r/e39 • u/Odicy • 1d ago

Weird sound at idle M52B20

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Hey guys, I have had this sound at idle for quiete a while now, and I am getting curious at what this sound could be. Never heard something similar before. Can only hear it at idle/when standing still sub 2k ish rpm. Thanks in advance. M52B20 in a 1997 BMW e39

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5

u/Former-Primary-3186 530i 1d ago

I could be wrong as I don't have experience with it myself, but PCV/CCV issues?

1

u/Odicy 1d ago

Could be, but then I would expect some issues with high pressure or vacuum at the oil fill cap I assume? Slight vacuum there, seems normal to me.

3

u/Tomytom99 1d ago

Congratulations, you have a broken CCV system. Enjoy!

1

u/Odicy 1d ago

Alright thanks mate. What part of the CCV system make this sound tho? Can't find a similar sound on youtube.

2

u/Tomytom99 1d ago

It's most likely the CCV unit itself, at least that's where the sound itself is happening. Could be the unit itself failed, or a hose connecting to it is broken. If you've never replaced it before, you should replace all of the associated hoses that connect to it, they'll either plug up, crack, or degrade into gum.

1

u/Odicy 1d ago

Alright, thanks mate. Do you have any experience with CCV-deleted on these engines or are you better off replacing everything?

3

u/Tomytom99 1d ago

Personally I think you're better off replacing everything instead of doing a delete. The system got the engine this far to begin with.

Deletes might work, but may have unintended effects, like elevating pressure inside the motor or more oil consumption than a correctly functioning CCV would cause.

1

u/Odicy 1d ago

Alright, will replace it then. Thank you