Minor vibration/shudder

[rlafash]

I am a fairly new owner of a 2008 G8 GT. I have noticed a rather minor vibration/shudder at low speed, low RPM. I placed the car in "Engineering Mode", section AFM, and determined that this very minor vibration/shudder only occurs at very low speed, very low RPM, when the AFM shows HALF CYLINDERS and a very low throttle demand, not enough to activate the other four cylinders, is requested. The vibration/shudder disappears when demand is sufficient to activate the other four cylinders. Is this considered "normal"? Thanks.

[BlueJacket]

Yes this is normal.

[-Ray-]

I don't think anyone has described it that well before. That's exactly what's happening.

[Chewy]

Yup! Put an exhaust on it and you can hear it too!

I kinda like it in a way... It's telling me I'm saving money...:loser:

If you don't like it, run it in the manual mode and it won't kick in or have a tuner shut it off.

[Blackdevil77]

I noticed this A LOT more with the most recent ECM tune. When you coast AFM almost immediately activates and when you push the gas again, you feel and hear that quick vibration which sounds almost like grinding. To me at least

[TomPierce]

Some tunes (in order to claim improved gas mileage) kick the AFM shut off up from "shut of at 6% throttle" to "shut off at 15% throttle".

(and you thought the tune was just more efficient)

:)

[rlafash]

To all who replied, thanks! Sometimes a "little assurance and pat on the head" is all that's needed.