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Discussion Starter · #1 ·
My '96 CSE 2.0LPT auto has this strange thing on the bulkhead next to the MAP sensor. While idling, it periodically makes a loud buzzing noise, more frequently if I hold my foot on the brake.

None of the other four 9000s I've ever owned (including my '96 Aero) has one. What on Earth is it?

Should it be clearly audible inside and outside the car with the bonnet closed?

 

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BillJ, that is a vacuum switch for the cruise control. Though I'm suprised to see it on a '96, I thought that system was only fitted to models up to '94.
It works by releasing the vacuum from the cruise system when you hit the clutch or brake etc. (hence the buzzing).
 

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Discussion Starter · #5 ·
DrD, the car doesn't have cruise control. In fact, it's the only 9000 I've ever owned that didn't. My '95 CSE and '96 Aero don't have this "thing" and I'm pretty sure my '87 2.0T and '90 CD 2.3T didn't have it either. All have (or had) cruise control.
 

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as to should it be clearly audible... I can hear my pump running... just dabs the brakes a few times you should hear it cut in...

Looks like your vacuum pump is mounted to a bracket on the back of the engine under the inlet manifold, to the left of oil pipe (ask you look down) so I would imagine it would be more audible than mine which is behind the NS headlamp.
 

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Discussion Starter · #8 ·
Originally posted by Leon (murphwiz):
[qb]So whats the prize again?[/qb][/b]
You get to take me for a ride in your car (finally) next time we meet


It would make sense, since the thing buzzes at much more frequent intervals when I have my foot on the brake. As far as I can see, that hose on the right goes to what I think must be the servo vacuum hose. So it's auto-only? How come ylee has one on his Aero? I thought his was manual.

The loud buzzing noise doesn't seem to come from anywhere else. As far as I can tell it comes from that valve itself.
 

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So it's auto-only? How come ylee has one on his Aero? I thought his was manual.[/b]
That particular part is listed as fitted to B204 Turbo Auto 94-98
Yup just searched the part number, auto only... perhaps they used it for something else under a different number
Same part and number for NG900, 9000 & 9-5 all auto only, not on 9-3 as i believed they used engine driven pump, where distributor would normally be.
 

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Discussion Starter · #10 ·
Thanks, Leon.
I think that pretty much clears it up. It is indeed a B204 turbo auto.
Now I just have to try to figure out what the rattle is that my dad is reporting. I thought it might be that buzzing, but I don't think it is now.

Time for a new thread, perhaps.
 

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the car doesn't have cruise control[/b]
Bill, that is definitely a vacuum switch for cruise control.

You may not have a switch for cruise control, but if you check out http://www.sudburys.co.uk/saab/service/stockparts.htm they have a cruise kit for the 9k for £140.
I may be wrong, but there can be no way that all of the parts for cruise cost only £140, my guess is that the 9k is fitted for cruise, but differ in the fact that they have indicator stalks with or without cruise wiring (the kit will just be a stalk).
Dig around a bit more, follow the vacuum line, if the rest of the gear for cruise is fitted you should be able to find a vacuum pump, and the throttle control unit.
 

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Bill, does the car have TCS? It's located in the same place as the TCS safety valve on my car, but it looks totally different to mine, no apparent means for the valve to vent of course?!! Summat to do with the kickdown motor on an Auto with TCS perhaps?
 

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Bill, that is definitely a vacuum switch for cruise control.  [/b]
In this particular case its not..
The vacuum regulator for the cruise control is a completely different part number, and is aleedgedly located under the dash somewhere... in this location it is indeed a pressure monitor for the vacuum assitance pump for the brake servo.
 

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Leon, somehow I managed to miss your first reply, must have been before the coffee kicked in
Although I recognised the part I thought that the location and the year was unusual.
Having one yourself you were obviously privvy to extra info, Bill didn't mention a part number, nor where the vacuum line went, either of which would have been more of a give-away.
 

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Discussion Starter · #20 ·
OK, guys, in summary:

The car definitely doesn't have TCS (I think only the 2.3 FPT got that?) When I noticed this gadget while looking at the car, the first thing I asked the dealer was "does it have TCS?"
I've since had the throttle body off to clean it and it is just a standard mechanically-operated throttle.

The car also doesn't have cruise control, although I accept that it's possible that some cruise control parts may be present. All my other 9000s have had cruise control ('87, '90, '95, '96 models) and none had this gadget. All of these had manual transmission. This car is the only auto I've owned.

I don't have the part number and can't get it at the moment as the car currently lives with my dad 450 miles and a ferry crossing away.

I can't experiment with disconnecting it for the same reason I can't read the part number.

I'm not into cleaning underbonnet components as they only get seen by grease-monkeys such as ourselves and I reckon oily deposits are good for keeping corrosion away (even from plastic components - you can't be too careful)

The rubber hose tees into a hose at the rear of the engine that comes off the plenum chamber and I think probably goes to the brake servo. This is from memory, though.

Even when I'm not braking and the engine is just idling in "Park", the gadget buzzes periodically. However, it is more frequent if I press the brake but never buzzes constantly.

Any help? I think Leon has probably sussed it, though.
 
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