Read everything before you start!I replaced my heater core in February of 1998. I didn't replace the blower motor at the same time,but should have. I had to do most of this over again in May of 1999. Tasks marked with a * can be skipped for the blower motor. Tasks marked with a # can be skipped for the heater core.
I purchased my new heater core kit from Lititz Auto Service in Lititz, Pennsylvania for $125 (www.saablititzauto.com, 1-717-626-5264). Kevin and Tim are very knowledgeable and nice. They will provide free advice if you ask.
I purchased my replacement blower motor from Import Parts Specialists (www.importpartsspec.com) for about $95. This was just the motor, and did not include the fan or the housing.
Special tools needed: A very long needle nose pliers or hemostats. Otherwise, the normal assortment of metrics sockets, Torx drivers, pliers, screwdrivers and so forth should work.
What NOT to do: No need to remove the bonnet (hood), or disconnect the battery. It's probably wise to disconnect the battery from a safety standpoint, but make sure you have your radio code if you do this. I didn't disconnect it and didn't hurt anything.
For additional info on changing your heater core, you may want to visit Brian Kennedy's site. He has a nice commentary on my procedure, combined with some great photos. (Brian's heater core site)
1. Mark the positions of the wiper arms with masking tape or a marker for later assembly. Lift up the plastic covers and remove the nuts holding on the wiper arms. Remove the wiper arms and the large rubber grommet (for lack of a better word) under each wiper. My passenger side wiper was very stubborn, and took a lot of careful prying to get it off.
2. Remove the three grills next to the fire wall (5 clips and 4 Torx screws).
3. Remove two bolts holding in the fake firewall (or bulkhead). Remove the bulkhead. Again, mine was very stubborn, and took a lot of yanking and prying, but eventually broke loose. Just don't force anything.
4. "Carefully remove the plastic drainage molding from just below the windscreen." -Haynes. There are a bunch of little plastic retaining stubs that need to be pried out. Then lift up the rubber windshield molding and pull out the plastic molding.
Again, not difficult, but be careful.5. Remove the wiper motor. Carefully mark the position of the rotating arm so that it can be reconnected in the exact same place. There is a circlip on top of the center bolt that needs to be removed, and then the center bolt and arm can be removed. Then remove the three remaining bolts. Disconnect the two wiper motor electrical connectors. These were very stubborn on mine, and I broke off both little retaining clips.
6. Haynes says to unbolt and move the electronic control unit (ECU) at this time. I didn't and don't see any reason to do so.
*7. Drain the radiator. Sounds easy but it's not. You have to first remove a plastic cover underneath the radiator. Loosen two bolts (but don't remove) near the front of the car, and then pry out the back end of the plastic cover. The whole thing slides out. The drain plug is on the passenger side, and is made of plastic with a single blade sticking down. Don't force it! I just used a pliers and unscrewed it.
*8. Disconnect the plastic matrix coolant supply "manifold". This thing plugs into the heater core and has a plastic release clip in the middle that must be pushed in (towards the passenger side). Again, this may be stubborn, but keep working at it and eventually it will release, and the hoses with the manifold will pull off (out).
*9. Label both heater hoses carefully, and remove them from the matrix manifold (2 hose clamps). (Note: no need to do this if you buy an original Saab heater core. My after market one did not require the manifold.)
10. Remove the throttle housing. Three bolts, plus the throttle linkage and cruise control linkage and possibly some vacuum hoses. You also need to remove the big tube from the intercooler (turbo only). Just move the throttle housing to the side.
11. Unbolt the front bolt for the throttle dashpot, loosen the back bolt, and rotate the dashpot up out of the way. Re-tighten the rear bolt. You will need every mm of space!
12. Disconnect the vacuum line for the cruise control, which is near where the heater matrix was, and move it out of the way. Unbolt the cruise control system vacuum pump (two Torx screws, and move it to one side.
13. Unbolt the evaporator housing (on passenger side). Two bolts, one in front and one in rear. Free the rigid refrigerant pipes. I unbolted the bracket on the top of the wheel well to give me more movement. Move the evaporator to the right (passenger side) as far as you can. It doesn't move much, but you'll need to lift and yank on it a bit later.
14. Disconnect the inner control cable for the temperature control valve on the passenger side of the blower motor. This is where you use the very long needle nose pliers. It's a little round clip, it's hard to get to, and a bugger to get off! You may ruin it, but you should be able to pick up replacements at the hardware store for pennies (so make sure you do this when the hardware store is open!). But just be careful not to break the rod itself. Again, patience is a virtue with this one.
15. Disconnect the two electrical connectors for the blower motor (don't mix them up with the wiper motor!). Again, these were very stubborn to pry apart. Be patient.
16. There is a metal slot bolted the firewall with four bolts than the false bulkhead sits in on the driver's side. You can try getting the blower out without removing this, but I couldn't. Just sliding this away from the blower motor should give you the couple extra centimeters you may need.
