I also replacement my heater core this weekend. Definitely a big job! I think it took me a little over 10h but overall it wasn't as frustrating as I feared it might be. Every youtube example is slightly different it seems.
My approach summary:
- partially drained the cooling system from the radiator petcock.
- Evacuated the AC and pulled those lines from the engine bay. (I'm not certain this was necessary but I'm also surprised to hear that
@Big Al (post above) was able to pull the HVAC box back far enough to fully access the heater core while the AC lines were still attached. That did not seem possible to me but aparrently there is a way...)
- Left the steering wheel and airbags in place. I did loosed the 2 vertical black starnuts which hold the wheel-adjustment-limiting-bracket to the column, just to let the wheel drop an extra inch. Those same bolts also prohibit the plastic dash from moving forward enough.
- The only electrical connection I touched at all was the passenger side dash tweeter/speaker.
- I took the dash instrument panel out (4 screws) but left it connected electrically.
- Didn't touch any pneumatic/vacuum devices/lines other than the blend actuator line which sneeks through the firewall alongside the AC lines.
- Used a ratchet strap from the rear passenger. Didn't need to go crazy on it.
- Ultimately I had enough clearance to easily reach behind and pull the core straight out without doing anything weird. I could even look down into the mounting slot and see the coolant down there to clean it up.
- I haven't tested my old core yet but it visually looks to be in a terrible state with old and new glycol stuck all over it.
- New core from Four Seasons was $42CAD+30CAD shipping to BC on RockAuto.
- Refilled the cooling system and immediately bled it from the hex port near the upper radiator
- Fortunately, and somewhat amazingly, everything works perfectly now. Heat is better than ever.
Tips:
- there are two bolts behind the radio/AC control panel which firmly connect the dash to the HVAC box. I found that separating the dash from the chassis and firewall was one thing, but separating the HVAC box from the dash was a separate thing. You need both to get ample clearance.
- dont try to skimp on removing plastic panels.
- definitely get yourself one of those reverse-pliar sets which pull apart when sqeezed. They are made for removing auto panel pressfits and work like a charm, dramatically reducing the chance of things breaking. Cheap on Amazon.
- have a long extension piece to your 1/4" ratchet with a deep 10mm socket. Some of those were hard or impossible to get a 1/2" socket set on due to the larger diameter.
- a couple of the 10mm bolts require a deep socket. None of the 13mm bolts did.
- Most of the plastic panel screws are the same, 7mm with a phillips #2 inside.
- being in a heated garage really helps the compliance (and non breakability) of the interior plastic panels.
- when you go to push the whole dash+box back into place, dont forget about the AC condensate spout! Its that 3" bent rubber hose which sticks through the firewall down low.
- If you have any known naggling dash area creaking or vibrating offroad, now is the time apply some lubrication and electrical tape.
- If anyone sends me a DM with further questions I'll try my best to help.
Mechanic cost?
- My trusted mechanic quoted me $1500 but couldn't do it until early Feb. They were also very unexcited about the task.
- The second most reputable autoshop in town quoted me $1900 but when asked to commit retracted entirely, saying its too risky of a job for them.
- A lesser trusted mechanic in town declined to offer any price, saying its a terrible and uncontrollable job.
- The Crystler dealership in town quoted $2300 "If everything goes absolutely perfect, which it wont." And could do in early January.
- Nuts. Just nuts! I'm an idiot and still figured it out in reasonable timeframe.
