[Aragorn30d]

Noticed this for a while now, but its starting to niggle so wondering if anyone has had this before.

While driving, the car makes a very faint metallic rattle at very specific points in the rev range.

Its usually around 2000rpm, and only does it when your accellerating.

If you apply some throttle from say 1500rpm, the car will begin accellerating, then as it approaches 2000rpm the rattle will appear, then if you continue accellerating it will disappear/fade away by around 2500rpm.

If you manage to hold the car within that band, say in a higher gear uphill, it'll continue rattling constantly. If you lift of the throttle a bit to just maintain speed so your no longer accellerating, the noise goes away.

Its quiet enough that having the radio on at a modest volume pretty much drowns it out and you dont hear it, but its there all the time. Doesnt seem to change vs temperature either, it'll do it first thing in the morning when i join the dual carriageway with the engine cold, and it'll do it after a 40mile drive with the engine fully warmed up.

Oddly i dont recall hearing it at full throttle, but maybe thats just because your busy driving the car rather than listening for noises.

Any ideas?

[Rich_D]

Manual or auto?

[jayooo]

Is yours manual or auto? Clutch chatter, DMF?

Check all heat shields/brackets too - I had a similar issue in a previous car and the cause was a shield near the exhaust manifold.

Can you hear it if you stick your head under the bonnet and get somebody to hold the revs at the right RPM to trigger it, or is it only on the move when the engine is under load?

[Icekube]

its a manual

i dont imagine it would be clutch or DMF related, as it would be fully locked up at those points. and if the clutch was that broken it was making noise at those RPM, it would only get worse with increased rpm.

could be the timing chain guides? :s

[Aragorn30d]

Revving the engine in neutral doesnt do it, theres not enough load on it. Dont usually hear it in 1st or 2nd either, thats not to say it doesnt happen, but likely just that your generally applying less power when in those gears.

I did think/worry about the timing chain, but i dont see why the chain would care about load, the tension on the chain isnt going change much if you go from 20% throttle to 50% throttle surely?

It could be the clutch/DMF, but it doesnt exbibit the usual DMF signs like judderings etc. The car has done 145k. Previous owner claimed the clutch and flywheel was done by the previous owner to him (the guy i bought it from didnt have it long), but the "proof" he provided was an estimate of works from BMW, and when i queried the dealer they had no record of it being done.

[chrissyw]

M57 engine?

[Aragorn30d]

yep, M57.

Did some more listening the other day on the motorway.

No throttle or very mild throttle just maintaining speed = no noise
Add a bit more to start gentle accelleration, noise appears and will go on continuously if you hold the throttle there, until the revs rise beyond maybe 2500rpm or so.
If you really put the foot down though, the noise vanishes.

Whats even more peculiar, is that if you lift your foot off the throttle after accellerating hard, as you pass thru the throttle position where the rattle would happen, the rattle appears again momentarily.

[Abphoria]

Mine is going through the exact same problem... and I was worrying about the clutch, release bearing and flywheel - but it just doesn't add up to me either.

I have literally just got back from a little local meet and a friend of mine said he could here it clearly being in the car behind me, saying it sounds like a hub bearing issue.

I will check it out tomorrow in any event as this could just be an additional failure - but mine is as yours is, around 2000-3000 rpm. If I find anything significant I will respond as soon as possible.

[kevinmcelroy84]

Hi dis you ever find out what the problem as my 2006 330d e90 msport
Manuel just started doing the same

[rasa bmw]

has it got a dpf or gutted ?

[StiffUpperLens]

I have exactly the same problem, only mine's an N57 and Auto. Its stumped me, I can't find the source...

Following this thread in case anyone has a light bulb moment...

[BMW33]

Originally Posted by StiffUpperLens

I have exactly the same problem, only mine's an N57 and Auto. Its stumped me, I can't find the source...

Following this thread in case anyone has a light bulb moment...

Hi mate as you have said it's an N57.. I heard the same noise under throttle like you said n57 engine auto.. which got louder as you went up the rev range. I have been advised not to drive the vehicle as the bottom end is knocking, possible big end bearing failure. Have a google it seems to be a known issue on the N57.

