Greetings,

I have a 2012 Countryman S All4 I'm trying to figure out a boost issue on. Mods:

• Stock S turbo
  • Replaced last month along with oil supply and return lines. Turbo is a new unit from Borg Warner
• Catless downpipe
• M7 maxx flow air intake
• M7 air intake tube (air filter to turbo)
• M7 noise maker delete pipe
• M7 intercooler pipe (resonator delete pipe)
• Wagner upgraded intercooler
• Alta spring in stock DV valve
• Borla axle back exhaust
• M7 oil catch can

I have an issue where by the car either has very little boost (3-6 PSI) with the limp mode light, or the car pull incredibly hard and is hitting 20+ psi according to my Scangauge. When doing a 4th gear pull and I mash the throttle at 2500 RPM, the car pulls hard but surges and I can hear the DV valve opening and closing quickly. If I give the car just the right amount of throttle, I can get consistent boost up to red line, but its a very small pedal difference between steady boost and overboost and surging. I was thinking being that the car sometimes (can't figure out exact condition) lacks boost, that the replacement turbo might be bad in the wastegate or something of the like.

I have a Stage 2 tune coming soon along with NGK 1422 plugs. However I'm wondering if I'm in for another turbo replacement or perhaps a vacuum issue? I tested vacuum at the vacuum pump and I'm within spec of 26 hg off the pump and I'm not getting any deviation based codes. I do get 2C57, 2C91 and 2CB3 codes when the car has next to no boost and limp mode light comes on. Its frustrating as the car either is gutless or pulls hard to the point its surging. Any thoughts? I will try to post a video on the condition ASAP.

Thank you!

 

2C57 seems to be a boost leak code….
2C91 is for the diverter valve sticking open…
2CB3 is a wastegate actuation code…

I would start by removing the diverter valve and making sure it was out back together correctly after installing the Alta spring. Also, triple check the diaphragm for cracks or tears.

Also, 20 psi on stock tune? Something isn’t right with that either. Maybe some of your surging is related to the massive overboost. Stock boost should be between 12-15psi.

 

I agree. 20 psi (assuming Scangauge is close) isn't right. Going to check the wastegate length once I find a picture I saw once upon a time which showed the correct length. I think it was 150.5 mm or there abouts. I only checked the wastegate for slop, not length before installing. Hoping that is the issue as and I can adjust the gate if so.