I just recently got a 2003 X5 4.4 truck. The timing had been redone by the previous owner, but it would not stay in time. After taking the timing covers off and retiming it myself, I notice the passenger side intake cam would slightly get out of time with the exhaust cam (about an 1/8 of a turn). Would this be caused by a bad VANOS/Cam adjuster, a bad/stuck lifter, intake distribution piece, or something else? Thanks for your help in advance.