Poor Heat in Both Front & Rear Units

[RDEXPO02]

I have owned the car since new. Remote started the car in winter and melted several inches of snow off the car and even melted some on the roof. Just from idle starting it once and then again a second time.

Now I run the car for an hour straight buttoned up tight and its 80 at best? Only when its above freezing outside? 60 at best other days when its in the teens or at or below zero.

Once I get driving, I guess I get used to it, and as the air recirculates again and again and again I guess it would get hotter but can't say definitely from driving or not.

I monitored the car temp and it was 194 - 200 and once hit 201 but 90% of the time it was at 197-199

 

[bedrck46]

what is the temp rating on the new T/stat

 

[RDEXPO02]

195

 

[bedrck46]

I would expect to see engine temps of 205-212 deg after driving at 50 mph for about 20 minutes It will drop some with a decrease of speed. You may have a blockage in the heater hose as was mentioned earlier or possibly a clogged heater core or may need a new water pump. One other thing to consider is if the blend door isn't fully closing that also could cause colder cabin temps.

One other item you could try is to take some cardboard and block off the lower part of the radiator to see if that has any effect on temps

 

[JUST4FUN]

If your buying Stant Tstat pitch it in the garbage go to ford a get the one it was born with. I'm not a fan of anything stant , I have go down that road never will go back

 

[bedrck46]

If your buying Stant Tstat pitch it in the garbage go to ford a get the one it was born with. I'm not a fan of anything stant , I have go down that road never will go back

I just changed mine and was going to get a Motorcraft but a friend had a NAPA stat that he didn't use and being the cost was free I decided to use it so far it has solved my problem however I do plan on a Motorcraft when it warms up again. To cold for these old bones to be out working on the expy.

 

[RDEXPO02]

****** UPDATE ******

12 degrees this morning.... NO (or poor) HEAT

OBD says temps are 192-199 while driving... it might seem that I was getting more heat from the vents if I was holding RPMS at 1500 to 2000 or surging but maybe that was wishful thinking, I dunno. Is there a way to test water pump pressure? Is it possible to have a "weak" water pump that does not leak?

What if I broke the heater line and put a clear piece of hose to view flow or something?

Any ideas? Its too cold for me to slap a water pump in myself, the only alternative is FORD dealer or "Joe Schmoe" that does repairs in his backyard around here for me.

Also, I read all the strangest and bizarre posts about flushing. How the flush chemicals dissolve rings & seals behind the dash and how it leaks there after costing 1,000 or more to remove the dash to access the heater core and blend door area..... Had the car since new, never leaked prior, never used any stop leak or any other products added to coolant.

To flush or not to flush? And how can I do a test to see water pump pressure/flow?

Thanks in advance

 

[bedrck46]

I know this has been asked before but what are the temps off the heater hoses going from the pump to the heater core and the return from the heater core

Was 7 deg here at 4:30 now at 15 deg

 

[RDEXPO02]

I don't have an IR gun, but on days that it is working I can hold the heater lines for maybe 20 seconds till it gets uncomfortable, maybe 30 seconds if I "try to be a man" LOL... I wouldn't say its anything close to "blistering", but it does get hot enuff that I let go. I would say on average I can grasp hold for about 30 seconds before it gets "uncomfortable".

Temp from the vents blowing inside the car claim they are 90-91 degrees but it just doesn't heat the car up.... You know when you have the panel vents blowing heat and you have the one vent close to the drivers window blowing on your hand if your holding the steering wheel at 10 & 2... well... it doesn't bother or heat up mu hand that I have to close the vent or re-aim it at all. But if you feel the air from the vent, it's warm....

 

[bedrck46]

I take it you have automatic controls for the heater/AC system
It is very possible that the blend door or a vacuum door is sticking. Air inlet door

A IR gun would be great but another way to check temp would be to take a meat thermometer and tape it to the heater hose and also add a little insulation around it so that it reads the hose temp and not any air temp Not the best way but will give a better idea as to the temp

Measure both inlet and outlet houses

 

[bedrck46]

The following information was copied from the Ford service manual

Condition===Insufficient, erratic, or no heat

Possible Sources
Low engine coolant level.
Engine overheating.
Plugged or partially plugged heater core.
Temperature blend door binding/stuck.
A/C electric blend door actuator.

WARNING: The heater core inlet hose will become too hot to handle and may cause serious burns if the system is working correctly.
NOTE: Be sure that the inlet hose flow restrictor is in place and is undamaged.


Allow the engine to reach normal operating temperature.
Feel the heater core inlet hose.

Is the heater core inlet hose too hot to handle?

 

[RDEXPO02]

Ok, here is what I tackled just now....

I cut the heater line and removed the heater flow restrictor part of the line with a few inches of heater hose I bought at the auto parts store. I started up the car and within a few min I could not touch the part of the line I put in. Obviously the insulating properties of the aftermarket hose are nothing like the factory lines. You can feel a difference of night and day between them... I cannot hold the new piece of line for more than a few seconds but the factory line I can hold for almost 20-30 before it just gets uncomfortable.

