my oil warning light came on suddenly whilst driving at 70mph on the M1. The car slowed down and appeared to lose some power and the engine became very very loud and rattly sounding. I was recovered by the AA who put a diagnostics machine on which said that there was a fault in cylinder 3 and appeared to be some oil leakage onto a rod below the engine. I took the car to a mechanic who has changed the oil pressure switch but this made no difference. He then advised me that I would be best getting a whole new engine put in as it could be a number of things. Having taken my car for a second opinion they said it could be the timing chain slipping a tooth that is causing my problems. At present the car starts and drives but is very loud and oil pressure warning light remains on permanently. I want to keep the car but don't want to spend hundreds on replacing engine when I could just get the same problem from a second hand engine. Is it likely to be timing chain or should I just cut my losses and sell the car?