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      11-09-2018, 07:38 PM   #1
jandref321's Avatar

Drives: 2012 X5M
Join Date: May 2014
Location: United States

iTrader: (1)

X5M Boost Leak Problems


I've been slaving away for the past six months trying to find a solution to my boost leak codes but have failed miserably.

30FF: Boost Pressure control, Boost Pressure Too Low Fault
310B: Boost Pressure Control 2, Plausibility Fault
3108: Boost Pressure Control 2, Leakage Fault

Conditions: 3-5 gear, 60-80 mph or 110mph, Exactly 14 or 16 PSI, JB4 on or off.

They started in April. I am running Velos stage 2+ and JB4. I had the JB4 installed and running for a month before this started. Since then I have completed the following:

-Turbos and wastegates rebuilt
-All Vacuum Lines Replaced
-Both boost solenoids replaced
-Replaced TMAPs
-Replaced all charge pipe hoses and clamps (For the second time)
-Replaced Intake Manifold Vent lines and cross over line
-Vacuum Test of all vacuum lines, tanks, and wastegate actuators
-Attempted Pressure test but found a hole in my passenger intake elbow (BMW reinstalled the hose clamp backwards to avoid the DV+ and the clamp ate through the elbow) I have ordered a new elbow and used rubber cement/tape to hold it until the new one arrives.
-Took to an Indy shop and they politely asked me to leave and not come back.
-Checked JB4 wiring 3 times
-Checked DV valve resistance and energized with 9volt to hear clicking

I am also running Go Fast Bit's Diverter Valve upgrade. I thought maybe they were not operating properly so I went back to stock DV and found that I could barely build boost and felt like limp mode. I switched back to DV+ and I can build boost but it dumps and throws a code at 16psi like before.

The stock diverter valves worked perfectly fine before I upgraded them and the diaphragms are in excellent condition. The DV+ has a heavy spring that holds the piston closed even when the solenoids are open. The Spring only allows the piston to open when enough boost is applied.

Considering this I think that the diverter valve solenoids are:

1) Failing open, but not throwing code until DV+ spring opens
2) Opening as soon as the engine turns on, but not throwing code until DV+ spring opens
3) Being actuated open by the computer erroneously, but not throwing code until DV+ spring opens

From some research and observation it seems that the DVs only open when energized and would fail closed. This leads me to believe that the issue could be software. Still leaving the other options open, and aside from the link to the DV, here are my thoughts on options:

1) Remove JB4
2) Replace DV solenoids
3) Replace Chargepipe
4) Replace Vacuum Pump

I have spent a behind load of money and time on this so far and not eager to keep working on it. JB4 with BCM is a PITA to remove/install on N63/S63. DV solenoids are like $60 each before shipping. Charge pipe is $450 or would need to spend a lot on a fabricator. Vacuum pump isn't that expensive but PITA to mess with.

Thoughts? Any extra tests you can think of?

2017 F30 330e CURRENT M Sport Package, M Performance Decals
2012 E70 X5M CURRENT Stg 1+ Turbos, DPs, Velos Stg 2+, JB4, Race Cats, Bavauto Coils
2011 F10 535i SOLD Burger Tuning JB4, BMS CAI
2003 E46 M3 SOLD aFe CAI, AP Axleback, SSK, H&R Springs, TMS CMBR Arms, PF RTABs

Last edited by jandref321; 11-09-2018 at 08:09 PM..