Insufficient Oil Pressure Supply Causes BMW Issue
The “Service Engine Soon” may illuminate and engine power is reduced on a 2008-2010 BMW vehicle. This can occur after driving for some time with the engine at full operating temperature. If the ignition is cycled, the engine may then perform normally.
The following faults may be stored in the DME:
2A82 VANOS intake...stiff, jammed mechanically
2A87 VANOS exhaust...stiff, jammed mechanically
130108 VANOS intake...control fault, a position not reached
130308 VANOS exhaust...control fault, a position not reached
Note: VANOS is the BMW term for its variable cam timing system. For the N54 engine, the following secondary faults may be stored:
120408....charge-air pressure control, cut-out: Boost pressure accumulation blocked
3100...Boost pressure control deactivation, boost pressure buildup prohibited
The VANOS faults can be caused by an insufficient oil pressure supply to the inlet VANOS adjustment unit. To effectively move the camshafts to the target positions in the specified time and under all engine conditions, sufficient oil pressure supply to the VANOS control pistons must always be available. If engine operation requires the VANOS system to quickly advance or retard the intake or exhaust camshaft, faults may be stored if the camshaft is “late” or does not reach the target position. In this situation, engine power may be reduced and a check control message is displayed. The consequential fault 3100 or 120408 can also be set in the DME fault memory as well.
Perform all applicable test plans completely for the faults stored. A mechanical restriction or electrical failure of the VANOS solenoid and/or the electrical circuit can cause insufficient oil supply to the VANOS assemblies as well. If the completed test plans results are inconclusive, proceed to Step 2.
The oil filter cap insert may have been inadvertently removed during the vehicle’s last oil service. If the insert is not installed, it will result in non-filtered engine oil being supplied to the engine, possibly clogging or damaging the VANOS solenoids. If the oil filter cap insert is found to be missing, the entire oil filter housing cap must be replaced.
Replace both VANOS solenoids, change the engine oil and filter, and reset the service data (when applicable). While performing the test plans for VANOS faults, an inspection of the camshaft hook ring seals is advised. Inspect for worn camshaft bearing ledges. If needed, replace only the bearing ledge and rectangular hook rings for the affected camshaft. Do not replace the camshaft(s).
1) Camshaft bearing ledge; 2) Intake camshaft; 3) Hook ring seals.