This service bulletin provides information on some vehicles that may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
full bulletin at NHTSA ↗2008 Pontiac G8 powertrain problems
moderate 7 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
No new NHTSA powertrain complaint has been filed on this vehicle in over 11 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin provides information on the harmful effects of water or ethylene glycol in transmission fluid.
full bulletin at NHTSA ↗This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
full bulletin at NHTSA ↗This PI bulletin advises the technician on the proper way to install the pistons in an engine.
full bulletin at NHTSA ↗This bulletin advises the technician that the 6L50 (MYB), 6L80 (MYC) and 6L90 (MYD) Transmission Oil Filter and Seal Kit part number 24236933 is currently transitioning from a kit to the filter (24236517) and seal (24225347) being sold individually.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 1 most recent
Tl* the contact owns a 2008 Pontiac g8. While parking, the vehicle rolled backwards. The contact applied the emergency brake in order to stop the vehicle. The contact shut off the vehicle and it failed to restart. The vehicle was towed to a dealer who diagnosed that the transmission shift cable needed to be replaced. The vehicle was repaired, but the failure recurred. The manufacturer was…
Common questions
How serious is the powertrain problem on the 2008 Pontiac G8?
It's a documented issue but not catastrophic. 7 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Based on the 7 complaints filed, powertrain issues most often appear around 12,625 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.