[Spitfire007]

2009 328i 6MT.
98500 miles.
Car runs well. No CEL.

Just an odd rattle that seems to coincide with throttle pressure. Very light throttle, maintaining speed, I can hear a gentle rattle under the hood. Punch it and it seems to go away, returns under part throttle.
Sounds a little like raspy lifter noise? Hard to capture on video, it's too faint still.
Some days are worse than others.
Car has 3 stage IM and BPC tune.

Any ideas?

[Zaíne92]

Same issues. Following

[Phyrexia]

Does it do it while the car is out of gear? A buddy with a right foot and a mechanic's stethoscope would help you narrow down the location of the rattle.

[Spitfire007]

Originally Posted by Phyrexia

Does it do it while the car is out of gear? A buddy with a right foot and a mechanic's stethoscope would help you narrow down the location of the rattle.

Not audible when at idle.
It's throttle dependent under slight or no load when driving very lightly. As soon as I lift my foot, sound disappears.

[gunnerxq]

Originally Posted by Spitfire007

Not audible when at idle.
It's throttle dependent under slight or no load when driving very lightly. As soon as I lift my foot, sound disappears.

I think it's related to our infamous tick. It comes and goes in my car like the tick. Had the car since 58k miles now it's at 140k.
It's more apparent in the summer.

[squaredphoto]

Got a video of the sound?

A little weird, but you can take a stethoscope, take off the part that does the listening, and place the tube onto different parts of the engine while someone is applying light throttle.

[desertman123]

Originally Posted by squaredphoto

Got a video of the sound?

A little weird, but you can take a stethoscope, take off the part that does the listening, and place the tube onto different parts of the engine while someone is applying light throttle.

A long screwdriver works as well

Spin each pulley by hand too. The alternator, PS and AC will feel weird, but should not grind. (You're feeling their clutches/hubs/internals spin around instead of just a pulley on a bearing)

Also I'd just take the cabin air filter cowl off, engine cover off and just start grabbing stuff and see if anything is loose, brackets, wire harnesses, etc. Maybe it's the cover itself??

[Spitfire007]

Originally Posted by squaredphoto

Got a video of the sound?

A little weird, but you can take a stethoscope, take off the part that does the listening, and place the tube onto different parts of the engine while someone is applying light throttle.

It's not loud enough. And only does it when driving.

[juld0zer]

Change your engine oil, replace the filter with a Mann or genuine filter, clean your VANOS solenoids and the check valves. Reset adaptations and monitor.

On my early N52, I have narrowed it down to a clacking noise from the VANOS adjusters. There is a couple of threads about a pinging type noise upon re-engaging the clutch when upshifting. On mine it does come and go, and does sound exactly like pinging. It is very brief and never logs a fault. This may be the reason the later N52 changed to a variable displacement oil pump - there are hints of this in the BMW document.

Yours is a later N52 - was it part of the VANOS adjuster recall?

[Spitfire007]

Originally Posted by juld0zer

Change your engine oil, replace the filter with a Mann or genuine filter, clean your VANOS solenoids and the check valves. Reset adaptations and monitor.

On my early N52, I have narrowed it down to a clacking noise from the VANOS adjusters. There is a couple of threads about a pinging type noise upon re-engaging the clutch when upshifting. On mine it does come and go, and does sound exactly like pinging. It is very brief and never logs a fault. This may be the reason the later N52 changed to a variable displacement oil pump - there are hints of this in the BMW document.

Yours is a later N52 - was it part of the VANOS adjuster recall?

It's due for an oil change, but regardless it's been doing it for over a year.
Have not gotten any notice regarding Vanos recall.
I don't cheap out on oil changes or filters and have them done by Dealer or reputable Indy.
Don't know about resetting adaptations. Car's a manual, there's not much to reset as I understand it.

[lowrydr310]

Originally Posted by Spitfire007

2009 328i 6MT.
98500 miles.
Car runs well. No CEL.

Just an odd rattle that seems to coincide with throttle pressure. Very light throttle, maintaining speed, I can hear a gentle rattle under the hood. Punch it and it seems to go away, returns under part throttle.
Any ideas?

I have the same issues but it's intermittent. It happens more often that not, and like you said it's only at very light throttle applciations while maintaining speed, sounding like pinging (detonation??) when the engine is lugging. Downshifting makes it go away, likewise if I drive around in DS (I have an automatic) it rides in a lower gear at higher RPMs and I don't ever hear it.

