The car: 2002 540iT with 75K miles. I have noticed with increasing severity that my engine has a surge of power at 3500-4000 RPM, most noticeable under full throttle. The power is reasonable at the lower RPM level but upon reaching a certain threshhold, there is a tremendous surge of extra power. The car idles perfectly and accelerates from zero (accelerator pedal floored) typically without the annoying surging. It seems to be more noticeable when mashing the accel pedal in a higher gear--the car would downshift normally and once advancing through the RPM range, the power surge would manifest itself. I don't know if this has any bearing, but a couple of years ago when I was doing some weekly commuting on a long stretch of smooth interstate, I was able to routinely see 120+ mph. After a few weeks of this driving, the surging problem, which was much less obvious then, totally disappeared. Any suggestions regarding this current issue would be appreciated.