Squeaky, "chuckling" noise while engine braking (sound clips available)

[puklars]

Hi all,
My 2001 9-5 estate has recently developed a strange noise. The noise occurs basically only when engine braking, and it could best be described as some form of squeaky, metallic and rhythmic bird tweet or chuckling. The sound seems to come from somewhere around the gear selector area, but it is really hard to pinpoint the exact location from inside the car. I have included links to sound files recorded today.

The noise is strongest during engine braking from above ca 80 kph, when the gearbox has reached "lock up" mode (then I assume the engine braking torque is also the greatest for this type of gearbox).

The noise also occurs while in reverse gear, and occasionally over speed bumps. I am convinced the noise emits only when the drivetrain assembly is exposed to "negative torque", i.e. engine braking or reversing.

Here is a sound file of my 9-5 during engine braking from around 95 kph: https://www.dropbox.com/s/thavfwxgfd...oms95.m4a?dl=0

...and during engine braking from around 50 kph: https://www.dropbox.com/s/thavfwxgfd...oms95.m4a?dl=0

Also, the same squeaky sound can be produced while rocking the car back and forth with gearbox in "P" position:
https://www.dropbox.com/s/7yfy4x0e55...Undre.m4a?dl=0

I would be really happy if anyone has an idea of what this might be or even recognizes it! Do you think the sound could come from one of the engine mounts or perhaps subframe bushings?

Best wishes from Sweden,
puklars

[Dave 2 93s]

Hi
I know this regarding a 93, but it's worth checking , even if it's to eliminate it from your possibles.

[FONT=Times New Roman]https://www.genuinesaab.com/psi/files/93pop.htm[/FONT]
Here is the index that this came from.

https://www.genuinesaab.com/psi/index.htm

Hope this helps
Dave
[FONT=Times New Roman][/FONT]

[puklars]

Hi Dave,
thanks, I will definitely look into the possibility of re-torqueing.

All the best,
puklars

[nordwulf]

That's an unusual sound and haven't heard something like that before. It's a long shot but check the front transmission torque arm. It has a rubber insert which wears and detoriates over time and I can imagine it will start making noises when the rubber is worn away. Just a wild guess.

[puklars]

That's an unusual sound and haven't heard something like that before. It's a long shot but check the front transmission torque arm. It has a rubber insert which wears and detoriates over time and I can imagine it will start making noises when the rubber is worn away. Just a wild guess.

Wulf,
I suspected the torque arm at first. Ordered a new one (they are inexpensive), stock version. I wanted to look at the behavior of the torque arm myself, so I made this video clip to show the torque arm (and total engine flex) while shifting through P - N - D a couple of times at idle rpm:

https://www.dropbox.com/s/c7omgxld54..._8278.m4v?dl=0

Does the amount of engine/tranny rotation/flex when shifting seem normal to you? Though not new, the original torque arm looks pretty ok to me. I will nonetheless put the new one in place to see if it makes any difference. The new part does seem to have a decent amount of flex in the "square" end just like the old one does in the video. This is part of the design, I believe. Some people seem to put PU-bushings there for extra stiffness, but I would rather not, since this is also said to increase engine vibration and noise.

As an engineer, I tend to be overly theoretic when it comes to solving mysterious car troubles like this. Maybe I should just make my way to the garage and start working

[nordwulf]

That looks normal in the video, it does have some flex and play by design. I recently replaced mine as well just because the rubber looked a bit old and was experiencing clunking from the front end. But I didn't notice any difference. However, they are inexpensive and easy to replace as you mentioned.

It may be best to have a qualified Saab mechanic check it out and at least provide a diagnosis. It sounds like it may be something inside the gearbox but that's difficult to determine from just a sound file.

[puklars]

Ok, thanks for the input. I will go on to inspect the rest of the mounts and finally subframe bushings for any abnormal amount of flex... The car does drive well on the road, so the subframe bushings are perhaps not totally shot just yet. Already checked the transmission mount under the battery bay - looks ok to me, apart from all the dust collected

Good idea to have someone qualified have a look at it. Maybe a quicker way to find the answer in the end.

[Dave 2 93s]

Hi
I've listened again and initially thought exhaust rubber worn, moved or missing causing the chirpy metallic sound of your exhaust's bracket etching it's name somewhere . Then from the realms far beyond the back of beyond. I remembered a friend who was ford trained talking to a gm trained mechanic about a mysterious rattle he was struggling to find. The other mechanic went straight to the exhaust and gave it a firm shaking and the noise appeared. It turned out that the inside of the cat that he described as a brick, had cracked. A new cat would be quite an expensive repair, but he overcame the need to replace it with a well placed clout from the ball end of a hammer. This squeezed the cat brick enough to stop it rattling anymore.
Just thought I would share that with you.
Hope it helps.(if it doesn't, forget I said it)
Dave
Now I've typed all that, I think I should watch the video.

[puklars]

Dave,
That's a very good thought. I'll definitely check this out as well. I will try to shake the exhaust a bit to see if I'm able to reproduce the noise.

Will keep you posted.