Poor Heat in Both Front & Rear Units

[RDEXPO02]

I have a 2002 Expedition 5.4L 99K mi runs great. Coolant levels are fine, no leaks, never had to add anything to it. Temp gauge comes up like normal within 3-5 min it moves, then goes to 1/4, then when warmed up and stays where it has been for the many years I've owned the vehicle (since new) right about half way (maybe a smidge more) after about 15-20 min.

Heat on a day in this cold winter just doesn't cut it anymore. One day its luke warm and other days (only when outside temp is above 40) works just OK that I can take my jacket off on long drives and be comfortable but I leave the heat on 90 all the time. I use to be able to remote start the car once or twice and melt 4 inches of snow off the car, the windows, completly de-ice and dry the windshield and almost melt away the snow on the top of the car. I was sweating! Now this problem started a few weeks ago all of a sudden....

I read things on the blend door being stuck or broken leg, but when I change the temp from 90 to 60 using the manual temp control I can definitely feel the difference of the cold air coming in and then back to warm when I go back to 90. I can feel it as I gradually change the temp or do it more rapidly. Lines are all hot (can touch and hold them just fine) but hoses don't have any pressure to them to me. I squeeze the upper radiator hose easily and it makes the level in the degas tank move a little with NO BUBBLES. I squeeze the heater lines and they feel hotter than the radiator hose but almost like nothing is in them, no pressure. Not sure if they did before or not because I never had this problem before.

Today it is 38 degrees and I have a temp gauge saying I have exactly 90 degrees coming out the defrost vents but to the touch it doesn't feel it and its not enough to melt any snow or ice off the windshield even after running the car for almost an hour. Today there is no ice so can't test it really but the colder it is outside the less heat is is inside. Its barely warm when it is 5 degrees but its not ice cold air coming out of the vents, its just barely warm and barely enough to take the fog away on defrost.

I've read about bad water pumps and air in the coolant system but with metal propellers and no overheating and factory idiot gauge within the norm I doubt it. Same thing with a suspected thermostat I think I would be seeing something even though its just a factory needle gauge if it was stuck closed. I don't think it is stuck open because it would take almost forever to move the needle gauge to normal range and probably would be less than normal.

Any ideas on things I can do to check? There is no heater control valve, just a blend door from what I see and read on the web. So what tells the coolant to flow through the heater box and into the heater core? Fans are blowing, air is moving, its just not very warm. I can even stick my fingers in the degas tank as the coolant after just now running for an hour and a half is only 91 degrees. Is this just the engine temp warming it up being just an overflow tank or is it suppose to be as hot as the radiator and flow in and out and I'm suppose to see it turning up every time the thermostat opens up?

Heater lines feel hot like there suppose to but don't feel full and kind of soft. Ran the car with degas tank open for all this time (1 1/2 hours) and put a piece of tape on the level line (2 inches above cold mark and an inch from over flowing) and it has never moved unless I squeeze the hose. But when engine is cold it drops to just above cold mark and goes back up 2 inches when warm. Had the heat at 90 the entire time and I got in and it was just comfortable but not a sweat box as expected and should have been.

Any ideas?

Thanks in advance

 

[stamp11127]

If you have access to an ir temp gun I would check the temps of upper and lower rad hoses plus the heater hoses once the engine is up to temp.

The ir temp gun is the pistol grip temp guns with the red dot laser pointer.

 

[bedrck46]

check along the full length of the heater hoses you should feel about the same temps on both hoses. also the temps should be above a point where you can not hold them If you notice a difference in the temps anywhere the hoses you may have a blockage.

From the sounds of it I would suspect that the T/stat may be stuck open or that the water pump isn't pumping as it should be.

With you saying that the temp in the overflow tank is only 91 deg tends to make me think the above is your problem and if you can hold you hands on the heater hoses after running for over an hour would also tell me your not getting to temp

What would be nice would be if you had a obd2 scanner that would tell operating conditions

 

[RDEXPO02]

I have an actron cp9580 OBD tool, use it for codes and bought one last time I had a coil go out to tell me which one. Not sure if it will do temps or anything.

