w204 C220 CDI OM646 - Rumbling sound underneath

[starrzo]

Hey guys,

This is going to be hard to describe accurately, but my car has started making a rumbling/rattling sound underneath, very noticeable, especially at low speed and particularly over slightly rough ground.

At first I thought it could be the undertrays or some loose cover - but I've removed them all and secured anything that could move.

It's hard to tell where it is coming from, sometimes it feels like the rear passenger side, and other times it sounds like the front.

I know it'd be hard to diagnose online, but anybody have any ideas?

Cheers.

 

[A.J.]

Exhaust ? loose baffles ? mountings ? I'm not a mechanical genius by any means though

 

[starrzo]

Exhaust ? loose baffles ? mountings ? I'm not a mechanical genius by any means though

I'm no mechanucal genius either, but I'm pretty sure it isn't loose baffles or the exhaust. I've been underneath with it up on ramps and tried to shake and kick everything, lol, but nothing is obviously "loose"

 

[LostKiwi]

Usual culprit is a loose heatshield.

 

[John Laidlaw]

If it was just rumbling I’d be looking at the tyres, when wide low profiles on certain makes get beyond half worn they rumble almost mimicking worn bearing rumble

 

[starrzo]

Had somebody look at it this morning. Front passenger arm is knackered and driver side one isn't in great shape either. Getting both replaced today