My 550XP has an engine noise (very loud rattling sound) starting at approx 4900 rpm. The engine has to be warmed up before noise is noticable. Souds like it comes from upper part of engine. Dealer says this is normal, can't believe that as it is annoying to say the least. Any one else have this condition?

 

Im having the same issue, and I notice mine when the rpm's are up high or when Im driving at a higher speed. I was told to check the gasket at the manifold and y-pipe. If I get down and nail the throttle and watch the y-pipe once it starts to move then I hear the sound, so later today Im going to replace that gasket. Ill let ya know how I make out.

 

Thanks, that could be it as the engine runs perfect and does not make the noise until warmed up. Please keep me posted. I still have at dealer and will mention the above. Larrygan