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Did this for about a month, then it pegged it on motorway just before Sylvia Park for about 10 secs where we coasted then the the dash lit up like Xmas tree as the engine cranked up - whoa!. Hit the local Repco store - battery is dead- as so was replaced - sent to auto sparky for a lookover.
He didn't find anything from the OBD, other than a valve timing was out of whack (got that fixed).
It went ok for another 3 months and now its doing it again... sounds like alternator faulty or the cables to the battery are damaged (is a 2003 318Ti so the +/- box sits in the boot).
Any suggestions?