Hoping someone can help me identify this noise

[koolkat1973]

MY08 3.0si has 131K miles on it now and it is making this noise when I start the car. The noise does not go away even when the engine has warm up. Does anyone here know what this noise is?

https://youtu.be/c_Gwz9orhF4

Thanks in advance.

[rpoitras]

If it's not something obvious like the belt, alternator, tensioner, pulley, etc. (hard to tell from video) than to me it sounds like a bad DISA valve. There are two right in that area. One is on the driver's side of the engine and has a wire going to it. If you look down it's a small thin box attached to the intake. You can unplug it while the engine is running and if the noise stops it's the "outer DISA" that's bad. Easy to change. The other one is above the outer but underneath the intake manifold which must be removed to replace it. This is the "inner DISA". If you have INPA you can activate each one separately and listen to hear that they are at least functioning. They are flaps attached to motors that open or close the air passages inside the manifold. When they go bad usually the spindle of the flap that attaches to the motor fails or the gears so the flap cannot stay closed due to the air suction. The flap then flutters making the noise. On older N52's (I don't believe '08s are included, but could be wrong) the spindle and flap would fall apart inside the manifold potentially causing engine damage.

I believe the inner DISA, when failed, causes loss in low end power because that's when it's supposed to be working.

Just a guess here.

[Sschwab]

Could be DISA, but almost sounds like a fan hitting plastic.

[koolkat1973]

Originally Posted by rpoitras

If it's not something obvious like the belt, alternator, tensioner, pulley, etc. (hard to tell from video) than to me it sounds like a bad DISA valve. There are two right in that area. One is on the driver's side of the engine and has a wire going to it. If you look down it's a small thin box attached to the intake. You can unplug it while the engine is running and if the noise stops it's the "outer DISA" that's bad. Easy to change. The other one is above the outer but underneath the intake manifold which must be removed to replace it. This is the "inner DISA". If you have INPA you can activate each one separately and listen to hear that they are at least functioning. They are flaps attached to motors that open or close the air passages inside the manifold. When they go bad usually the spindle of the flap that attaches to the motor fails or the gears so the flap cannot stay closed due to the air suction. The flap then flutters making the noise. On older N52's (I don't believe '08s are included, but could be wrong) the spindle and flap would fall apart inside the manifold potentially causing engine damage.

I believe the inner DISA, when failed, causes loss in low end power because that's when it's supposed to be working.

Just a guess here.

Thank you very much for the suggestion. I will look into the DISA valve.