I have recently put a 9 row oil cooler onto my escort cosworth. I put the sandwich plate on the end of the arm between the filter. Now sometimes when starting the car the oil pressure takes a wee while to build up and the engine is knocking. Once the pressure is up its fine. I've noticed that it must be the oil cooler draining back into the sump as the oil level is rising above the normal mark and it must be the extra oil from the cooler and pipework......any ideas?don't want to feck my engine!