Rotten eggs smell with bottom engine rattling noises

[Matyoka]

Sorry guys, busy couple of days...yesterday I took the X5 to a local 3rd party place 30 minutes away(Desert BMW) and they failed to find the rattle or reproduce the noise. I asked them to give it an other go today on a cold start and BAAAMM, there it was. They put it up and apparently a loose bracket that holds the Power Steering line was causing the ruckus. Replaced the cabin filters last week so they have no idea on smell... or P/S oil tank rattle.

Ard: NO check engine lights, nothing at all.

This is directly from the invoice:



Lev

[Matyoka]

Originally Posted by bcredliner

Is there an intermittent rattle if the engine is just idling? If it is only under acceleration the issue may be engine timing related or low octane gas.

Both idle and low speed driving caused the rattling.

[Matyoka]

Originally Posted by ard

Just to clarify...no check engine lights, no codes??

No Sir, no codes or engine lights... ran the scanner a few weeks ago and all clear. But at least now we know it was not an internal issue. I am still worried about that P/S tank rattle however... it was big enough to make that bracket come loose. I didn't check to see if this job fixed it or not, but I will soon.

[Matyoka]

Originally Posted by andrewwynn

The shaking reservoir suggests something on the serpentine belt is causing a shake or possibly engine mount.

I use this app:

https://apps.apple.com/app/id1089589547

To find vibrating things. You can find the frequency and compare to rotational speed of each accessory on the serpentine belt with a little math. Take video at 240 fps and count frames.

Also the best way to find sound source is an FFT app.

This is the one I use:

https://apps.apple.com/app/id298840058

I've found a few bad wheel bearings using this app.

Thanks Andrew!!!!