[juld0zer]

The adaptations I am referring to are the DME adaptations. It makes a huge difference.

Try what I suggested and report back.

[rothwem]

Originally Posted by Spitfire007

2009 328i 6MT.
98500 miles.
Car runs well. No CEL.

Just an odd rattle that seems to coincide with throttle pressure. Very light throttle, maintaining speed, I can hear a gentle rattle under the hood. Punch it and it seems to go away, returns under part throttle.
Sounds a little like raspy lifter noise? Hard to capture on video, it's too faint still.
Some days are worse than others.
Car has 3 stage IM and BPC tune.

Any ideas?

I've heard of the DISA flaps coming loose, I wonder if that's the issue? No idea how easy they are to pull and check though.

[Spitfire007]

Originally Posted by juld0zer

The adaptations I am referring to are the DME adaptations. It makes a huge difference.

Try what I suggested and report back.

Do you have a way of doing this?
I have a tune for the 3 stage IM. Would this interfere?

[Spitfire007]

Originally Posted by rothwem

I've heard of the DISA flaps coming loose, I wonder if that's the issue? No idea how easy they are to pull and check though.

I sure hope not!
If it comes apart, pieces would go right into the cylinders....
I think you have to pull the manifold off to then remove the valves.

[juld0zer]

Originally Posted by Spitfire007

Do you have a way of doing this?
I have a tune for the 3 stage IM. Would this interfere?

I have access to ISTA and INPA. I believe INPA can do it too but i have always done it in ISTA.

I highly recommend you remove and inspect the checkvalves also.

[juld0zer]

Originally Posted by Spitfire007

I sure hope not!
If it comes apart, pieces would go right into the cylinders....
I think you have to pull the manifold off to then remove the valves.

The manifold has plenty of U bends to trap large parts. Parts of the seal will most likely just go out as smoke

The small valve requires removal of the manifold or at least have it unmounted and off the head

[Spitfire007]

Car going for oil change tomorrow as well as full inspection and investigation into "the noise".

They stayed over the phone it may just be low on oil, but the level still does ok...we will see.

[Spitfire007]

UPDATE

Didn't find anything. Noise wasn't loud or obnoxious enough. Said it might just be a slightly loose heat shield or exhaust rattle.

Valve issues would be indicated by significant drive ability issues, of which I have none so far.

Noise is worse when cold however.

[BalkanAvenger]

Mine ended up being blown out cat/cats. Can you watch this video and let me know if it's the same as mine?
5:00 minute mark.

[Spitfire007]

Somewhat similar. But I do not hear mine at either idle or when revving. Only when driving.
If cats went bad, I'd just get a set of AA headers and hope I can pass emissions in PA.

I bet the car would scream once I update the tune to include headers!

But for now, it's too quiet and Only loud on cold starts.

[E90_slides]

did you ever figure out what it was? I have the exact same issue. the first inch of throttle between 2k-3k rpm I hear what sounds like chain slap, but once I add more load to the engine it goes right away and comes back when I release the pedal and pass the same spot. I can coast and hold the pedal and hear it constantly but as soon as I go past that point it goes away. It gets a lot quieter after 10 minutes of driving but I can still barely hear it. changed my oil, did a full engine flush, took off the accessory belt and drove but the noise is still there, so that means it's internal. took out my valvetronic motor and inspected. there is some wear on the spindle and on the gear inside the valvecover. maybe I didn't seat it right when I replaced the valve cover gasket last time and it damaged that gear or something? can barely hear it at idle when I rev it up but since there's no load on the engine its barely audible but if I feather the throttle quickly between 2k-3k rpm you can hear it better at the beginning of each feather of the throttle. my friend was under the hood when I tried this and he said its definitely coming from the top of the engine and not the front(timing chain) or the bottom(exhaust). When I replaced my valvetronice motor it went away, but I got and engine code for accidentally taking off my maf and forgot to replug it in, but I didn't notice and thought I messed up the Valvetronic motor so I took out the valvetronic motor and replaced/relearned end stops but now the noise is back and can't seem to get the noise to go away even by replacing Valvetronic motor and relearning the end stops again. I'm at a loss.