[essjon]

Is this normal? Mine is making the same noise during cold start but It goes away after its warmed up.

[HighlandPete]

Originally Posted by fromwrxto330ci

Is this normal? Mine is making the same noise during cold start but It goes away after its warmed up.

Totally normal, it is the vacuum pump, exhausting into the engine cavity.

Was discussed recently for the N55 engine, not a new thing, other BMW engines do the same. For example, the M47/57 diesels were well known for the sound track, as the vacuum pump is very close to the oil filler cap.

[HighlandPete]

Here's the other topic.

http://f30.bimmerpost.com/forums/sho....php?t=1328263

[essjon]

Originally Posted by HighlandPete

Here's the other topic.

http://f30.bimmerpost.com/forums/sho....php?t=1328263

Thanks Pete!

[hawkjr1]

My 2013 535i had that tapping sound and the dealer end up replacing the HPFP and the pulley. It was louder in the morning when it first start. Good luck.

[essjon]

Originally Posted by hawkjr1

My 2013 535i had that tapping sound and the dealer end up replacing the HPFP and the pulley. It was louder in the morning when it first start. Good luck.

I thought yours sounded like this? Because mine totally sounds different

http://f10.5post.com/forums/showthre...highlight=HPFP

[HighlandPete]

Originally Posted by fromwrxto330ci

I thought yours sounded like this? Because mine totally sounds different

http://f10.5post.com/forums/showthre...highlight=HPFP

Yes different sound. The HPFP is external, the vacuum pump "quacking" is internal engine sound, with the oil filler cap off.

[808_F10]

I have a similar sound on start-up. The sound goes away when on the gas, for example, starting to pull out of the driveway. As soon as I let off the gas I can hear the sound again.

[M5 Monster]

what motor oils are you using ? how often do you change it ?

[essjon]

Originally Posted by M5 Monster

what motor oils are you using ? how often do you change it ?

BMW High Performance Full Synthetic 5W30 every 5k miles

[HighlandPete]

Originally Posted by fromwrxto330ci

BMW High Performance Full Synthetic 5W30 every 5k miles

Linking this to other engine sounds and the oil used, I'm sensing some posters are thinking it is something more sinister than the vacuum pump exhausting into the engine cavity.

Our vacuum pumps do exhaust internally. Think about it, if it wasn't into the engine, (remember it is lubricated by engine oil), we'd have a chirping sound track externally. At least with the oil filler cap fitted, there is limited sound to the outside.