When I removed the line I blew into it with my mouth (part going into dash and TEE for rear) and water came right up to manifold where it plugs in on top. So I guess that rules out blockage right?

I did not check this before, but I did mention that there is no pressure in the lines. Not even in the top hose after the car has been idling for over an hour or the heater line.

This time I thought to raise the idle at the throttle body while holding the hose and sure enuff it fills the hose and you can feel the surge each and everytime. People say it won't blow out my heater core or seals as they did this to theirs. But if the hose was hot just from idle "something" is flowing through the line even when it's not hard from water flow and completely filed.

How much pressure is suppose to be in the line at idle?

Sitting in the car, at idle feeling the heat from the dash it is just warm (but temp gauge claims its 90-91 degrees (not car dash but HVAC meat type thermometer I use in the vent).

Even if I idle the car to 1500-2000 and hold it (knowing now I have MUCH more flow into the lines) the heat does not increase in the vents a bit. Not from what I can feel or from what the thermometer says either. But it just doesn't heat the car. My feet are like ice cubes! Its like using a bic lighter to heat a room. The flame is hot, its a few hundred degrees.... but it just isn't enough to heat a room is it? My Blower is fine, air is circulating, I have DUAL heaters front and rear... blowing just as strong as I remember, dash says there is 90 degrees coming out, temp gauge stuck in the vent says it 91 degrees but it is not heating the car or even warming my hands when I place them in front of the vents.

Blend door is working I guess... as I can change the temp on the dash control and hear the air difference when I go back to 90. It even blows a little harder.... Just a little.... and you can feel it go to cold and back to warm when I adjust temp from 60 back to 90 and vise versa....

any ideas?

 

[bedrck46]

This concerns me
"Blend door is working I guess... as I can change the temp on the dash control and hear the air difference when I go back to 90. It even blows a little harder.... Just a little.... and you can feel it go to cold and back to warm when I adjust temp from 60 back to 90 and vise versa...."

Try running the controls in manual rather than in automatic place the controls on defrost/floor and see if that makes any difference

 

[RDEXPO02]

I only run it in manual. I never use automatic. I said "I Guess" cuz I can't see it but can feel the obvious temp difference when I lower the temp (manually) and feel the blend door opening as the cold air comes in.

I was referring to when "I" change the temp controls I can feel the cold air start to come in and get colder and colder and colder to like the AC was on when I get to 60, then like warm at 70 and you can hear the dash close and the air flow makes a noise (like when you hit the recirculate button on cars that have it).

I mean I guess the blend door could be leaking after all these years the foam dried out.... but it's anyone guess.

Is there suppose to be pressure in the upper radiator hose?

FYI - Just put the original line back with the restrictor valve. I didn't like the surge and feared it must be there for a reason. Didn't want to open up another can of worms....

 

[bedrck46]

yes there should be pressure in the system I don't know the exact pressure but the overflow cap should be 15 PSI and would relieve pressure if it exceeds that. Again would be nice to know the temp of the inlet and outlet hoses

 

[Mangina]

Another cheap fix you could try is replacing the rad cap. Maybe coolant expanded into the overflow tank and the rad cap is keeping it from going back into the rad when it cools?

You could also have a partially clogged heater core from the sounds of it. Hopefully not though.

I'm just trying to throw out cheap fixes.

 

[bedrck46]

need for you to check the following fuses #8 and #13 Do not check them by looking at them USE a meter to check fuses

 

[RDEXPO02]

ALL FUSES GOOD

Checked both under the dash and in engine compartment.

Now if I have water flow, hoses are hot, why would BOTH front and rear heaters just be luke warm? There isn't a blend door for the rear unit. And if there was by some chance, both go bad? Why is the temp just warm and not hot enuff to melt the ice off the windows and keep me warm inside?

I can understand if the blend door was leaking in the front, but the rear too? Temps feel the same. I can breath on my hands and the heat is hotter and noticeable diff of night and day.

I am just stumped.... and to pay ford 85.00 an hour for diagnosis (that does not come off the repair cost) is ridiculous.

Please think of something.... Thanks...

 

[bedrck46]

FYI The rear unit does have a "Temperature blend door" and a "A/C damper door"

The front heater box does contain 4 doors The blend door is electrically controlled the other doors are vacuum controlled. It could be possible that the vacuum system has a leak or broken hose and that those doors are not moving.

At this point I would suggest a new water pump also that would be much cheaper than
$85.00/hr provided you do your own work.

You may also want to obtain a;
Ford workshop manual on DVD. Can be obtained from seller "morpheousking" on e-bay. Cost about $10.00 Much better than Clymer, Haynes or Chilton and also includes wiring diagrams

Don't waste your money on a Clymer, Haynes or Chilton Manual.
It is well worth the $10.00 just make sure you get the DVD for your year as the seller has different DVD's for different years

 

[bedrck46]

If you can send me a private message with your e-mail address and I will send you some prints of your system