[therealm3]

Hell all,

I wanted to reach out and see if other have this issue with their B58. Mine started doing it about 9 months ago and the dealer reprogrammed the whole car and Ecu and said it was fixed. It wasn't. I took it back and they replaced the valvetronic motor and said it was fixed. Surprise, it wasn't. Well then Covid hit and didn't drive much at all till a few months ago and was annoyed by the sound enough to take it back. They confirmed the sound but couldn't figure out what to do. Opened a ticket with bmw and they said to reprogram the ecu again and that would do it. I told them to really test the car before the all clear and they allegedly did. A week and a half after dropping it off, I drove it home. The excitement to be back in my car and was immediately let down when I pulled into the garage. Turned off the motor and heard the sound immediately. It varies in length after a drive cycle but it's somewhere in the one minute range. The frequency of the buzz sound can be faster or slower but I can't seem to correlate why.

So, do any of you have this sound and if you do, were you able to get any sort of fix from bmw?

Here is a short clip from under hood with the cover off the top of the motor:

And here is one from outside the car:

Really appreciate any input folks have.

Thanks!

[kern417]

maybe noisy water pump?

[therealm3]

Originally Posted by kern417

maybe noisy water pump?

I suggested that and they keep saying it's the valvetronic motor. To me it makes sense that it could be the water pump given when the noise occurs. I am just hopeful someone on the board has experienced this and can offer some insight. I found one guy on YouTube who posted a video of the same noise last year but he hasn't responded to my inquiry.

[weehe126]

The water pump is mechanical, not electric on B58s I thought. So there isn't a way it would keep spinning with the engine off. They probably keep saying it's eccentric shaft/servomotor related because this was an issue with N55s. Did they just replace the servo motor or also the eccentric shaft?

[440MIA]

Originally Posted by weehe126

The water pump is mechanical, not electric on B58s I thought. So there isn't a way it would keep spinning with the engine off. They probably keep saying it's eccentric shaft/servomotor related because this was an issue with N55s. Did they just replace the servo motor or also the eccentric shaft?

The B58 has 3 water pumps (that I know of). One of them is mechanical and the other two are electrical pumps. One of the electrical pumps is for the charged air to water cooler intercooler in our intake plenum. The second electrical pump is for cooling the turbo. Also, if you get the turbo hot enough and turn off the car, the turbo pump will stay on to cool it down.

[weehe126]

Originally Posted by 440MIA

The B58 has 3 water pumps (that I know of). One of them is mechanical and the other two are electrical pumps. One of the electrical pumps is for the charged air to water cooler intercooler in our intake plenum. The second electrical pump is for cooling the turbo. Also, if you get the turbo hot enough and turn off the car, the turbo pump will stay on to cool it down.

Nice, makes sense. Then would make sense it could be the turbo cooling pump since it's only after shutdown. The servomotor issue would occur before start up (waking the car up), and after locking the car (going to sleep).

[therealm3]

This is really good info. Thank you!

[therealm3]

Updating this thread with a solution.

For those that run into the same noise and the valvetronic motor and/or DME reprogram don't solve the issue (like me); then the fix is to replace the eccentric shaft. BMW stepped up for me and covered everything! Car has been solid since the repair. no noises at unlock or when I shut it down. Plus I seem to have less of the mid throttle dead spots in the power band like I used to. Very happy they finally got it solved. It took a fair amount of time at the dealer and I had to stand my ground each time they returned the car and i still had the noise. Having a cool service advisor helped for sure too.

[john_f30]

I'm having the same issue. Valvetronic motor was replaced. Got my car back last week thought was fixed but then couple days ago it started buzzing again. I'm going to ask my SA have them check the eccentric shaft. Thanks!

[Supr3me]

Just noticed this sound the other day. As far as I can tell it's only done it the once so far.
I'm 60K miles, out of warranty and heavily modded. Recommend proactive replacement now or monitor and replace later? Will the frequency of the sound at shutoff likely increase over time in a linear fashion?

[therealm3]

Originally Posted by john_f30

I'm having the same issue. Valvetronic motor was replaced. Got my car back last week thought was fixed but then couple days ago it started buzzing again. I'm going to ask my SA have them check the eccentric shaft. Thanks!

No problem! Hope it works out.

[therealm3]

Originally Posted by Supr3me

Just noticed this sound the other day. As far as I can tell it's only done it the once so far.
I'm 60K miles, out of warranty and heavily modded. Recommend proactive replacement now or monitor and replace later? Will the frequency of the sound at shutoff likely increase over time in a linear fashion?

Mine was happening most of the time when I unlocked the car and every time I shut it down. Length of the drive cycle and higher ambient temperatures made it more pronounced. (Longer duration, higher frequency of the buzz/knock, and volume of the sound.) So, long story short, it was worst in the summer. If yours barely does it now, you might want to wait, cause I'm reading through the parts list and report from the mechanic again, and it sounds like a pretty big job. But if you have a good independent or friend, maybe it won't be too bad. Hopefully that helps.

[weehe126]

Originally Posted by 340i6mt

Did anyone ever find a solution to this noise? Experiencing this with 16 340i

Eccentric shaft motor.

[G.Newt]

Originally Posted by weehe126

Eccentric shaft motor.

All the ones I've seen on here, including myself, the eccentric shaft itself needed to be replaced as well. I hope whoever else has this issue, just the valvetronic servomotor needs to be replaced. But the handful of us haven't been so lucky

If you're like me and use a shop, it almost makes sense to replace both, since you'd be paying double the labor to go back in and replace the shaft in case the servomotor didn't completely fix the issue.