whyjay

Wife has had her 2018 GLS450 for about a year. I'm not sure when this started but everytime I close either of the rear doors or go over multiple road bumps in a quick sequence, I hear this vibration/rattle. It sounds like it could be normal, especially for a vehicle this size, but thought of checking with you guys if you've experienced anything similar. It's not intermittent, it's everytime. I took everything out of the cargo area including the spare. It just sounds like it's coming from the body/chassis. Super bizarre.

🙏Thanks for the help.

Jpkcpa

whyjay

Finally figured out the odd buzzing/rattle noise when shutting the rear doors or going over bumps. I believe it's caused by the very bottom of the rear bumper. If you tap it with your hand, you will hear an odd rattle, almost like it was clipped on correctly. I checked a couple of GLS450s at the office and they produced the same sound. I checked the previous-gen GL and they don't have this sound. When I take the car in, I'll let them know and see if there's something they can do, otherwise, I'll learn to live with it.

iridium18

whyjay - thanks for the update - we also have a MY18 GLS450, so am very interested to hear a follow-up with your dealer. Thanks, Steve

whyjay

Apologies for the slow response but I did take the vehicle in about a month ago. As predicted, there was a cable harness behind the rear bumper that had come loose. This was reattached in an improved fashion (likely zip ties ) by the dealer. The odd rattling/buzzing noise was in fact improved dramatically when the dealer discovered a shielding plate for the exhaust was not quite situated correctly and was making a ton of excessive noise (their words). They repositioned the plate and bolted it down further. Some of the noise is there but it's livable now. I'll keep an ear out further but I love my mblynnwood dealership as they go out of their way to investigate.

Anyway, hope these findings help someone.