Loping at slow speeds - E500

[pmay805]

I have an E500 with 97k miles. It had the plugs replaced at about 85k. But sometimes when I'm driving through the parking lot rather slowly it will lope, ie, jerky motions, speed then slow. I also notice that at stop lights it sometimes doesn't seem to run smoothly as I notice the RPM's seem to move up and down (it's around 600 or so). I guess there are probably a dozen or so things that could be causing this. Any suggestions?

thanks

 

[television]

This is a hard one MAF possibly

 

[BlackC55]

What year?

 

[pmay805]

e500 2003...the loping doesn't happen very often...it's sporadic. Could it have to do with the transmission changing gears?

 

[pmay805]

Thanks Malcolm, but what is MAF?

 

[Miffy]

or an Air Leak, sounds a bit like its hunting