The hoses are more hot than warm, but with temps in the 20's and 30's I have no problem keeping my hand on the hoses. The heater core lines feel hotter to me. Maybe cuz they are smaller diameter and hold heat in better or dissipate it more easier....

I felt the hoses from the water pump to the fire wall and they were steady temp all the way through. It was a little hotter than what was coming out of the ducts but not like night and day.

Does anyone know if the Actron scanner I have will read what your asking?

Is the overflow tank suppose to circulate what is in the cooling lines or is it just an expansion tank or over flow when needed and closed otherwise from the flow.

 

[stamp11127]

If the scanner does read temp, it will only show what the coolant temp sensor is reading. Not what is going in and out of the heater core and radiator.

 

[bedrck46]

were you able to hold you hand on the hoses for any length of time and if so how long

 

[bedrck46]

I have the 9580A and can read coolant temp. Lately I have been using a obd2 blue tooth reader and the Torque Pro app paired to a tablet or smart phone I find it easier to set up and get different readings

 

[RDEXPO02]

Yes, I can hold the hoses just fine. They were warm, just not burning hot.

Its seems hotter at the heater hoses going into the core, not burning or anything but much warmer than the radiator hose. If the thermostat was stuck open, why would the temp gauge come up in shifts like normal though? It would take forever to warm up wouldn't it? I see the temp gauge at regular mark but that heat just isn't coming inside and off the heater core.

I bought a 192 thermostat yesterday but they didn't have the right O-Ring, going to local store in town today and gunna swap it out in a little bit just for kicks. Shouldn't take too long at all. It is the original TS as well the water pump from 2001-2002 when the car was made so who knows.

I was thinking though, does the cooling system flow open into the degas tank on each cycle? Or is it just a "just in case" where the pressure builds up or something in the hot summer months? Should I see circulation in the tank each cycle? And If the TS was open wouldn't I see it all the time?

Thanks

 

[Mangina]

If the thermostat was stuck open, why would the temp gauge come up in shifts like normal though? It would take forever to warm up wouldn't it? I see the temp gauge at regular mark but that heat just isn't coming inside and off the heater core.

Thanks

It might not behave that differently since you aren't getting very cold weather. It could only be taking an extra minute or two to warm up which you might not even notice.

Thermostats are designed to fail fully open. I've never heard of one failing closed, so that's where I would start. Its a guess, but its a cheap and easy place to start.

 

[bedrck46]

If you can hold the hoses I would say your temps are lower than 120 degrees. The overflow tank is in the water circuit but you will not see circulation in the tank as it only has One hose which allows for coolant to either enter into the system or allows for the expansion of the hot water to enter into the overflow tank. If possible could you take a picture of your temp gauge before you put a new T/stat in.

 

[splintrcel]

I had some guy at a quick lube at a ford dealer dump green coolant in my stock colored coolant and turn it brown and screwed up my whole coolant system. The EATC module temp indicator is only the desired temp setting, not what the car actually is putting out. If you have clean coolant its prob the thermostat. If that doesnt work you can try the water pump but its a two man job to get the fan off. Its just a pain in the ass. You will need to 1/2" drive breaker bars. Loctite the pulley bolts back on as well, mine fell off even though i had it tighter then they were when i pulled them off. If the water pump is good and coolant is clean and thermostat is changed, it could be the heater core which is a pain but doable but if the heater hose isnt hot going to the heater core you can probably avoid changing the heater cores. I live in wisconsin and lately it has been around 0 degrees or lower so having working heat is pretty important. Even when its -14 out my heat still cranks out so there has to be something up with your system. If and when you have to dump coolant to save your self swearing and a mess only open of the coolant release valve to the point where its just a solid stream and no farther. It will be slow to dump but it will keep the stream landing in the drip pan instead of spilling everywhere.

