12 Jan 2011 X5 Boost Pressure Faults
A problem we are seeing more and more on the 6 cylinder twin power turbo N55 motors is faults on the X5 Boost Pressure control. The fault code can stem from a few sources, especially if customers modify their vehicles for more power. Even on vehicles with a lot of aftermarket performance parts, this fault almost always means either there is a boost leak, or mechanical problem with the boost control solenoid.
This 2011 BMW X5 came in with fault code 2c57, Charge-Air Pressure Control Lower Value Boost Pressure too low. Having experienced this many times in the past we instantly knew where to look; the boost control solenoid, on the middle of the motor, under the intake pipe on the passenger side of the engine. Tugging on the vacuum line made the issue clear, a split rubber hose was causing the control valve to not function correctly.
Replacing the section of hose should take care of the boost control fault, and return the system back to normal operation. A word of caution on vehicles that may have neglected to take care of this issue right away: The stress to the electronic valve from the engine computer trying to control a non-responsive solenoid, greatly shortens its life. We have repaired these hoses only to have them come back in a month later with the boost control solenoid valve dead. If you fixed the hose in time, and you don’t need the valve, count yourself lucky.
Do you have a reduced engine power message on the dash, or any boost performance problems or faults? Come in for a diagnosis before it costs you more! Make an appointment by calling us at 815-230-2900, or contact us through email at [email protected]. We’re conveniently located in the Naperville/Plainfield area of the Chicago Metropolitan suburbs.
Richard Hardowar
Posted at 10:59h, 12 OctoberHi Where did the hose you found crack came off form. Thanks
Richard.
fluidmotorunion
Posted at 16:18h, 19 OctoberThanks for the comment! The line goes to the wastegate on the turbo.
Maxwell O
Posted at 18:31h, 25 DecemberI have the same problem going in, 3100 and 2ABE, exhaust sound very weird at lower power and right after higher rpm. I think my boost selenoid or pressure converters are not working. i replaced the map sensor , turbo charger and still problem there, every time i make an attemp to boost, it goes into reduced power. please help. I am currently going to replace the pressure converter and see if it will solve the problem for me, i can reached at [email protected]
fluidmotorunion
Posted at 08:44h, 30 Decemberplease try that and email [email protected]
JImA
Posted at 12:52h, 22 JanuaryThanks for this!
I found that the crossover tube seemed loose on the driver’s side where it plugs in low. I added a vacuum hose clip. In taking off the large air pipe (running along the passenger side of the engine which covers the boost solenoid) between the air filter box and the connection to the inlet of the turbo charger, the corrugated plastic tube “crankcase breather pipe” which goes from the valve cover to the air pipe had a crack and when removed disintigrated in my hands.
Pending delivery of a new breather “tube”, which includes some kind of sensor, I carefully removed the corrugated plastic part of this assembly and replaced with a section of 3/4″ heater hose. Codes haven’t come back.
fluidmotorunion
Posted at 14:21h, 24 JanuaryThat’s great to hear! Good Luck!