My 1994 C180 Euro version has been making this noisy clack..clack..clack sound on acceleration from standstill. It sounds like something is very wrong in the engine or exhaust system. It lasts only a short time on acceleration, but becomes a real pain when everyone looks at you wondering if this Benz is for real or its going to blow up? Can it be loose valves, tappets, pistons, drive chain, bearings, whatever that can make such sounds like someone behind hitting a cardboard box very quickly. I haven't seen any thread on this strange problem. If you have some idea, please let me know what is required and how much it would cost to fix. Can I continue to drive this car or should I leave it at a workshop to fix this invisible problem? I just don't want to be SCALPED again!!!! Can it be the petrol ? The car has been at rest for the last 4 weeks at a paintshop.