Hello Im new to the site today! signed up for a silver membership figuring theres a lot of smart guys on here that can help me and I have two ford vehicles and have always owned ford pick up trucks.

Ok introduction aside, heres my current issue...about a year ago I had my radiator on my 02' e-250 econoline van changed out at a mechanic shop after it went on the highway and had it towed there by triple A. When i got the van back i had no heat and the heat/air would transfer to the default defroster mode. So i suspected a vacuum issue. found a youtube video that showed me how to bypass the check valve that goes through the passenger side firewall. That fixed the problem of the heat not coming out of the vents but i still had no heat. The strange thing about the heat is that it will blow out hot when you first turn it on for about 20 seconds before it goes from hot to warm and then a minute later it goes to luke warm. Also when you turn the heat off or the fan speed all the way down then turn it back up the heat will blow hot again for 20 seconds. Both hoses going to the heater core are hot. I tried to burp the coolant system by removing the cap off the reservoir and letting the van run while squeezing the hose. I spent all winter last year without heat and I'd really like to figure this out for this winter so anybody who has any suggestions id really appreciate it!

is it possible that my by-pass of the vacuum line could cause this?

 

If I gather you can control the air flow as would be considered normal---Vents, Floor Defrost Mix and Full Defrost? If so the issue would seem to be in the blend door system. Can you control the outlet air flow by moving the dash mounted temperature control?

Since both heater core hoses are hot you don't seem to have a clogged or restricted heater core.

 

Did you check the hoses while the air coming out of the vents is cool/cold? It sounds like you have only a trickle of coolant through the core and its heat is quickly extracted when you operate the blower at higher speeds.

 

 

 

Since you do have full control of the air flow and the temperature control does seem to actuate the blend door properly I'll defer to ProjectSHO89's suggestion the heater core could be clogged. Has anyone ever used that Stop Leak gunk or something similar?

Because the entry and exit hoses are hot to the touch doesn't mean you're getting full coolant flow through the heater core. Repeat your feeling for heat test but when the air flow becomes cold feel the heater hoses again---that might be revealing. If the outlet line (one leading to the back of the engine) cools down considerably its a strong indication the heater core is restricted.

 

 

I keep going back to the thrermostat...

 

It could be the t'stat but an easy way to test actual coolant temperature is with engine at operating temperature stick a probe-type thermometer into the coolant recovery bottle. If you do this remove the pressure cap C-A-R-E-F-U-L-L-Y and S-L-O-W-L-Y!!! You can also use an infra-red thermometer aimed at the t'stat housing, the upper and lower radiator hoses and the intake coolant crossover tube to determine the coolant temperature. Also any OBD-II scanner that reads live data can report what the CHT sender is seeing too.

I hope this is nothing more than a simple fix like the t'stat--its not fun changing a heater core, been there done that.

 

I just checked mine, it's the blend door, the actuator is working fine, I guess I have to replace it and I'm pretty sure I'll have to remove the heater core to get to it. There is a guy on youtube with videos on how to do it. Your problem might be different but mine is definitely the blend door. I already ran a new vacuum line and the A/C works now but the heater is just blowing cold. I was thinking of taking the actuator off and putting epoxy on the end of the shaft and bolting it back on and let it set for a day until it hardens. What happens is the male shaft on the actuator splits the female coupling part that goes into the door when it spins. I am going to turn it all the way to cold first, take the actuator off, put jb weld or epoxy on the shaft then slide it into the door hole but will test it by sticking a stubby screwdriver or hex wrench in and see if I can turn it manually to see if there is enough to epoxy to.
If yours starts out hot I wonder if the actuator motor just isn't strong enough to hold it open or if it's just the female part that's stripped or cracked inside letting it close itself.

 

There's no need to use adhesive on any of the blend door parts----doing so pretty much ruins both so save some money and properly replace only those parts that have failed.

IF the blend door isn't moving properly using any sort of adhesive in an attempt to fix it will result in two parts needing replaced. Make double sure the actuator motor is moving properly in relation to the temperature controller---either of those plus that circuit itself could be at fault too.

IF the blend door needs replaced its accessed from inside the cabin, the outer part of the heater core/evaporator case is all you need to remove; 7 screws holding it to the mating half. Be advised there is a Philips screw that's damned near impossible to access if its never been removed previously. Check this image:

Screw AA is actually located up under here:



My solution removing that screw:



Removing the outer case does require a bit of yanking outward so it flexes just a bit, enough to clear several small obstructions---keep in mind the drain projection shouldn't be bent too much---it could snap off.

I've posted a few photos of associated parts for this operation here:Blend Door Photos