Solenoid valve, heat exchanger (heater bypass valve) - Saab 9-5 WIS

[SaabWorld]

This is also known as the heater/coolant bypass valve. These instructions are for the 2005 Saab 9-5 but should be the same for all model years.

Febi: http://www.eeuroparts.com/Parts/59569/Heater-Bypass-Valve-90566947F/
Saab OEM: http://www.eeuroparts.com/Parts/7079/Heater-Bypass-Valve-90566947/

Saab part number: 90566947




To remove

The solenoid valve is located in front of the bulkhead above the water shut-off valve.

1. Open the expansion tank cap and release any overpressure. Refit the cap.

2. Place a container under the car.

3. Pinch the coolant hoses with 30 07 739 Hose pinch-off pliers.



4. Disconnect the vacuum hoses from the valve.

Note
Check that the vacuum hoses are free from cracks and leaks.

5. Unplug the connector from the solenoid valve.

6. Remove the cable tie holding together the solenoid valve and the cables.

7. Remove the hose clips from the solenoid valve.



8. Take out the water shut-off valve with the solenoid valve.

9. Drill out the rivets to the solenoid valve.

10. Change the solenoid valve.

To fit

1. Replace the rivets with screws and nuts.



2. Lubricate the hose connections on the water shut-off valve with soap and water.

3. Insert the water shut-off valve and the solenoid valve.

4. Plug in the connector.



5. Fit the coolant hoses and hose clamps.

6. Fit the vacuum hoses to the valve.

7. Remove the pinch-off pliers.

8. Fit cable ties around the solenoid valve and cables.

9. Open the expansion tank and top up with coolant to max, see Bleeding the cooling system.

10. Test pressurize the cooling system to check for leaks using 30 05 477 Cooling system tester.

[J-Rod]

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



3. Undo the wire harness box



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



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!

[chadwick110]

I just replaced mine, but now the car won't start.

The other morning (the first cold one in Georgia), I turned the heat on for the first time (which, as I've read, is related to this issue). The coolant reservoir was depleted. I added more, then started driving to work the next day when I noticed there was smoke coming from under the hood. I pulled over, opened the hood and saw leaking coolant being boiled away into the smoke that stopped me.

So, I returned home. With the car off, I saw light bubbling from the area that is the Heater Bypass Valve. I also noticed that the reservoir was low(ish) again. I turned the cap to the reservior slowly open. The reservior quickly filled up, and coolant started flowing from the Heater Bypass Valve. At this point, I also heard a popping/sparking sound from where the Heater Bypass Valve is located.

Given that now, after replacing the valve, the car won't start (it started before), is it possible that the coolant leaking shorted out something that is now keeping my car from going? PLEASE HELP!

For completeness's sake: the car will turn over and rev, but won't start. Had jumper cables hooked up to make sure it wasn't a battery issue.

2002 Saab 9-5 with 114,000 miles.

[nordwulf]

Here some more pictures from when I changed my valve last year. Hose clamp pliers make it a lot easier to get the hoses off.

[saabfan9]

I came across this thread on a search...can anyone show some good pictures on the vacuum routing back there...the previous owner has that all a mess when I route the boost solenoid hoses correctly I will get no heat (I have been chasing a p1110 fault code that made me look back there in the first place)

there is a solenoid loose riveted to a bracket directly under the boost valve (forgive me if i'm using the wrong term) it looks exactly the same it is plugged in electrically but the vacuum lines are unplugged or just laying loose in the engine compartment. when I routed the boost solenoid correctly I had no engine light and a noticeable change in performance (but no heat)

any pictures back there or a good diagram (I did a google search and nothing helpful) any help would be greatly appreciated

[saabfan9]

hard to see but the solenoid mounted under the heater control valve i'm not sure how these hoses are supposed to be routed

[qqac]

The vacuum line with the red/white check valve plugs into the end of the solenoid. The nipple off the cylindrical side of the solenoid connects with a vacuum line to the top of the heat exchanger valve.

[Old Folklore]

Saabfab9 said:
I came across this thread on a search...can anyone show some good pictures on the vacuum routing back there...the previous owner has that all a mess when I route the boost solenoid hoses correctly I will get no heat (I have been chasing a p1110 fault code that made me look back there in the first place)

there is a solenoid loose riveted to a bracket directly under the boost valve (forgive me if i'm using the wrong term) it looks exactly the same it is plugged in electrically but the vacuum lines are unplugged or just laying loose in the engine compartment. when I routed the boost solenoid correctly I had no engine light and a noticeable change in performance (but no heat)

I have the same problem - can anyone shed some light? gonna need heat soon up here in Maine ! ! !

[Kazamario]

@Old Folklore, did you sort the P1110 out?

[Old Folklore]

@Old Folklore, did you sort the P1110 out?

Yes - two hoses were crossed, improperly connected. I had recently purchased my 9-5 from a local low end used car guy for small money, and then addressed several issues. This one was weird, but apparently someone somewhere crossed up the hoses - used car guy claimed no knowledge of course.
Anyway, all set ! ! ! Thanks, Kazamario, for checking.