2008 X5 3.0si E70 - Camshaft actuator failure

[xchen]

I am helping a friend family with their 2008 X5 3.0si (I trust it is a E70 engine). The car has logged just over 90k miles. The engine light came up recently and I took it to a local AutoZone store. They helped reading the troubleshooting code out as P0012: Camshaft position - timing over-retarded bank 1. It also points to a camshaft actuator failure - mechanical timing condition. I was told that this X5 had an engine stall last week.

I am wondering if there is a DIY instruction sheet with photos for this repair. I need to know the location of this actuator to assess if I can handle the work. I do most routine maintenance and small repair work on my family cars but I am new to BMW.

About 3 weeks ago, the husband of my wife's friend family add 4 quarts of engine oil without knowing the oil level already in the engine. (I think this was done after the engine light came up.) A week ago the engine start to show unstable idle and I was called for help. I drained the engine oil and replaced oil and air filters. The drained engine oil took almost 3 1-gallon empty windshield washer bottles (2 filled to the cap and 1 to the full line). I then refilled with 7.5 quarts of full synthetic 5W-30 (Mobil Extended Performance) and the LCD display's Service Requirements Engine Oil Level shows close to the MAX line. I took the X5 for a 4-mile drive yesterday to the local AutoZone store to read the engine diagnostic code. It runs fine over the short trip.


Please advise.