Background
- Ford (Mazda?) engineers buried the Escort heater core under the dashboard, making replacement a time- and labor-intensive process
- Engine coolant heated to ~82 C (~180 F) flows through the heater core, warming the air blowing into the cabin
- I paid a mechanic at The Car Czar in Citrus Heights $500 to swap out the heater core in mid-2007...they seemed to do a poor job:
- cracked the dash in multiple places...probably inevitable, but they did not even mention it
- messed up the heater control cables so I have to throw the control really far to the left to get vented air into the cabin
- while taking apart the dash, I think i found a few things which look a bit odd, as well, like a vacuum hose not plugged in near the center console
- Our car overheated at least two times this summer: (1) when the radiator fan died--we noticed boiling coolant exiting the coolant overflow reservoir and ended up towing the car home; and (2) when two fan relays failed during an evening drive to Berkeley--no coolant exiting the overflow reservoir, but very audible noise of boiling coolant in the overflow reservoir
- After these repairs, we noticed our car losing coolant at an alarming rate, re-filling the reservoir every two weeks or so
- A local mechanic diagnosed the problem as a heater core leak and helpfully bypassed the heater core for us
- The mechanic estimated an ~$800 repair bill to replace the heater core: at least five hours of labor plus parts
- Motivation to fix myself: saving money, cold of fall/winter approaching
- This represents the most complicated auto repair I have undertaken
Preparation
- I spent a lot of time reading through the FEOA forums, watching videos, taking notes, figuring out the trickiest parts, asking questions--I did not want to jump in and get stuck
- I annotated RichPin06a's YouTube video as a guide multiple times...took notes, printed them, and used as a guide while in the car
- I started late in the day--not the wisest decision, in retrospect, but I felt impatient to start ; o )
- I initially took Trencher's advice and tried to remove the dash as a whole...then I lost heart as it got late, so I fell back on annotations from RichPin06a's video
- Motorcraft heater core (part #HC-8) - ~$50 from Rock Auto (link)
- S & G Upholstery Clip Removal Tool (also known as a panel remover) - O'Reilly Auto Parts (link)
- T20 Torx 3/8" socket (center defroster bezel screw)
- 3/8" universal joint socket (center defroster bezel screw) - AutoZone (link)
- 6" socket extension
- 7mm, 8mm, 10mm, 12mm sockets (assorted bolts)
- 18mm wrench (hood latch release nut)
- 10 mm x 12 mm metric double flex head flare nut wrench (dash bolts under windshield) - AutoZone (link)
- Generic LED work light
- Generic extension cord
- Needle nose pliers
- Box cutter
- Duct tape (tape screws/bolts to pieces they came from)
- Mechanix Wear "The Original" gloves (saves my hands from trauma) - AutoZone (link)
- Generic battery cable puller
- Sharpie permanent marker (mark the HVAC cables)
- Old, thick towel (lay equipment on)
- Zip ties (tie back speedometer cable to battery cage, and so forth)
- Written annotated instructions from RichPin06a's YouTube video
- Tin snips (optional; used to cut one wire ... see below)
- Worked in my driveway from ~4:00-7:45 p.m., at which time I stopped, on account of darkness
- I decided to tackle the three dash bolts under the defroster bezel as soon as possible, to see whether I had the right tools
- It turns out I did not--the 3/8" universal joint socket I had, combined with the 3/8"-to-1/4" converter socket, plus the 10mm socket, did not fit.
- After a bit of playing, I could see that a 1/4" universal joint socket plus the 10mm socket also would not fit
- I restored the speedometer cable and negative battery cable and drove to a local parts store
- After showing an attendant the location of the bolt, he recommended the 10 mm x 12 mm metric double flex head flare nut wrench...a quick check showed it as a workable, albeit tedious solution
- Total time away from repairs: ~15-20 minutes
- Ran into a snag with the steering wheel shroud cover...missed one of the screws but it all came apart with nothing worse than a few scrapes
- I found the three 10mm dash bolts on each side of the dash tightened too tight and slightly stripped.
- I think I stripped my 10mm socket, so I switched over to a 3/8" socket
- This worked for a few bolts, until I think I stripped that one too...
- I finally ended up using the next size down SAE socket, which just fit onto the 10mm bolt...that finally worked to loosen the last bolt
- I missed a connector on the passenger side
- About ten years ago, I swapped out the stock bumper and added a Ford Escort GT bumper, which supports fog lights.
- As a part of this swap, I investigated the stock GT fog lamp wiring and mirrored the wiring configuration in my LX, running a wire through the passenger sidewall and across to the driver-side fog-light switch
- Unfortunately, I soldered the fog lamp wiring in such a way which prevented me from easily removing the dash
- I simply snipped the wire and will re-solder as part of the second half
- I think one of the driver-side dash bolts may have dropped into the side...cannot remember
- Darkness increases the difficulty of everything...so does sitting in stressful positions
- When I pulled out the HVAC Outlet Duct Extension Center (Motorcraft part #18C505), I saw it had a light layer of coolant - yuck
- The inside of the heater box (HVAC Heater Assembly, Motorcraft part #18478) was coated with white residue--when coolant boils off, it typically produces white smoke
- Pulled out the heater core, sans one outlet tube--I think my mechanic broke it off, which might explain the source of the leak, if it had weakened the outlet tube
- The foam looked a bit gross, but reused it as best as I could on the new heater core
- Reinserted the heater core into the heater box
- Decided this represented a good stopping point
- Dragged all the parts into the garage and locked the rest in the car
Next steps
- If possible, I prefer to replace the stripped dash bolts...probably need special bolts to withstand proper torque...probably something to do later.
- Purchase replacement 10mm and 3/8" sockets
- Fix HVAC heater control cables so they work as intended
- Re-solder cut wire...investigate way to resolder as part of the fog-light switch wiring harness
- Take my time and ensure everything goes back together right
- Probably will take a good part of Monday and Tuesday night
- Investigate why one of the blower motor's contacts in the wiring harness connector seems corroded...something to mention to the mechanic
- Zip-tie under-the-hood light to the hood
- Replace air filter
- Clean seats and carpets
Celebrated with a Ace Pumpkin Cider.
