[335D M57] Please help narrow down

wannaseemdead · 12-02-2025, 04:39 AM

Hi, I have the famous no boost on small turbo issue with my m57.

The problem is - I have no idea what could be causing it, because the turbos, pressure converters, vacuum lines and vacuum canister are new (2 years old). The pressure converters are OEM.

I looked at the wastegate as I thought maybe it is stuck open but no - the wastegate closes at idle, but I still get no boost (or barely feel any) from the small turbo. The vacuum escapes as expected when the car is shut off, indicating that the wastegate is working properly.

Could someone please help me narrow this down, because most of the common culprits have already been replaced.

wannaseemdead · 12-04-2025, 06:47 AM

Can someone please help? I'm still having this issue, it's gone from being intermittent to consistent. The rod for the wastegate closes when the car is on, and I can feel slight amount of boost, though it never builds up - it feels like it's stuck at a point and doesn't build boost until it switches to the big turbo.

Looking at this diagram below for my car (2006 m57 EU), part number 4 labelled 'electric valve' looks like it could be the culprit and so I ordered the part.

In the mean time, I wanted to see if anyone had similar issues, and whether this valve could indeed be causing my issue? It's worth noting that the car is EGR disabled, not removed.

12-02-2025, 04:39 AM	#1
wannaseemdead New Member 2 Rep 25 Posts Drives: BMW 335d E92 Join Date: Feb 2022 Location: Isle of Man iTrader: (0)	[335D M57] Please help narrow down Hi, I have the famous no boost on small turbo issue with my m57. The problem is - I have no idea what could be causing it, because the turbos, pressure converters, vacuum lines and vacuum canister are new (2 years old). The pressure converters are OEM. I looked at the wastegate as I thought maybe it is stuck open but no - the wastegate closes at idle, but I still get no boost (or barely feel any) from the small turbo. The vacuum escapes as expected when the car is shut off, indicating that the wastegate is working properly. Could someone please help me narrow this down, because most of the common culprits have already been replaced.
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12-04-2025, 06:47 AM	#2
wannaseemdead New Member 2 Rep 25 Posts Drives: BMW 335d E92 Join Date: Feb 2022 Location: Isle of Man iTrader: (0)	Can someone please help? I'm still having this issue, it's gone from being intermittent to consistent. The rod for the wastegate closes when the car is on, and I can feel slight amount of boost, though it never builds up - it feels like it's stuck at a point and doesn't build boost until it switches to the big turbo. Looking at this diagram below for my car (2006 m57 EU), part number 4 labelled 'electric valve' looks like it could be the culprit and so I ordered the part. In the mean time, I wanted to see if anyone had similar issues, and whether this valve could indeed be causing my issue? It's worth noting that the car is EGR disabled, not removed.
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