When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have limited knowledge of automotive A/C and heating systems but I do all the work on our BMW so I’m not afraid to wrench. Our E250 is not producing any heat. Is there an order of things to start checking/testing first, second, third, etc? Been reading about the blend door on the interwebs and fear that might be it, but I don’t know where to start diagnosing things. I assume I’m going to start at the climate control panel and work my way deeper from there?
First thing to check is coolant level. Believe it or not that's sometimes been overlooked when this sort of issue arises. Start engine, watch temp gauge climb until it gets close to operating temp, about 190. Look for the coolant level in the reservoir to drop as the t'stat opens---or doesn't. If it drops significantly there might not be enough circulating to fill the heater core.
We need to know if you have fan speed? Or is this just no heat at all?
If yes to above then its time to check the inlet side of the heater core---it'll be the hose coming off the front part of the engine. Once at operating temp does the hose feel warm? If it does then check the outlet hose for the same---if not similarly warm as the inlet then the heater core is blocked or plugged.
If its plugged I hope you're up for at least a full days challenge of changing this part---been there, done that and its NOT easy at all!
Also when posing such a question give us the engine size---I'm assuming this is a 5.4.
My bad. I edited my original post to add that it is indeed the 5.4.
Coolant level looks good. Seems to drop about 1cm when the thermostat opens. All fan speeds work fine. That's all I got to today since I was at work. I'll post back after I check the core in & out.
Did a little more poking around today. Both the core inlet and outlet hoses are warm, assuming I'm checking the right hoses. The hoses I'm talking about are high up on the firewall kind of in the area behind the tranny dipstick. Those are the only two I could find with quick disconnects. But, it looks like they both head from the firewall toward the rear of the motor.
Remove the outer half of the air cleaner canister including the silly snorkel---set them aside and look at the top of the intake manifold for this hose:
This should lead only to one tube of the heater core, inlet. Another line out of the heater core will be located close, same aluminum tube (but different size)---that should lead to the back side of the engine.
Mine definitely looks different than that. I'll post pics when I get home from work. Maybe mine is set up different because it has factory plumbing for rear A/C?
edit: I pulled the doghouse back a bit and had a peek. Looks like I've got a hose coming off the back of the motor that tees off - one hose heads toward the firewall and another heads under the floor out back. No pics of that yet - it was too dark.
Also checked all the servos that I could easily locate. I assume these have nothing to do with heat but the two under the panel on top of the dash, and the one you can see behind, and to the right, of the heater core enclosure all seem to be functional.
It wasn't mentioned earlier on there is rear heat & A/C in your van---useful info.
My own experience with a second heater coil in the coolant system greatly affects heat output at both coils. It's tough to know what "warm" means--readings with an IR thermometer would be a bit more helpful.
I'd check temps of the coolant lines leading to the rear coil, both nearest the engine then at the connections to the rear coil itself. If nothing else where the coolant lines run through the floor from underneath the van.
Is there full blower control over both front and rear units? Does the outgoing airflow temp change at all when the dash-mounted temp control is moved?
It wasn't mentioned earlier on there is rear heat & A/C in your van---useful info.
My own experience with a second heater coil in the coolant system greatly affects heat output at both coils. It's tough to know what "warm" means--readings with an IR thermometer would be a bit more helpful.
I'd check temps of the coolant lines leading to the rear coil, both nearest the engine then at the connections to the rear coil itself. If nothing else where the coolant lines run through the floor from underneath the van.
Is there full blower control over both front and rear units? Does the outgoing airflow temp change at all when the dash-mounted temp control is moved?
Yeah, I'm just full of useful info Never thought about that until I saw the lines running toward the rear of the motor. Then I remembered seeing the extra plumbing when I took the doghouse out for the first time a few months ago when I bought this thing.
Here's some more LOL, there is no rear heater coil or A/C. The van was ordered with the plumbing for all that but Sportsmobile put a separate third party A/C unit in the back - no rear heat, furnace, etc. The rear A/C doesn't work either, but that's a thread for another forum. Anyway, all the lines are just capped off. Actually the refrigerant lines are capped off and the coolant line just has a "U" hose.
If it stops raining (not likely), I'll check today to see if the "U" hose under the van gets warm. If it keeps raining (highly likely), I'll at least check the hoses behind the doghouse. No IR therm, but I'll do my best.
What part of the van is this photo? Can you zoom out a bit, show me something with a slightly larger view?
Right off the bat I'd suggest the U tube be located as close to the engine as possible. Coolant now flows through those lines which acts like a huge radiator, partially due that length and the fact there's probably not much if any insulation on them. This saps BTU's out of the coolant which may be an issue.
Little too rainy to run out and get another pic right now. That's an old pic from my gallery on that other forum This is underneath the van on the driver's side right behind the driver's seat. So, not too far from the rear of the motor.
Here’s what the hoses look like behind the doghouse on the passenger side. Looks like coolant would come out at the arrow? The two hoses heading toward the bottom left of the photo are the ones that lead out back for auxiliary ac/heat. Both of these hoses are definitely hot at operating temperature.
Here’s the rear lines exiting the cab area…
And here’s a better shot of the rear connections and “U” tube. The "U" is also definitely hot at operating temp.
No Heat - ’97 E250
Never thought about that until I saw the lines running toward the rear of the motor. Then I remembered seeing the extra plumbing when I took the doghouse out for the first time a few months ago when I bought this thing.
This is underneath the van on the driver's side right behind the driver's seat. So, not too far from the rear of the motor.
