Heater Core repair

On the 10/11 show, a caller with a Honda Civic called with the problem of a leaking heater core, and you recommended that he replace it himself.
I recently had that problem with my 1998 Taurus, the first major problem that I have ever had with that car, by the way. When I read in Chiltons what
was required to replace the core (similar to what the caller described, plus disconnecting the air conditioner), I took it to my favorite independent mechanic. He didn’t even want the job. He recommended that I get a high quality and relatively expensive stop-leak that he recommended and try that. I did, and it seemed to work. I say seemed, because that was last Spring. The heater core is disconnected until the heat is turned on. I tried it several times, and the leak, which used to be ferocious, is gone. But I won’t have a chance to really try it out until it gets cold, which here in South Florida will be in mid-January. But it sure is an easier fix, which the caller should try.

On many cars replacing the heater core is a tedious nightmare. We had a Ford Granada, and the whole dash had to be taken down to do the job. My trusted mechanic told me he would not do it again at any price.

Many cars seem to have been built the car around the heater core.

Luckily I had 2 big Chevies, a 1984 and a 1988 that had a more sensible design, and the job only cost a couple of hundred dollars.

I’ve never replaced a heater core in a Honda Civic. Maybe it is an easier job…like the old designed cars vs my Dakota and your Taurus.

My Dakota Pick-up truck requires that the entire dash be pulled away from the firewall to even access the Heating/cooling unit. Once this is unbolted and pulled away…can you access the AC core…and then you can finally get to the heater core to remove it.
The need to have to have the AC evacuated, refilled when the job is over, and then having the AC tested for leaks…is backwards to me. That may cost you $200 of unneeded expense if the two were swapped and the heater core was the one in front.

This is a mistake in the design as far as I’m concerned. The heater core is one part that is a common repair enough that it should not be a job this involved. But many cars today have this same design.

I’m sure there are many more heater cores that need to be replaced, compared to the AC core.
If the AC core was behind the heater core, it would make much more sense. If the Ac core needed to be replaced, you would only be throwing away $20 of coolant having to remove the heater core first.

I have had plugged heater cores in two of my vehicles, and it made more sense to jury rig a pump and hoses to flush the heater core while not removing a thing except the two heater hoses. I pump a mix of 50/50 water and Lime away thru for about 20 mniutes, then reverse the direction of flow for another 20 minutes, and flush the core with fresh water for 5 minutes.
I’ve also done this flush on about 5-6 other cars with great results.


RE: 1998 Ford Taurus:
If you Google ‘‘Youtube Auto Taurus Heater core short cut’’, you’ll find it can be done in ~2 hours. Some minor innocuous cutting is required.

I had an air conditioned Ford Maverick and had to have the heater core replaced. The job involved moving the evaporator to get to the heater core and was very labor intensive. On the other hand, I had to replace the heater core on my 1978 Oldsmobile Cutlass Salon and it was rather simple–the heater core was in a box under the hood.
Before I would have the dash torn apart, I would investigate installing the old fashioned recirculating heater in a box that mounts under the dashboard the way many cars were heated in the 1940s and I would mount a fan on the dashboard to defrost the windshield.

@Yosemite, I’ve done a few Taurus heater cores with CLR as you described. It’s a quick and easy fix for a plugged heater core, but a leaky one is another matter. A @JoeMario stated above, there is an easier way to pull a Taurus dash slightly away in order to change the heater core. Check you tube.

Sorry @MG Mcanick, I got so involved explaining the difficulties, it slipped my mind that it was a leaker. I have a good memory…it’s just short!!!