01 x5 losing power on cruise

[ajaxoftherockies]

Hi Gang,
Here's what I've experienced: 2001 X5 (E53) runs fine while accelerating and going uphill. Coasting or downhill, I don't notice any roughness or anything out of the normal.

When on level ground, cruising, with the throttle is in a neutral position - not accelerating or decelerating - the engine, after a few seconds, will lose power; just drop out as if I released the throttle. If I hold the throttle there, power will come back after a few seconds then drop out again.

If I accelerate while the power is gone, it comes right back and all is good, as long as I'm accelerating.

Also noticed that the MPG gauge (i.e. vacuum) goes full max when the power drops out (I'm talking about engine power; there is no electrical element I can see). And, the drop-out happens while the vacuum is between 20 and 40mpg for more than 10 seconds or so.

I'm suspecting the MAF, but would appreciate some more input before I drop a triple-C note.

Thoughts anyone?

THX!!!

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