 

[RDEXPO02]

I hooked up my little test computer, it is an OBDII and does do real time temp readings and not just read codes. Paid 249.99 at Autozone last time my GF had a problem with her car. I watched it warm up and it went as high as 195 (199 for a few seconds) and dropped to 184-190 range (revving and holding RPMs at 2K but never got hotter and now I can't get it above 187 even holding the RPMs up. It has been at 187 for the past 40 min. Have not been to auto parts store yet but will soon.

Also I plan to drain and change antifreeze and do a flush myself. I bought two small bottles of FLUSH at Napa and I'm defrosting the hose in the tub now.... LOL... I think the antifreeze that is in it now is orange but I bought 2 gal of PEAK Global antifreeze that is suppose to mix with any color. I was just going to use that exclusively after everything is flushed out so it won't be mixing with anything but clean water when I'm done. Being that I am not mixing colors so as long as I have the same color its alright from what I heard from everyone I talked to thus far. Right now it looks more BROWN than orange from whatever the oil change places have added over the years but at every oil change they test it and they say its good with those beads that float in the test tube thingy!

I saw a video on you-tube where a guy had an expedition and broke the heater line off the top of the manifold, installed a TEE with a few inches of hose and never had to cut the line. He hooked up a 1 1/2 PVC and stuck it in the degas tank and slowly put water in it till he got it flushed out with NO LEAKS or spills. I already have my TEE and a few feet of heater hose O bought, have to run to storage for the larger PVC at the degas tank and see if what I got fits tight. I'm gunna try what he did with a few modifications. I am going to actually use FLUSH solution and when I'm done I'm going to release the bottom hose of the radiator (when I know its just water in the system) and let it run onto the ground outside because any debris will kind of stay toward the bottom. if there is anything that comes out or dislodges from the hoses running plain water for a few min in the driveway where I don't care if it ices up won't go into the well or harm any pets or animals and get it all out.

http://www.youtube.com/watch?v=oUWJU5hvlYs

It's 29 degrees outside btw

Does that help at any guesses?

 

[bedrck46]

From the sounds of it your t/stat may be sticking open I just had the same thing happen on my 01. I had mine hooked up when I took a recent trip to Texas and that's about the best temp I could get and it was warmer outside then. But when the temps here in PA took a drop into the single digits the best I could get on the OBD2 was about 170. Since I changed the T/Stat I can now get up to 212 deg See the attached pic posted earlier That was with an outside temp in the low 30's

Also most on here recommend using a Motorcraft T/Stat

 

[bedrck46]

btw if you can hold you hand on a heater hose for longer than a minute I would say the tem is 120 or less I know what I am able to hold Think of it as if you were holding you hand under the water at the kitchen sink and when you find the temp that you can't keep your hand under the water flow put some in a glass and take the temp you will get a good idea of what you can hold Its not the best method to use but it will give you a ball park idea

 

[splintrcel]

Its a bad sign if you have brown coolant. I would say someone dumped in green. The green interacts with the orange creating this rust colored shit that fills up the entire system. Once you drain the coolant pop off the main radiator hose and look to see if there is crap in there. If there is good luck have fun because that crap is probably all over the cooling system. I had this issue and in order to fix it i flushed the coolant twice, swapped thermostat, water pump, and front heater core. I also ran an additive to my new coolant (Prestone green). My rear heater core is also getting replaced but i will get around to it. There is a clear difference between the two heat out puts so my heater core was def clogged with crap. My front core actually sprung a leak from the flushing so keep that in mind as a possiblity. When doing the flush, DO NOT USE THE PRESTONE T FLUSH KIT!!!! It leaks with in 3 months and a new coolant line is like $40.

 

[RDEXPO02]

OK, I swapped out the T-Stat and it wasn't that bad. When I took the hose off it appeared to be closed because when I popped out the O-ring it started to come up from the block. Upper hose appeared to be full as almost half or a full gallon spilled out from it. No debris or sludge or any particles did I see. Pressing on it it feels fine almost like the new one that went in.

Here is the old one I took out



Fluid that spilled out was a slightly darker orange than the orange stuff I had, it had a little brown tint to it but was definitely orange and could tell not so brown as I thought. Guess looking into the degas tank made it appear darker than it really was.

