The VANOS Oil Supply Line is high on the list of things to consider. You absolutely should disconnect the VANOS line at both ends, which requires you replace the 4 copper washers (2 at each end). If you remove one end and force the line out of the way, it can break the seal in the crimped fittings at the other end and this will result in the line leaking. If you can twist the banjo bolt fittings where they are crimped to the hose, then you must replace the hose.