[honerboys]

i'd first make absolutely sure you have the timing marks lined up correctly - you could be tapping the pistons against the valves - if the marks are on then i'd look at that #1 cylinder - who knows what might have fallen down that open injector port and got through the open valve - might not be metal so magnet won't find it - find one of those scopes that you can send down the spark plug hole and have a look inside the cylinders - some car parts stores will lend them to you here in the u.s. - and as tdskip said keep adding a bit of oil to cylinders - might dissolve some accumulated junk - and i think you can just route the oil cooler line back into itself to bypass the cooler