Fluttering noise in engine while accelerating at a fast rate

I would check to see if there is a restriction in the fuel return lines. Also the o2 sensor might be lazy.

Hello,

Sounds like your engine mounts need to be replaced. Thats a common issue on ML's hope that helps.

I would need to know what vehicle this is? 4 Cylinder. V6? 3.0? There are a few things it could be,

If the Engine is Moving, it could be hitting something so I would check the Motor Mounts (Happens quite Frequently on Taurus)

Check the Tension of your Serpentine Belt

This sounds on the base of it to be pre ignition, if so the moment you take the foot off the gas it goes? The cure is to retard the ignition timing slightly, have you recently changed your octane of fuel? this will also cause this?
The noise is caused by the expansion of the compressed gases expanding before the piston reaches top dead centre causing the piston to \'rattle\' left unchecked will cause permanent damage and engine failure

It sounds like the engine is "pinging" as you are speeding up. If so, this is often caused by plugged EGR passages at the intake elbow or a non-functioning EGR valve. The EGR valve allows a small amount of exhaust gasses back into the intake manifold to slow and cool the combustion down slightly to prevent the fuel from burning too fast [which we hear as a pinging sound] and it helps reduce emissions at the tailpipe. When the valve quits working or the passages get blocked the pinging sound will be heard when accelerating or at higher speeds & heavier loads. Pinging is not good for an engine and should be checked out as soon as possible. A quick test drive with a good service tech should quickly narrow down the cause of the noise. Hope this helps and good luck!

DIRTY INJECTORS OR SPARK PLUGS FOULED OUT.

Probably one of your rod bearings is going out and knocking when under load. Get it fixed before it stops completely.

Your clutch is goin g out on it.

if its auto it sounds like the transmisson is sllipping no quick fix
if its manual the clucth is slipping try adjusting if there is no adjustment then clutch needs replacing

Try rear wheel bearings. The cause a roaring noise that increases with acceleration. Sounds very similar to loud road noise.