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Discussion Starter · #1 ·
Hello

Missus has a '02 9-5 2.3T Vector sedan with an auto tranny.

When idling at some 7-800 rpm, there is resonance in the chassis. The whole car vibrates and hums. It's not very intrusive really, but enough to be mildly annoying when you realize that if you poke the gas pedal ever so slightly and raise the revs 50-100 rpm it disappears and the engine is as smooth as one could wish for. Then you release the gas pedal and it goes back to sounding like a diesel.

I would like to adjust the idle up a little, but I'm not familiar with Trionics and their computerized throttle and as far as I understand, there are different ways depending on engine type and whatnot.

Any pointers?
 

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You can adjust idle speed using Tech2 computer (dealer or well equipped indy). I believe it adjust at 50rpm intervals.

However, vibration might be due to something else (especially if it was not there before). If you replaced the serpentine belt with a new (short) one, people do complain about increased engine vibration at idle.

Also, at this age motor mounts start slowly giving up, transferring vibration to the car and making idle feel a little more rough. A decent shop can inspect them and suggest which ones to replace.

Cheers
 

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Discussion Starter · #3 ·
We have only owned the car for a couple of months, so I don't really know if it has been like this all the time or if the belt is changed.

In lack of a Tech2, is there mayhaps some screw I can turn a bit?

The SAAB service shop here are ****ers, so methinks I'll do the rocket scientist troubleshoot and lift the car and whack the motor mounts with something, pretending to know the difference between old and fresh rubber.

Thank you for your help!
 

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The roughness at idle that you are experiencing is very common with this engine. There is even a TSB that addresses this subject and suggests raising the idle by (25-50 ?) rpm if its a major nuisance. Not sure if it takes Tech II to adjust it or not. The factory setting I believe is 835 rpm's. You mention yours is 700-800 rpm's. That could be your problem there!

Walmark is correct in both of his points. If you have a short belt it is known to increase the roughness of the engine. Engine mounts could also be a major factor, especially considering the age of your car!
 

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Discussion Starter · #5 ·
You make our new fine SAAB sound geriatric! ;_;

I'm surprised you mention the mounts, as our other cars are 13 and 21 years old and have no apparent problems.

Although those have a V6 and V8 respectively. I dunno about these four-bangers - I guess their precious few pistons comparatively make more of a ruckus in the engine.
 

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It's not only saab. I had a 92 toyota camry V6 and the engine was simply jumping off from the mounts. The right side mount was so worn that there was barely any rubber left, just metal rattling on metal.

I'm not sure if it's ok but when my mechanic was checking the mounts he did it like this (auto):
-put car into D, keep brake pressed and add a little gas, look how far engine moves under load
-do the same in reverse. You need to have someone do it while you look at the engine, or try to peek at it from the driver seat with the hood open (you shouold see the top of it).

No clue if that is a sound advice, but that's what he did. The engine should move a little, but not too much. If it jumps all the way between the radiator and the firewall, you definitely need new mounts :D
 

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Discussion Starter · #7 ·
Say - that's a rather clever method! I'll try it. Thanks!

As for the idle, I take it there are no knobs to turn, only computer tricks?
 

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The only adjustment available is via computer tricks - need the Tech II tool to adjust. A great big 4cyl connected to an automatic transmission will always be rough at idle and in gear. I just put mine in neutral at stops.
 
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