I have a 2004 325i (E46) w/auto transmission - when I lost power steering over a year ago, I replaced the original p/s pump with a LUK-30 unit (& new reservoir/filter), whereupon it immediately developed a "lock-up" condition when cold (the colder it is, the worse it is, while in summer it disappears). When cold, upon first starting the car, the p/s makes a slightly different whine and has no boost until you rev up the engine while turning the wheel sharply to "break" it loose, then all is normal and the whine disappears. (Note: I flushed the p/s system by pouring new fluid into the original reservoir/filter while allowing return line to drain into a pan for disposal *before* installing the new reservoir/filter and refilling with proper fluid. Does this sound like a "new/rebuilt" pump issue, an old/delaminated hose issue, or a gunk-trapped-somewhere-in-the system issue - or what? Thanks in advance?