Still no reply from anyone regarding my noisy car engine. When I start the engine, the noise is loudest near the driver's door side like its coming from the back of the engine. Its noisier when cold. Sounds like the mechanicals are loose towards the back of the engine and creating unnecessary noises. Can this be due to lifters, valves, camshaft, main bearings, timing chain going bad or what???? Other C180s do not sound so bad, but the high mileage ones do sound something like mine. Was there any change in the engine parts done after 1994 or improvements made to quieten the engine??? It really doesn't sound like a luxury or entry level luxury car. Even the Japanese and Korean cars do sound better and quieter. One thing is when I rev the engine either in N or D(car moving), the exhaust and engine revving noise is also quite loud and sounds like something is wrong, but everything goes ok, starts on first turn. Also no excess metallic or other bits in the oilpan. Can the exhaust noise be caused by valves staying open or what? Anyone out there please help solve this strange behavior.