DIY: Heater core replacement in BD/BG/BK

[Dead91silvia]

Time for the dash... :smt009 I'm sure I missed a few here, but you will get the point...

Top cover is tricky... It's better to damage the little cover then the dash. Use something flat to pull up, do not pry up as it will damage the dash pad...




Cover removed... 2 10mm bolts...




There is one of these on each side of the dash... 10mm bolts...


Remover steering column bolts... 2 12mm... (Also no pic, remove column shaft bolt on rack)


The dash should now be free.... Time to unplug a butt load of stuff!
Passenger Airbag needs to be unplugged... MAKE SURE THE BATTERY IS DISCONNECTED!!!!


A pile of plugs on driver side... Also the HVAC, Stereo, and other random things...


This is what you should have out....


I opted to have the HVAC unit still hooked to the car, or heater box...


Dash should be ready to be pulled... now time to remover the cross bar... 4 12mm nuts and bolts of driver side, 2 12mm nuts on passenger side. 2 10 mm nuts behind Airbag Control unit, 4 security bolts for ABCU...












Now for the hardest part! You think I'm joking huh.... Yeah, no joke getting the box off the fire wall is crazy hard! There are a few 10mm nuts and bolts that hold all the boxes to the fire wall. This is where I kinda gave up on pics and procedure. It is ether glued to the fire wall, of the fire wall insulation melts and holds the heater box to the wall. This makes it really hard. I left the AC box alone since I have no need to service it at this time and thats more money.


The glued stuff....


One split heater box...


And the new core... You remove the pipes from the core and reinstall...


Ok... So if you have really got this far, you can figure out how to put it back together. In truth, it goes back together much easier then it comes apart. If you have a Dealer installed alarm, know that you will be cutting a few hard wired wires. This is a big job and I worked on it for about 9 hours with only a short 30min brake.

This is a job that you can do, but at your own risk! Hope this helps someone...

[Patrick Olsen]

Excellent write-up. I just pulled mine out, and figured I would add a couple pics to fill in where you gave up on pics.

Now for the hardest part! You think I'm joking huh.... Yeah, no joke getting the box off the fire wall is crazy hard! There are a few 10mm nuts and bolts that hold all the boxes to the fire wall. This is where I kinda gave up on pics and procedure. It is ether glued to the fire wall, of the fire wall insulation melts and holds the heater box to the wall. This makes it really hard. I left the AC box alone since I have no need to service it at this time and thats more money.

After I drained the cooling system, I pulled the heater hoses off the hard lines at the firewall, and then I stuck a couple of vacuum caps backwards into the hard lines to seal them and keep any residual coolant from leaking out inside the car:


As you said, only 3 bolts/nuts hold the heater box in place, and there's a harness to unplug on the driver side:






Like you, I found the heater box did NOT want to pull away from the firewall. I was pulling and prying, but something seemed stuck. Kind of on a whim, I took a can of spray silicone lubricant (which is great for breaking loose things like old rubber exhaust hangers) and sprayed that on the hard lines and the firewall seals in the engine bay. Went back in the car, pulled on the heater box while rocking it back and forth a bit, and it came right out. So I think in my case what was holding the thing in place was the rubber firewall seals being stuck to the hard lines.



Edit: When I went to actually pull the heater box out of the way completely, I found that there is an additional harness to worry about, located lower on the heater box than the harness I showed before. In this case, the harness is mounted to the box, so you remove it by removing the phillips head screw in the 2nd picture: