I had my water expansion tank replaced, two weeks later the CEL lit and had the Porsche Dealership service the car, their code findings were cylinder 1-3-5 not working. Causes could be cooling leak into them.
The car started and ran fine until engine temp. reached 180 degree then it started to idle rough plus the CEL lit & stay on while driving. The car do not burn or smoke from pipes at start-up or while idling.
Any ideas what could causing this problem, I appreciate any info of a possible solution.