[jaxone]

Originally Posted by BMW33

Hi mate as you have said it's an N57.. I heard the same noise under throttle like you said n57 engine auto.. which got louder as you went up the rev range. I have been advised not to drive the vehicle as the bottom end is knocking, possible big end bearing failure. Have a google it seems to be a known issue on the N57.

I drive an F01 with same N57 engine ... mine developed such a noise lately but the noise is there only if I push it really hard from 1st gear ... I hear the metallic noise up until 3rd gear if I keep it floored.
If I am in 3rd and I let off the speeder for a second or so , then I floor it again , the noise is not present anymore.... so I guess might be fuel pump related or fuel pump or injectors (even if all 6 are new).

If I drive normally nothing , no noise ,nothing.
If I push it after I am at 40-50km/h , again no rattle or metallic sound.

On mine I am 100% sure is not the bottom end .. when that goes you hear it also in neutral and while standing still.

[Croddlebopper]

Originally Posted by Aragorn30d

Revving the engine in neutral doesnt do it, theres not enough load on it. Dont usually hear it in 1st or 2nd either, thats not to say it doesnt happen, but likely just that your generally applying less power when in those gears.

I did think/worry about the timing chain, but i dont see why the chain would care about load, the tension on the chain isnt going change much if you go from 20% throttle to 50% throttle surely?

It could be the clutch/DMF, but it doesnt exbibit the usual DMF signs like judderings etc. The car has done 145k. Previous owner claimed the clutch and flywheel was done by the previous owner to him (the guy i bought it from didnt have it long), but the "proof" he provided was an estimate of works from BMW, and when i queried the dealer they had no record of it being done.

I agree I can't think it could be timing chain as it's not exposed to huge variations in load? Big ends are normally more evident at low rpm..
How about injectors? Not sure what tech your motor has but I had a Merc which "rattled" under load at certain rpm and it was due to the copper seal washer under the injectors being worn. When it got really bad you could smell exhaust through the air vents?

[StiffUpperLens]

Sorry it's been ages since I checked this thread.

I don't think it's the big end, very different noise.

It sounds like a glass jar full of tiny screws rattling around.

My theory is it may be an idler pulley or possibly a crack in the exhaust manifold.

The noise used to go away as the engine warmed up, but now its pretty much always there from about 1000rpm to 2500 rpm.

I'm about to pull of the intake to clean the valves and replace glow plug module so I'll have a decent poke around then and get back to you all if i find anything of interest.

[BMW33]

Originally Posted by jaxone

I drive an F01 with same N57 engine ... mine developed such a noise lately but the noise is there only if I push it really hard from 1st gear ... I hear the metallic noise up until 3rd gear if I keep it floored.
If I am in 3rd and I let off the speeder for a second or so , then I floor it again , the noise is not present anymore.... so I guess might be fuel pump related or fuel pump or injectors (even if all 6 are new).

If I drive normally nothing , no noise ,nothing.
If I push it after I am at 40-50km/h , again no rattle or metallic sound.

On mine I am 100% sure is not the bottom end .. when that goes you hear it also in neutral and while standing still.

Well I do hope your issue is not as big as mine was.. soon after the knocking I had my car inspected by a specialist, I was told my bearing one has failed. This then meant I has to go down the route of a rebuild. It was painful to say the least but I went ahead had all the bearings done couple of pistons and one glow plug had broke & fell on to the piston which ruined the block liners. So all in I had the block liners done couple of pistons bearing shells along with new chains glow plugs the engine gaskets & seals etc.

[rasa bmw]

Originally Posted by BMW33

Well I do hope your issue is not as big as mine was.. soon after the knocking I had my car inspected by a specialist, I was told my bearing one has failed. This then meant I has to go down the route of a rebuild. It was painful to say the least but I went ahead had all the bearings done couple of pistons and one glow plug had broke & fell on to the piston which ruined the block liners. So all in I had the block liners done couple of pistons bearing shells along with new chains glow plugs the engine gaskets & seals etc.

ouch,,cost ? and by who ?etc may help others

[Billyh1997]

https://youtube.com/shorts/vObH2gzHC_U?feature=share

Did it sound like this? This is on my n43 when accelerating

[Tambohamilton]

Heat shields. Mine had a dented heat shield which buzzed against the prop shaft bearing housing at certain RPMs. A quick bend and it stopped completely. So glad I found that rattle. Just another 99 to go...

[jjmmarr]

Did you end up solving the issue?