choi jong du

addm278 engine
First time seeing a problem...

When you step on the brake, the turbo westgate moves

Same problem occurred when testing the same vehicle


Problem at 23 seconds of attachment video

Is this problem normal?

If this symptom repeats, it seems that one day there may be a Westgate defect.

When the brake is not used, the Westgate does not move normally.

barryrobinson19

Doesn't the vacuum line from the wastegate lead to a box of some sort that controls the wastegate opening, via the ECU. Perhaps that is where the problem exists. I doubt the wastegate diaphragm is punctured. The diaphragms are pretty stout. I have not followed the vacuum line, just thinking out loud.

choi jong du

Thank you for answer.

Did you see the video I uploaded?

Test your car the same way I did. / Look at Westgate when you hit the brakes

Sltncls63

The problem is in Vacuum pump check Valve everybody keep your eye in this valve always it’s very common problem in M157 there is 2 valve 1 big and 1 small the small 1 is damage in your car remove the small pipe and unsecrew the small valve and replace it the problem is the valve didn’t hold the Air inside the vacuum pump





The dealer didn’t sell the check valve alone they sell all the vacuum pump but you didn’t need that you can find in ebay new check valve and fit this pump i replace same this check valve in my car same engine in your car this problem make your car slow and slow to increase the turbo boost

sambam2006

I have the same issue, did you ever resolve this issue?

My car does the exact same as yours in the video, everything works fine as usual.

I had the whole vacuum pump replaced by Mercedes and issue is still the same as your video.

It would be interesting to see if you got it resolved

san40

Also related: https://mbworld.org/forums/w212-amg/...ve-repair.html