Irecently bought a 1500 from local dealer he said it was repoed it had a water pump problem fixed that drove another 500 miles and it started ticking load took oof valve cover found it had broken =cam bridges then the timing in pieces replaced timing tensioners and passenger head did not replace oil pump what im wondering its running great but each stop its showing low oil pressure when i hit gas it goes right up thats why i didnt replace did i mess up should i have replaced or do i go back in and replace it?