u/JustNikeThat

Hey everyone, hoping to get some diagnostic help for my 2010 E90.

For the past few weeks, I’ve been hearing a knocking/spring-like noise coming from the rear/trunk area. There’s nothing loose in the trunk, so I’ve ruled out cargo.

Here are the symptoms:

• When it happens: Most noticeable when accelerating from a standstill, but also happens intermittently during normal driving.
• The sound: A distinct "knock" or "springy" noise.
• Vehicle info: 210,000 km. To my knowledge, the suspension components are all original.

Could this be a blown shock mount, subframe bushing, or something else entirely? Any advice on what to inspect first would be greatly appreciated!