I've got a '95 M6. The symptoms: If I gas it in the lower RPMS the car bucks. For example, Cruise control set on the interstate, going up hills the car bucks intermittently, about once or twice a second. Car pulls fine through the midrange, once it hits higher RPMS is maintains RPMS fine but something is definetly wrong and I'm pretty sure it's missing.

So far I've thought this was my opti, BUT the more I've been reading on here the less I'm sure. The car does this at all times, whether it's hot or cold. The opti has already been replaced, like less than 10k miles ago by previous owner. No hard starting issues, does not seem to idle rough.

Could this be my coil? Does this sound indiciative of 02 sensor? I don't want to spend the $ on an opti if that's not the case. TIA.

 

Yup, it feels like the engine is surging a bit.
Mine did the exact same thing and I replaced the plug wires and now the problem is gone.
T the time I had new OEM wires installed and I now have Elite OVC 9MM plug wires.

 

I should also add that when going through the upper RPMS it does occasionally skip a beat (obvious miss). Doesn't always do this. Doesn't seem to be at the same RPM each time either.

Supposedly the wires and plugs were changed at the same time or later as well. The car was supposed to have a tuneup shortly before I bought it (less than 10k miles ago)

It started this behavior shortly after I took it to the track (7 ***** to the wall passes within 2 hours)

 

Check ur Spark plugs and wires... i am having the same exact problem and my mechanic told me that its my plugs and this isnt the first time this happen...this is the cheaper option to go, if it still persists then it can be ur opti but i would do plugs and wires first

drew

 

like most people say, pop the hood when its dark out, look around the plugs and wires and see its arking or glowing around any of them

also check your coil wire.