Didn't do the flush, can't find my piping and stuff to do it like the video, and have it all buttoned up now. Got the car running for almost an hour again and it seems a little warmer now out of the vents but it also went up to 33 degrees here (from 26 this morning when I tested last). A good quality temp gauge says its 84 degrees in the car with the heat blasting for over an hour and the doors and windows closed up. That is better than 60 or so which was about the best I could get it before, but that was on a day it was only 10 degrees outside when I tested that. Heater was barely defrosting the window, had to drive with windows open.

OBD said that BEFORE the T-Stat was changed coolant was 185 and stayed there for an hour and only went up or down a degree or two 184-187



After the T-Stat went in, it only went up a few degrees. I got it up to 199 for a second or two revving and holding it at 2500 or so. But now it stays at 192-194 or so (more so rock steady at 192) for past hour. Not a huge difference really I think but it did rise up a few degrees from 185 and stays at 192 for the past hour rock steady.



But it does seem a bit warmer now... (but it isn't 10 degrees outside yet) have to see what it does when its zero or -10 again. Maybe the lines need to be flushed, but why a water pump? How do metal propellers go bad?

FYI - factory temp gauge is right at where it was before, almost dead center in the middle from slightly above center (but again it is a factory idiot gauge). I can hold the heater hose for almost a half min, its not hot hot hot but I can almost take it for a half min or so. No pressure in the lines at all, I can squeeze them just fine including the upper main radiator hose. Main hose I can hold all day long, just warm... Heater hose gets a little uncomfortable but not like I'm touching something almost 200 degrees. Maybe the thick heater hose and ambient air is providing a sort of cooling effect insulated it from what it really is. Don't have an IR temp gun.... maybe the next toy I buy.

Does any of this help at all?

I'm gunna have to fill up again, gas station is going to love me!

 

[bedrck46]

looks a little better leave you OBD2 hooked up and the take the expy out for a ride of about 15 miles and keep an eye on the coolant temp I was having about the same problem as you are and after I changed the stat my temps were up to 212 deg

 

[Cobra Jet]

Your fix may lie within this thread:

1999 Expy 4.6 Heat FIXED! - You won't believe how! - Ford Truck Enthusiasts Forums

Look for the heater flow restrictor fitting within the supply heater hose that is found at or near rear of block on passenger side. You can feel it inside of the the hose when squeezing the hose or running your hand down the length of it.

Remove it.

No, it won't harm anything. No it won't "blow out your heater cores".

Ford placed these same restrictor fittings in many of their vehicles - and it was common in early Mustangs too (79-93 era). The fitting is small and the center of the fitting has a smaller opening in it. Over time, the fitting can get clogged, thus reducing coolant flow through the hose with the restrictor. This can lead to lower than normal cabin temps when heat is being used.

This part came already installed in the factory supply hose. When a shop (non-Ford) R&R's the original hose for a coolant job, 99.9% of the time the original hose with restrictor is tossed and a new hose (w/o restrictor) is installed... Most people don't even know the hoses had one of those restrictors inside anyway.



Try it and report back...

 

[RDEXPO02]

I saw and felt it. You can almost see it in the hose bulging a tiny bit. I thought it was something in the hose to keep the "bend in it". I knew it was a metal insert and not a clog and obviously from the factory and didn't think to mention it. I read the thread and it said that it was needed for the front heater core more so than the rear and especially for the DEFROST vents or something. I don't think I'm gunna mess with it. I'll see how the temps do while driving.... I'm going out again at 4:30 and I'll hook up the OBD and watch it.

I still don't think it was the thermostat, I mean.... an hour and its only 84 degrees in the car? I should be sweating with front and rear heaters going!

Here is the flow restrictor...

 

[Mangina]

I still don't think it was the thermostat, I mean.... an hour and its only 84 degrees in the car? I should be sweating with front and rear heaters going!



View attachment 8042

My truck never fully warms up when I just idle it. It needs to be moving before it gets fully warmed up. Does it get hotter once you drive it?