So I replaced it today. I have been procrastinating about this for more than 3 years. Yes you have to remove the entire dash and discharge the AC system and take part of the AC system apart at the fire wall in the engine compartment and drop the steering column. And remove the center console. But the whole thing start to finish only took 4 hours.
Reading other forums you would think that hell will freeze over, cats will be chasing dogs and it will take an entire weekend to do this job.
Kind of surprised me actually. I was also surprised to open the heater core I got from autozone and found it to be an exact match to OE one that was in the car. Most aftermarket units have about half the number of fins.
Everything seems to work after I got it back together and I even solved the weirdness that was going on with the climate control (loose vacuum line connection where the two bundles of vacuum lines connect)
Oh no left over fasteners and not one cut or skinned knuckle.
I think I am going to buy a lottery ticket tonight.
My 97 Jetta also needs a heater core...
Same thing, step 1: remove dash...
dean1484 wrote:
I think I am going to buy a lottery ticket tonight.
You might want to buy more than one. 
The last HC I did that dash removal was required took 12 hours. The first thing the factory installed in the car was the HC Everything, and I do mean EVERYTHING on the firewall was bolted on top of it. 
On the other hand, the E250 I did the other day took 45 minutes not counting the 3 trips to Autohell to get the correct part.
The old joke for a lot of cars is they start out on the assembly line as a heater core, and then everything is built around it. 
stuart in mn wrote:
The old joke for a lot of cars is they start out on the assembly line as a heater core, and then everything is built around it.
Which is just one of many reasons I absolutely hate automotive engineers and designers.
Its getting pretty rare to not have to pull the dash for a heater core change. On the upside, modern cars are assembled with the dash as an assembly, so its usually pretty easy, as long as you follow the instructions. The part that galls me is the AC disconnect.
Old Mercedes, though- trying to bend the bits of timber trim out from everywhere while taking every single individual part out of the car....and we changed a fan motor in an Acura Legend one day. Makes a Volvo 240 seem positively intelligent.
The worst heater core I have ever done was in My MB 190E 2.6. You have to strip it down to the firewall completely.
At least with the Mustang you don't have to disconnect everything. There is enough slack in the wiring harness on the drivers side that you can pivot the passenger side out var enough to get the job done.
A tip in the mustang's. If you are installing the dash by your self. There is a large stud on the driver side A pillar that the dash mounts to. Get the dash on the stud and put the bolt on hand tight. Since this side is only pulled back 6-7 inches it is very easy to get this back together by just grabbing the gauge pod and lifting it up and forward while standing next to the car with the door open. Then you can just pivot the dash back in place form the passenger side. Put a screw in to the top of the dash in the defrost vent on the passenger side and the dash is now held in place and you can get all the other nuts and bolts in with ease. I am betting that this is probably the biggest problem that most people have as the dash assembly is quite heavy and trying to get it back in place by lifting it as a unit from inside the car would be very difficult.
