[Beemermike]

Hi guys,

Since I owned my 2008 Steptronic 325i the engine would output a "Cracking" or a "Crackling" noise on rapid acceleration in throttle kickdown mode (See the video at the end).

In addition to the above, the car had a lot of vibration coming from the engine at startup, and from the steering rack which was very apparent at low speed turns when car was in 2nd or 3rd gear at low RPM.

Both the crackling sound on acceleration and excessive vibrations were caused by heavily worn out engine mounts, where one of the engine mounts sat lower than the other and apparently made contact with the steering rack.

After replacement, the crackling noise is completely gone, and the steering is smooth as butter (Also thanks to newly fitted Michelin PS5's replacing Bridgestone RFT's).

I hope that somebody with a similar problem finds this post helpful, link to the video with the crackling sound for comparison below:

https://www.youtube.com/shorts/3UlUishobSc

[Phil325i]

Thanks for the info. I keep thinking my mounts should need replacing (after 130,000 miles) but there's no vibration or engine shake. I have the OEM 'active' mounts that respond to a vacuum feed from the engine. Were yours that kind of mount, or standard?

[Beemermike]

Originally Posted by Phil325i

Thanks for the info. I keep thinking my mounts should need replacing (after 130,000 miles) but there's no vibration or engine shake. I have the OEM 'active' mounts that respond to a vacuum feed from the engine. Were yours that kind of mount, or standard?

Hi Phil, no my mounts are of the standard rubber type (Part no. 22116773745). My car is an 08 with 42k miles and had its original factory mounts, I have to say that the difference in smoothness of the car was incredible, although I slightly miss the raw feel of the engine on startup - now I just press the button and... well there isn't much except from the sound

They seem to be relatively easy to inspect, so I would suggest doing so next time you find yourself or your mechanic underneath the car.