Can anyone listen to this sound on the 540i

[bfrqrv]

Hi,

I wonder what this sound is, can you please listen? I have had the 540 since 2015 and in 9 years the sound has not changed, it remains exactly the same. The car has driven 30,000 km in those years. Oil is 5w40 and I Am thinking about 5w50, because the noise is completely gone when the engine is cold, so the first 15 minutes. Furthermore, the car runs nice and strong and on the dynamometer it still produces 310 hp. The sound does come from underneath the block I think and I recorded this with a telephone that I keep in the wheel arch, so it does have a sound box. In real life it sounds quite soft and its not sounding that serious, but when you record the sound it is a bit more present. What do you think, could this be the rod knock and how can I confirm this? If it is the rod knock <span class="Y2IQFc" lang="en">
https://www.blackshalo.com/noise.mp4is it necessary to repair this immediately?

[seagreen323i]

Sounds like vanos rattle to me.

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[bfrqrv]

Sounds like vanos rattle to me.

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Sorry for the few details on the car. Its 1997 without Vanos

[seagreen323i]

Hmm, well it definitely does not sound like rod knock to me. I'd say more timing chain oriented. Have you tried replacing the tensioner?

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[bfrqrv]

Hmm, well it definitely does not sound like rod knock to me. I'd say more timing chain oriented. Have you tried replacing the tensioner?

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Timing chain job (total action) is done a few years ago. This sound was there before the job and after the job, so the chance that it's coming from the chain is very small. My gut feeling says after 310000km the chance that it is the rod knock is quiet big. Also the fact that the first 10-15 minutes the sound is gone does fit in this. But on the other hand when you say it doesn't sound like rid knock, maybe there could be something else oil dependent out there what is responsible for this noise.

There must be a way to determine without taking everything apart, at least reasonable diagnose must be possible. Maybe when I use a stethoscope under the car brings some light.

Or maybe someone that has experience with the M62 rod knock and can confirm the sound.

[BimmerBreaker]

Sounds like lifter tick to me. Rod bearing knock would increase in relation to the revs (in frequency and volume) - and also, if it had rock knock for as long as you are describing, you would have ruined a crankshaft a long time ago. Rod knock is also quite loud - it is a pretty unmistakable sound... it's a knock sound. Yours sounds more like a tick. Tick is normal and not cause for concern, if the sound bothers you try a different oil weight.

[bfrqrv]

Sounds like lifter tick to me. Rod bearing knock would increase in relation to the revs (in frequency and volume) - and also, if it had rock knock for as long as you are describing, you would have ruined a crankshaft a long time ago. Rod knock is also quite loud - it is a pretty unmistakable sound... it's a knock sound. Yours sounds more like a tick. Tick is normal and not cause for concern, if the sound bothers you try a different oil weight.

Hmm Interesting. I know for sure its not a lifter because I know that sound form this engine, because when I leave the car alone for a few months there can be a lifter tick. I can "repair" that with the 3500rpm trick for a few minutes and when I use the car more daily the tick stays away.

This tick is very deeply and underneath the engine and rpm related. The only thing is that when you rev up the engine the engine sound is overruling the tick/knock sound, but when you listen closely in real time you can hear it goes up in frequency and then "disappears" I think due oil pressure its gone.

But ok, we are getting somewhere. I know that the real determine is difficult and even much more difficult remotely lol.Yes, I was thinking of 5w50 oil to have the oil a little thicker when it warms up, I think the tick will be better theoretically.
I wonder what can tick/knock underneath the M62 when we don't suspect piston slap, we know its not a lifter, we know that we have a good chain and tensioner and guides,we dont think its a rod knock and we know the oil pump bolts are not loose.

Maybe the best option is too leave it like it is and don't try to repair something that isn't broken. It didnt get louder the last 8 years and the engine is still as strong as 8 years ago. But somehow as a BMW fan you know the feeling!

[JimLev]

My 2 cents
Remove the fan after the engine is warmed up, you can hear the engine better without it, just don’t let it run for too long.
Check for an exhaust leak.

[bfrqrv]

My 2 cents
Remove the fan after the engine is warmed up, you can hear the engine better without it, just don’t let it run for too long.
Check for an exhaust leak.

I think the sound is exactly like this guy in this thread and the +200 rpm does help enormous. Your response here was about rod knock. My feeling says it must be that, but not that serious o maybe I can drive it further without doing the rod bearing job. The mileage is also in the range that it's almost impossible to have rod knocks you won't hear? Here is the thread from 2016

https://www.bimmerforums.com/forum/showthread.php?2282500-Rather-worrying-bottom-end-noise-normal-video

[bfrqrv]

I wonder are there members here that did the rod bearings on a M62 while there where not too late? I think I can do this myself, but when there is extra work besides replacing the bearings I can't.
Diagnosing is possible I guess when I open it up. It could be a very slight piston slap maybe its difficult to determine. I looked at the mileage when I bought the car. In 9 years I drove 30000 km and the noise is exact the same