air.
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 33,871 POSTS
Most likely there's an air pocket that hasn't bled out yet. Do you have a dash gauge for engine temperature? If you do, is that reading normal? If the engine is overheating, look on the thermostat housing to see if there's a bleeder screw.

Also feel the upper radiator hose once the engine is warmed up. It should be too hot to hold onto for very long. If it is, feel the heater hoses. If they are hot too, suspect an actuator problem on the heater box. If those hoses are cool, the heater core might be plugged, but it's more likely the coolant level is low or there's air in it.
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
BLAQ77
  • MEMBER
  • 2 POSTS
  • 2000 LINCOLN LS
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 157,000 MILES
The cylinoids are stuck or not working. The fuses are ok thermostsat has been replaced. What is the easiest way to remove and replace?
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Its the blend door motor (actuator )
no easy way about it
have to remove the instrument panel to reach it
good luck
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Sunday, October 25th, 2020 AT 11:52 AM (Merged)

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