Thought I'd throw up a DIY on a common problem with the '99-'09 Saab 9-5.This is a collection of ideas I was given by members on another forum and my personal experienced.
Symptoms of a coolant/heater bypass valve going bad:
-Coolant leakage under the firewall
-Smell of burning coolant
-In some cases (like mine) a catastrophic leak that dumps the whole coolant tank
Very straightforward replacement that I completed on my '03 Arc in about 55 minutes. Total cost was about $40 for the valve from eEuroparts.com
Tools needed:
-Narrow tipped pliers
-A socket set with wrench
-Bungee cord
-bucket (to avoid coolant spillage all over your garage)
-Cutters of some sort
Procedure:
1. Place the bucket under the car under the valve.
2.Mark the top tube with a pen/marker so you know where it goes afterward
Attachment 4112
3. Undo the wire harness box
Attachment 4114
and use the bungee cord to pull it toward the front of the car so it's out of your way.
4. Clip the zip tie from the top hose and remove all of the silver hose clamps and undo the hose from the top of the valve
Attachment 4113
5. At this point the valve should slide upward out of a bracket that is attached to, I believe, the hoses behind the valve.
6. Slide the new valve into the bracket and reconnect everything. Be sure to put a new zip tie where the original one was or else the valve will flop around the may come out of the bracket.
I hope I didn't leave anything out, I did this repair awhile back. If I did, chime in!