After researching my vehicle symptoms I've come to the conclusion that I need to replace the heater core on my 02 Expedition. It has the dual cores and there is coolant leaking above the catalytic converters onto the heat shield apparently from the condensate tube. It reeks of antifreeze with climate control on and fogs the windshield. (Also found after getting started that coolant had been leaking into the passenger floorboard but I hadn't noticed it because of some things I had in the floorboard)

I've found some good info on how to pull the dash and replace the heater core:


My question is what else should I replace for good measure while I have the dash off? It's the 4.6 liter engine. Obviously I should inspect the blend door and possibly replace. Does anyone else have any suggestions for anything else I should do while I have the dash off, or any tips on replacing the heater core? I'm going to take the plunge this weekend.

Thanks!

 

Well I got the old heater core out today and I'll put the new one in tomorrow. And yes, as suspected by my symptoms the core was the problem. The video i posted was exactly right for my 2002 Expedition XLT with 4.6 liter engine. There's a couple issues that I'd like to point out that would have made the job easier if I would have known.

1. Set your temperature dial to about 9 o'clock or so with the key turned on. This will move the blend door and will make removal of the blend door assembly and heater core easier.

2. If you have electric seats on the drivers side don't disconnect the battery until after you remove the first 2 bolts in the video, the bolts from the rear console. After they're removed move the drivers seat all the way back and then you can disconnect the battery. This will allow plenty of room to work inside and space for the steering column to come down. Also, I would recommend removing both battery terminals instead of just the negative one.

2. The drivers side of the dash will not come out far at all with this method. The large wiring bundle that comes through the firewall is very tight and won't allow the drivers side to move much at all, but that's ok, it doesnt have to. You can lift it and pull it back about a couple inches or so, that's it. Once you get all the wiring on the passenger side disconnected the passenger side of the dash will pull out enough to be able to access everything you need to. It's tight and not particularly comfortable but you can reach everything you need to get the core swapped with just the foot or so of space you can get from pulling the passenger side forward. If you have to move the dash yourself I'd lift up and pull the driver's side forward what little bit you can first, the lift up and pull the passengers side forward and disconnect the wiring harnesses and antennae/wiring push pin things and pull the dash forward some more.

3. The video doesn't show all the screws that hold the plenum/heater core cover in place. There are around 12 I believe. There are 2 or 3 on the very back that are difficult to find but rest assured if you can't move the whole cover up and seperate it from the bottom all the way around fairly easily then you've missed a screw or 2. You will need a long extension for your ratchet to reach a couple of them.

4. The video doesn't show removing the small vent tube on the top ride side of the dash, above where the passenger air bag was. There is one screw that holds it in and it is easy to pull out. It is very difficult or impossible to remove the plenum cover otherwise. Also, make sure you have the vacuum line that runs across the top of the plenum cover moved out of the way.

5. Accessing the heater hoses from the engine compartment is a real bitch. I went to walmart and got a short one handed hacksaw for 3 bucks and cut the 2 heater core pipes near the firewall on the inside of the vehicle and pulled them out through the engine compartment. This was a lot easier than trying to disconnect the connectors from the engine compartment. You can buy replacement quick connector ends in the accessories section at the parts store. Instead of splicing them into my lines I will take the plastic clips and o-rings out of the new ends and use them in the existing hose ends most likely.

6. Definitely inspect your blend door where it connects to the actuator while you have everything off. Mine was fine but I'm going to replace it anyway. The parts store down the street has a beefed up replacement door with a metal sleeve for 22 bucks. I highly recommend swapping them out while you have the dash off.

The blend door frame will not come up unless you have the heater core pulled up some already. The bottom of the frame is under the heater core so don't get rough and crack the frame trying to get it out like someone I know did (HVAC metal tape repair)


7. The heater core I bought only came with enough weatherstripping to wrap the bottom and sides. I figure having the stripping on the top like the original one I pulled out is unnecessary but I'll probably try to get some more at the parts store for the top anyway.

Other than that the video covers pretty much everything. Yes, you can remove the core without pulling the dash completely out. Also, I put bolts into ziplock bags and numbered and labeled the bags by each step as I went. No leftover screws this way.

 

Wow... if I'd have known how much of a pain in the *** this was going to be I would have paid someone to do it, without a doubt. Getting the new core in wasn't too big of a deal, though I would recommend anyone doing this to go ahead and disconnect everthing from the driver's side and fully remove the dashboard. I have a feeling that there is actually minimal time saved by not removing the whole dash, and it would definitely make putting the new core and blend door assembly in a lot easier. I had a helluva time getting the blend door assembly back together and I'm not sure if it was actually totally in place like it should be, but I said to hell with it and put it back together any way after hooking the battery back up and the wiring harnesses on the passenger side and testing to see if the blend door would move. It did work fine, except I don't think it would fully close all the way on cold. It didn't look like anything was blocking it though. Apparently I ended up with the wrong quick connectors for the core also because after much frustration and cussing I couldn't get them on. I ordered some different ones at the parts store and they'll be in tomorrow. This job is beyond ridiculous and if I knew how much of a pain it was going to be I'd definitely have paid up to 400 dollars or so to have someone else do it. Automobile engineers are freaking douchebags.

 

I got the right connectors at Oreilly and the quick connectors slipped right on to the heater core. Fired it up and there appears to be no leaks. Refilled and burped the degas bottle and everything seems to be good to go.

Here's a 3 part video series that is also helpful:

 

Pretty sure you saved more than $400.

I was quoted $1000+ for a heater core replacement over two years ago.

 

Yeah it would have cost about that in most places. I found a mechanic who works for a shop who lets him do side jobs and he said he'd do it for about $400. It was a learning experience overall all and at least I know a lot more about my vehicle now. Now that it's over with I guess I'm glad I did it myself lol.

The blend door wasn't fully closing on cool but I put it back together anyway. Not sure if it was binding up or what but I was frustrated and put it back together anyway. I'll see how it does with the a/c in the summer.

Getting the dash off is pretty simple, it just takes some time, but changing the core and blend door was a major headache. I could do it a lot faster now if I had to do it again.