Engine emits rattling noise between 2k to 3k rpm

Hi all,

Since about 2k miles, my M3\'s engine makes a rattle noise between 2k to 3k rpm for higher gears (3rd to 6th, more pronounce on higher gears) when I try to accelerate harder on those gears. The rattle is more pronounced with the power bottom on. On the other hand, no rattles in 1st or 2nd gear, or neutral. The sound emits from the driver side of the engine bay it seems.

This is the first v8 for me, and I was wondering if this is common? My transmission is 6mt.

Thanks for the guidance here!

Yep, most likely the normal intake rattle. It got really loud for me when I installed my Akrapovic exhaust.

Does it almost sound like the engines pinging and only makes the noise under light load between 2k to 3k rpm..?

The rattling noise is like a fluttering sound, but only there when under load (more aggressive throttling)

Yes, I have the exact same sound under the same conditions. I would love to know the reason too.

It is normal engine noise coming back out through the intake. If you are hearing it more on the left side that is because the hood vent on the left is connected to the intake. The dual-layer 2008-2009 US intake filter silences the rattle, at cost of air flow. Newer US or Euro filters and aftermarket filters do not.

After 9 months with an aftermarket filter I put the stock 2009 back in.

So is the general consensus that this is all airbox related?? I test drove a used m3 dct yesterday, and heard, upon acceleration, a rattling/fluttering...like wind trapped under paper....from what seemed to be the front left part of the vehicle? Almost a "crackling" or "rustling" actually...hard to describe. It wasn't there when the car was revved in neutral...

The dual-layer 2008-2009 US intake filter silences the rattle, at cost of air flow.

Very interesting. Five years and 35k km later I am yet to hear this. I am about to install a BMC filter sometime today. Mine is a '07 car.

Totally normal. Its not the airbox, its rather that it is a very open, large air filter and box so emitting all the sounds from the engine which what you here is the clatter and natural resonance of the valvetrain at those RPMS' and gears.

Love the mechanical sound of this car!

The one thing is you really never should be in a situation where you are accelerating in this rpm range in a high gear. You need to keep this thing about 5k rpms so it is never an issue in real life driving, atleast for me!

I hope that is what I'm hearing! Can definitely live with it if that's what's going on. I guess I mainly noticed it at lower speeds, when I would have to be in the lower rev range. Soot is the "air under paper" sound, correct". Almost a hybrid rattle/flutter sound?

Freaked me out, though . I have a GTO rt now, which makes a few noises, but not like that.

This forum is just amazing! Was looking for an answer to exactly same issue and guess what! Found it here

My car (late 2012) makes exactly same noise when accelerating at higher gears and low rpm.

It means green light to mod my car now

Part is a rattle but also I have logged data and if you are in too high of a gear and bogging the engine the knock control system is going wild as given this engine, if rpms are too low and you are in a high gear you are loading the system and the engine will knock unless the knock control starts working overtime so not sure if its a combination of dialed back combustion as it shows on the logging data.

Longwong wrote

Part is a rattle but also I have logged data and if you are in too high of a gear and bogging the engine the knock control system is going wild as given this engine, if rpms are too low and you are in a high gear you are loading the system and the engine will knock unless the knock control starts working overtime so not sure if its a combination of dialed back combustion as it shows on the logging data.

Does this sound like a fast clattering noise? Mine does it between 1,600 and 2,200 revs on partial load but stops if you take your foot off the accelerator pedal altogether. Much more noticable at lower speeds as well. I've had the car for 12months but only noticed it last week! Must be because the stereo is usually turned up.

Also have this sound, it is exactly like pinging at sub 2000 rpm, whereafter it disappears completely. Is it a cause for concern/investigation?

Plugs?? Keep it fresh. These engines love new spark plugs.

I have it too. Very annoying. I thought it was the heat shield as it became really noticeable when I went from the stock xpipe to a catless one (no resonators, too). Happens only when under load, 2500-2800 rpm. It is the worst when the engine is bogged and under load. This is unfortunate since I have the DCT and prefer to use auto mode in the neighborhood since it is quieter.

Could it be the heat shield instead of the intake?

Put up a vid?

Relax guys, it is just the sound of the engine breathing!

4corners wrote

Plugs?? Keep it fresh. These engines love new spark plugs.

Agree, even when my rod bearings were nearly gone it sounded better with fresh plugs!

Is there a way to fix the intake rattle without going back to the old filter? I removed the one that came with my 08 M3 (I got othe car second hand) and put in a Stage 2 AFE filter and arm. Around the same time I went catless and resonatorless so the sound is on steroids.