Sometimes you guys know more than the BMW techs ...
Posted: Sat Mar 28, 2009 1:51 pm
Several months ago I posted looking for advice when my R starting idling erratically. A number of you responded with the advice to replace the coil sticks. (If you don't know what they are, pull the spark plug wire off the plug; see that 5 inch or so plastic thingie that serves as a "boot" that fits over the plug tip? See the pict below. Yeah, that's it, that plastic thingie has a coil built into it).

Well, in addition to valve adjustments and TB syncs and new plugs and a new fuel filter that I didn't need and dropping lots of bucks with a BMW shop running "diagnostics" that "didn't indicate anything was wrong" and after swapping out each of my coils with a known good unit off an 1150RT ONE AT A TIME ...
I finally broke down and ordered a set of NEW sticks coils ($200. from Chicago BMW with their 20% discount). And, doncha know, once you replace BOTH coil sticks, your Boxer motor will be happy again - idle will return to normal, there will be no more surging at low speed/low rpm, and no more missing when the throttle is whacked open in higher gears. Just like you guys told me.
So, if your Boxer starts doing what mine did for months - erratic idle, missing under WOT in higher gears, like when you whack the throttle to pass in 4th or 5th gear, then surging and hesitating/missing once hot while crusing at low speed and low RPM's - don't hesitate and waste time on $70 an hour BMW techs who don't know jack *%#@. Do what I just did, and should have done months ago -replace BOTH coil sticks. Do that and you'll have one happy Boxer motor again.

Well, in addition to valve adjustments and TB syncs and new plugs and a new fuel filter that I didn't need and dropping lots of bucks with a BMW shop running "diagnostics" that "didn't indicate anything was wrong" and after swapping out each of my coils with a known good unit off an 1150RT ONE AT A TIME ...
I finally broke down and ordered a set of NEW sticks coils ($200. from Chicago BMW with their 20% discount). And, doncha know, once you replace BOTH coil sticks, your Boxer motor will be happy again - idle will return to normal, there will be no more surging at low speed/low rpm, and no more missing when the throttle is whacked open in higher gears. Just like you guys told me.
So, if your Boxer starts doing what mine did for months - erratic idle, missing under WOT in higher gears, like when you whack the throttle to pass in 4th or 5th gear, then surging and hesitating/missing once hot while crusing at low speed and low RPM's - don't hesitate and waste time on $70 an hour BMW techs who don't know jack *%#@. Do what I just did, and should have done months ago -replace BOTH coil sticks. Do that and you'll have one happy Boxer motor again.