SaabCentral Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
After having started the car in the cold this morning (-12 degrees Celcius) a strange noise occured (follow link to Youtube belo2). I seems to be coming from somewhere behind the ACC-unit, and it kept on going for a few minutes. I'm pretty sure it has something to do with the cold, which also corresponds with the sound going away as the car had warmed up. The noise appeared again when i started up to drive home from work - again with the car being very cold, and again with it going away after a few minutes of driving.

Does anyone have any idea about what it could be, and if i should be worried and do something about it?

https://youtu.be/_B1iD1Eg-6Y


/K
 

·
Registered
Joined
·
2,026 Posts
That sound is very familiar. It is most likely coming from your cabin ventilation blower.

As a test to verify: next time it happens, push the OFF button on the ACC panel. If the squealing sound immediately stops...that would be enough proof for me.

If you want to be sure: when it starts squealing, use the fan speed buttons on the ACC panel to manually override the ACC's fan speed command. As you change the speed up/down, observe whether the frequency of the sound tracks along with it.
 

·
Registered
Joined
·
3,938 Posts
Since the cure is R&R of the blower motor which is a fairly big job I'd ignore it as long as it is only during cold weather. Until the noise becomes unbearable you need not do anything as the motor itself will run just fine.

It is possible frost is getting into the blower motor bearing which is a temporary problem.

The bearing is accessible, sort of, and on my Alfa Romeo 164 I have successfully sprayed silicone lubricant at the bearing. Short term fix though. There's a metal spring retainer clip that rusts and deposits rust bits into the motor bearing causing noise and wear. Eventually, I put a SAAB spec motor into my Alfa, it's the same part from Bosch. Valeo made and supplied the hvac systems to both SAAB and FIAT group.

The bearing is a sleeve bearing at the left end of the motor/fan unit. You can see the spring clip and the bearing where it fits into the plastic heater box after removing the plastic cover from the false bulkhead area. The replacement motor is a Bosch unit. It's a shame the whole thing has to be replaced when usually only this bearing is the issue.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #4 ·
Thanks for your input!

I also assumed it was the blower motor, but it in fact turned out to be the cabin temperature sensor. The sensor has a small fan, and that fan has a bearing. This bearing wears out after a long life of good service - with the cold possibly intensifying the symptoms - causing the strange sound. A new sensor is pretty expensive, especially when compared to the cheap solution of applying a drop of sewing machine oil (or it's equivalent) on the fans shaft. I expect the sound to come back after a while, but hopefully this has cured it for a few months.
 

·
Registered
Joined
·
1,177 Posts
:) See IF you can find a used sensor gizmo from a 2 litre.. Pre '93 9000.
Their wee fan motors were of superior design, in that they had 2 real motor bearings.
Much more durable.
 

·
Registered
Joined
·
2,986 Posts
9-5 uses the same cabin air sensor. If you're combing the junkyards for useful bits... Most 9-5's will have lower mileage compared to 9K's
 

·
Registered
Joined
·
44 Posts
My sensor recently did this as well, I pulled it apart then pulled out all the dust and crud out of it and sprayed some electrical cleaner on it and haven't had any noise since!
 
1 - 9 of 9 Posts
Top