Hi everyone!!!

I bought a Gray 08 G8 GT with 31,000 miles a few weeks ago. This is the frist car to impress me a lot since my first ride in a 87 turbo Regal. I've noticed some oddities with it and hope to find some answers/advice and maybe make some friends here. I feel a vibration/shudder light throttle. Like its lugging down. The trans shifts like you're pushing in a clutch. I wouldn't call it a flair. I plan on taking it back to the dealer but would like to try and know what I'm talking about. I don't think this is normal. Thanks for any imput.


http://i172.photobucket.com/albums/w14/paonecall/G8/Picture267.jpg



http://i172.photobucket.com/albums/w14/paonecall/G8/Picture268.jpg


Kurt

nice cars man !
I am getting mine tomorrow only a V6 but still looks bad ass.

Welcome to the forum!

Nice cars (both of them). My G8 had a similar sound at low RPM. I don't know if it was the DOD or what....

Nice car! Love the Buick... I had an 85 cutlass back in the day, similar body style, and even with it's 307 V8 it had NO power compared to that buick in your driveway!!

The lugging could be DOD enabling... next time you notice it, slide the shifter to the right (sport mode) and then hit it forward towards the "+" to engage the current gear in manual mode. DOD gets disabled in manual mode, so this is a good test to see if all of a sudden the lug goes away (if you tromp it from here, it will not auto-shift anymore, during this test, you can bump the shifter down "-" to get to a passing gear if you want to.

Alternatively, you can enable engineering mode on the DIC.

With the car OFF, press and hold in the rotating button on the left side of the steering wheel and crank the car. You will now see a big list of things on the center dic, using the same scroll wheel, scroll down about a page and a half to "AFM Mode" or something like that. When you're idling, it'll say "All active" (meaning v8 mode).... when you're lightly cruising in city or highway (less than 72mph or there abouts) when the ECM commands the DOD to be enabled, the DIC message will say "Half active". If that text corresponds to the "lug" that you're feeling, then it's safe to say "that's normal" ... the car is saving gas when you don't need all 361hp to maintain constant cruising speed.

Alternatives? Custom tune or Cortex can easily "disable" DOD/AFM which will allow you to run on all 8 cylinders all the time. In my car, this feels more responsive, alebit, at the cost of reduced gas mileage.

Hope this helps... be sure to tell us if this was the lugging, or if it was something else altogether!

--zepcom

Welcome!
Nice cars and have fun with your new G8!

Thanks everyone!!!

Zep, Thanks for the tutelage, You were right its the DOD. The shudder is gone in manual mode. Time for me to find a winter beater.


Kurt

Very nice, I miss my GN :(

Welcome! And there is a service bulletin out for vibration that includes new motor mounts to cure AFM vibration. Might be something to look into.

Welcome! Glad you've joined!