M57 question

[helix402]

I must have been bored and wearing a BMW anorak (I do own one). I have noticed the later M57 engines have a different pipe from the turbo to air mass meter.

It has a small fan at the turbo end. Does anyone know the purpose of this? I have seen it has failed on some cars and caused turbo failure.

[BFleming]

I think it's an air diffuser rather than a fan. Completely pointless in my opinion, but I can see that if it broke (following years of heat-hardening) it would hit the turbo & lunch it. Remove!
By the way, it's a pipe from the MAF to the turbo, not the other way round!

[helix402]

BFleming said:

I think it's an air diffuser rather than a fan. Completely pointless in my opinion, but I can see that if it broke (following years of heat-hardening) it would hit the turbo & lunch it. Remove!

You’re right. It’s not a fan. I don’t have one on my car and as you say-failure would be detrimental to turbo longevity.