Dealer says this is not a common problem - However BMW does have a service bulletin on the problem. In my case the "Service Engine Soon" light was illuminated and the fault codes indicated a problem with the VANOS. Luckily the vehicle was still under the new car warranty. The dealer performed the following service which resulted in better fuel mileage (from 28 - 34 hwy) and corrected the fault -------------------------------------------------------------------------------- Replaced CAM support bearing shell and rings - per sib as: Figure 1 - A mechanical restriction or an electri... Figure 2 - 1. Camshaft bearing ledge 2. Intake ... Figure 3 - Note the deep grooves worn into the in... Figure 4 - Acceptable camshaft bearing ledge - mi... Reduced Power Complaints On Some BMW Engines Equipped with VANOS Power Reduction, FC 2A82 Intake VANOS and/or FC 2A87 Exhaust VANOS Camshaft Faults are Stored in DME AFFECTED MODELS/ENGINES E82 and E88 (1 Series) with N51, N52K and N54 engines produced from 1/2008 E90 and E91 (3 Series) with N52 engine produced from 3/2005 through 6/ 2006 E90, E91, E92 and E93 (3 Series) with N51, N52K and N54 engines produced from 7/2006 E85 and E86 (Z4) with N52 engine produced from 1/2006 E83 (X3) with N52K engine produced from 9/2006 E60 and E61 (5 Series) with N52, N52K and N54 engines produced from 3/2005 E70 (X5) with N52K engine produced from 10/2006 E71 (X6) with N54 engine produced from 1/2008 SITUATION The "Service Engine Soon" (MIL) lamp is illuminated and a power reduction is clearly perceptible. This situation can occur after driving for some time with the engine already at full operating temperature. If the ignition is cycled, the engine then usually performs normally. The following faults are stored in the DME: 2A82 VANOS intake - stiff; jammed mechanically 2A87 VANOS exhaust - stiff; jammed mechanically 3100 Boost-pressure control, deactivation - boost-pressure buildup prohibited (N54 only) CAUSE The VANOS faults are 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. When the engine operation requires that the VANOS quickly advance or retard the intake or exhaust camshaft, fault 2A82 or 2A87 may be set 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 can also be set in the DME fault memory as well. 1. A mechanical restriction or an electrical failure of the VANOS solenoid and/or electrical circuit can cause insufficient oil supply to VANOS assemblies (Figure 1). 2. The oil filter cap insert may have been inadvertently removed during the vehicle's last oil service. If this insert is not installed, it will result in non-filtered engine oil being supplied to the engine, thus possibly clogging or damaging the VANOS solenoids (Figure 1). 3. If the oil filter cap is found intact, it is possible that the camshaft hook ring seals (3) have worn a groove into the camshaft bearing ledge (1), causing a drop in oil supply to the VANOS unit (Figure 2). • Note the deep grooves worn into the intake camshaft bearing ledge by the camshaft hook ring seals (Figure 3). • Acceptable camshaft bearing ledge - minor wear marks from the rotation of the camshaft are normal (Figure 4). PROCEDURE Perform all applicable test plans for the faults stored; replace parts as directed. If a root cause can be found, continue on to the following steps. If the oil filter cap insert is found to be missing, then the entire oil filter housing cap must be replaced. If excessive wear to the camshaft bearing ledge is found, it is only necessary to replace the camshaft hook ring seals and the affected camshaft bearing ledge. Refer to the appropriate service manual. Note: N51, N52 and N52K intake camshaft bearing ledges and hook ring seals cannot be replaced separately. __________________