17. There are two plastic clips integral to the fire wall which hold on the blower motor. I used two very long handled screwdrivers to pry the clips out. These must be moved out in order to get the @$#*($ blower motor out. Once you break the motor free from the firewall, you must wiggle, turn and contort the blower and your body in order to get it out. A helping hand to move the evaporator up and away would be nice here (I didn't have one). I probably wrestled with the #^%%!& blower motor for 15 minutes before I got the sucker out.
#18. If you are replacing the blower motor, you must separate the housing to gain access. There are four platic clips that need to be removed. There is also a plastic piece that runs the length of the vent area that snaps off. There is one Torx screw recessed in the middle of the housing that also needs to be removed. After this, the housing should separate with careful prying.
#19. Next you will need to remove the motor from the housing. There is one phillips screw on the backside of the motor that must be removed. My motor did not want to come out. I used a larger phillips screwdriver placed in the opening where the screw was, and while a someone held the housing upside down, I tapped with a small hammer. Eventually, it broke loose and came out of the housing. You will also have to remove the plastic clip from the ends of the green and black wires, and work the wires throught the housing, including the strain relief boot. Be careful to not drop it when it eventually falls out!
#20. You must now remove the fan from the old motor. It is simply pressed on to a splined shaft. I used a small drift, and again had a helper support the fan while I tapped on the motor shaft. A few taps, and it broke loose and was easily removed from the fan.
#21. Reinstall the new fan into the housing making sure the screw hole lines up properly. You may have to tap it in. Reinstall the fan onto the motor, again tapping gently with a hammer. Connect the two halves of the housing, and reattach all clips (careful, I broke one). Replace the Torx screw and the front plastic piece on the front.
*22. You are now (nearly) home free! The heater core should be easily visible. It slides straight out from it's little compartment. Again, you will need to hold the evaporator up in the air a ways for clearance. It took me about two hours to get to this point (not that it's a race or anything).
23. I then vacuumed out the whole cavity with my shop vacuum. I first felt around for any pieces that may have dropped in there that might come in handy! There were a lot of leaves and debris in there.
*24. My replacement heater core did not require the little matrix manifold thing, but came with short hoses that you must splice into the existing hoses (that's why you marked them earlier!). It's not that bad, but you want to be very careful how you orient the hose clamps so that you can tighten/remove them in the future. You may want to connect the hoses before inserting the new core. I didn't and it was tight clearance putting on the new hoses (that's why Saab uses the manifold thingy I guess.)
25. Next put the blower motor back in. Did you remember exactly how it came out? I didn't, and wrestled another 30 to 40 minutes trying to get the sob back in. Again, don't force it. I had to lift the evaporator way up high in order to get it back in the way it needs to go. Once it's in, snap it back onto the clips. (I broke one off when I removed it, so I only had one to snap back on. Seems to work fine like this, and there's no way I could have replaced the broken clip without replacing the car!)
26. Reattach the heater control cable to the temperature control value. Put the little stinking clip back on with your long needle nose. This is really fun.
27. Refit everything else you removed. *You may want to start the car back up after re-installing the throttle housing and dash pot and refilling the radiator, and make sure your new heater works and there are no leaks. I did this, and my car proceeded to overheat, and no heat from the heater! Frustrated, I called it a day, and started in on it again the next morning (Sunday). It turns out I think I just had air in the system and needed to bleed it off, and add a little more antifreeze. This was the only real glitch I ran into.
28. Re-install all of the trim pieces and everything else. The plastic windshield molding was a little tough, but start at the middle work your way around to the corners. This is why they probably suggest removing the hood, but it's really not worth it. For my broken tabs on the electrical connectors, I just used cable ties to hold the connectors together.
29. You may want to replace the filter inside the evaporator while you're at it. Mine was grotesque. There's a little panel that unsnaps and flips up. You can then pull the filter straight out. It's about 12" x 9". Saab wants about $30 for a new one. This thing actually comes apart, so I split it, and made a new filter out of a furnace filter for $.49. I used electrical tape to help hold the two halves together.
Summary
Most people recommend to replace the blower motor at the same time. Mine was working fine and made no noises, so I left it and ended up up replacing it 15 months later. You may want to consider doing this, otherwise, you have to do the whole job over again when the blower goes out. I've heard you can just put new brushes in the motor, but if you plan on keeping the car, I would go with a new motor.All told, I probably spent between five and six hours to replace the heater core. My local Saab dealer wanted between $500 and $600 to do this. I did just the blower motor in under four hours. I did this for the price of the core and fan and my time. But if you're mechanically inclined and have at least a whole weekend to work on it, you should be able to pull it off. I would also try to enlist the help of someone who is car knowledgeable, if possible.
Commentary
Everyone raves about Saab engineering, but I'm definitely not impressed with the design of the heater core and it's location. If they are going to bury it where they did, they should have at least made it out of stainless steel so that it last 20 years or more. As it turns out, this sounds like a pretty common problem, and they only last 80 - 100k on average..