Guys,

My 2010 E350 makes a sort of rumbling/growling sound when I drive it and I’m wondering what it could be. It seems to be coming from the passengers side near the rear of the engine. It’s not exactly an exhaust leak I dont think. It seems like it could be a leak from something else but I just can’t tell what. It seems to happen more after
initial start up and I’m wondering if there could be a leak in like something that helps return warm exhaust gases into the intake manifold to help with cold starts? Of course it’s really hard to diagnose this because all the stupid engine and undercarriage coverings mean you actually can’t see the engine. Has anyone else experienced anything like this? Any tips are appreciated.

Mike

 

If it only makes the noise while moving, it's more likely drivetrain related, maybe put in on a lift with the shields removed and listen?

 

it also makes the noise if I step on the gas and brake at the same time, so when the car isn’t moving. Don’t think it’s drivetrain related.

 

Have you checked the engine mounts? When they collapse, the upper part of the mount sits directly on the lower part (no cushion between), transferring any engine vibration to the chassis.

You description sounds quite familiar.

 

Too many options to guess, you could have someone do the brake and gas while you listen under the hood, to pinpoint the noise you can put an old paper towel tube to your ear and move it around until you find it, could be motor mounts and tranny mount as Dmatre suggests

 

That’s a great point. It feels like a vibration/rough running and that could definitely be it. I’ll look into it.

 

Easy engine mount check. Move car so you have little room in front. Put it in gear with firm press on brake. Put even the parking brake on.

With the hood open give it a good gas and observe if the engine moves up on one side. If it does you need mounts.