[LukasJVW]

I recently bought a 08 335i that’s been modded a bit, and included is an Active BOV (maybe Autowerks). The car came with a MHD tuner but the previous owner had taken the tune off so it was factory ECU settings, and the BOV was very noticeable with making the noise. After a few weeks I flash tuned the Stage 2+ MHD tune, and now I don’t notice any blowoff period. Is it some issue with the BOV itself or would the tune have done something? What else could it possibly be? I’d like to start hearing it again.

[Bimmer_Bro]

Originally Posted by LukasJVW

I recently bought a 08 335i that’s been modded a bit, and included is an Active BOV (maybe Autowerks). The car came with a MHD tuner but the previous owner had taken the tune off so it was factory ECU settings, and the BOV was very noticeable with making the noise. After a few weeks I flash tuned the Stage 2+ MHD tune, and now I don’t notice any blowoff period. Is it some issue with the BOV itself or would the tune have done something? What else could it possibly be? I’d like to start hearing it again.

I would check the bov and the vacuum line coming off it. The bov is not controlled by the tune. It simply opens by vacuum when the pressure inside the charge pipe is different from the pressure inside the intake manifold (ie throttle body closes).

If the vaccuum line looks good at both ends then maybe take off the bov and see if it needs a clean and lube? I am personally not familiar with that bov.

[iqraceworks]

Originally Posted by Bimmer_Bro

I would check the bov and the vacuum line coming off it. The bov is not controlled by the tune. It simply opens by vacuum when the pressure inside the charge pipe is different from the pressure inside the intake manifold (ie throttle body closes).

If the vaccuum line looks good at both ends then maybe take off the bov and see if it needs a clean and lube? I am personally not familiar with that bov.

This right here.... Sounds like something isn't hooked up right.