This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
full bulletin at NHTSA ↗2008 Pontiac G6 engine problems
moderate 16 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
16
Recalls
0
Avg fix
$3,100
What stands out
Among the 5 model years of Pontiac G6 in our records for engine problems, this one ranks #3 by owner-complaint volume.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine 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 identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
full bulletin at NHTSA ↗This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
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 technical bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Catalytic converter failure dominates the complaint set. Owners report failures between 87K and 142K miles with check engine light activation and loss of power. One paid $787 at a GM dealership for replacement at 90K miles; others declined repair due to cost. One owner disputes warranty coverage after a dealer initially claimed the converter wasn't covered, though the owner later learned coverage extended to 100K miles.
Intermittent stalling appears in multiple complaints. One owner documents stalling starting infrequently—once every few weeks during deceleration—and escalating to every few days, sometimes during acceleration. The dealership found no diagnostic codes and could not replicate the problem. In another case, the dealer pulled a cruise control code but made no repair.
Power loss and acceleration issues occur at various mileage points. Owners describe slow acceleration on the highway (taking excessive time to reach 55–65 mph), uncontrolled deceleration despite pressing the gas pedal, and in one case, complete power loss at 65 mph on the interstate tied to traction control activation. One owner at 60K miles reports this is "a dangerous defect."
Additional engine-related codes appear: an exhaust camshaft position sensor trouble code recurred seven times at 82K miles, and one owner documents P0300 (random misfire) with rough idle and engine noise. Dealership diagnostics often cannot isolate root causes.
Same Pontiac G6 engine reports on nearby years: 2005 · 2007 · 2009
Failure modes owners describe
Catalytic Converter Failure
Catalytic converter failure occurs prematurely, triggering check engine light and loss of power. Multiple owners report failures between 87K–142K miles. One owner had it replaced at 90K miles for $787 including labor; others report dealership diagnosis but no repair due to cost. Owners dispute warranty coverage—one states dealer claimed no coverage up to 100K miles, contradicting what appears to be standard emissions warranty.
When: 87K–142K miles
Symptoms owners cite: Check engine light illuminated; Loss of power while driving; Abnormal rattling noise from engine; Vehicle fails state emissions inspection
Codes mentioned: Check engine light (catalyst system failure implied)
Repairs/costs cited: Replacement cost $787 at GM dealership (2010); other owners declined repair due to cost
Recalls/TSBs owners mention: Dealer initially told one owner it was not covered under warranty; GM offered no assistance in other cases
Intermittent Stalling
Engine stalls intermittently while driving, sometimes during deceleration and sometimes during acceleration. Stalling frequency increases over time in reported cases. Vehicle restarts immediately after stalling. Dealership diagnostics find no trouble codes and cannot replicate the issue.
When: Starts infrequently, increases to every few days over 9 months
Symptoms owners cite: Engine stalls while driving at varying speeds; Stalling during deceleration (initial); Stalling during acceleration (later); Immediate restart after stall; No codes present in computer
Codes mentioned: None detected by dealership
Repairs/costs cited: Dealership unable to diagnose or repair; one case mentions cruise control TC code pulled from computer but issue unresolved
Power Loss and Acceleration Hesitation
Engine loses power under acceleration or maintains inadequate speed on highway. One owner reports slow acceleration to highway speed (55–65 mph) at 60K miles. Another reports uncontrolled deceleration despite depressing accelerator pedal. One case involved complete power loss at 65 mph on interstate tied to traction control activation. Diagnostic outcome varies—some cases resolve with catalytic converter replacement, others remain undiagnosed.
When: 60K–115K miles
Symptoms owners cite: Slow acceleration on highway; takes long time to reach 55–65 mph; Uncontrolled deceleration despite gas pedal input; Complete loss of engine power; Traction control light activation preceding power loss
Codes mentioned: Check engine light (in some cases)
Repairs/costs cited: One case resolved by catalytic converter replacement; others unresolved despite inspection
Exhaust Camshaft Position Sensor Trouble Code
Check engine light remains illuminated with trouble code related to exhaust camshaft position sensor detected during diagnostic testing. Recurred seven times while driving at low speed.
When: 82,350 miles
Symptoms owners cite: Check engine light illuminated repeatedly; Recurred seven times while driving 15 mph
Codes mentioned: Exhaust camshaft position sensor trouble code
Repairs/costs cited: Vehicle not repaired
Recalls/TSBs owners mention: Manufacturer not notified
Rough Engine Idle and Misfire
Owner reports rough idle and engine misfire noise from engine compartment with diagnostic trouble code P0300 (random misfire).
When: <UNKNOWN>
Symptoms owners cite: Rough engine idle; Misfire; Noise from engine compartment
Codes mentioned: P0300 (random misfire)
Synthesized from 16 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had engine trouble with your 2008 Pontiac G6?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2008 Pontiac G6?
It's a documented issue but not catastrophic. 16 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 14 complaints that reported odometer mileage, most engine failures cluster between 75,000 and 113,304 miles, with the median around 98,672. A quarter of owners report trouble before 75,000; a quarter make it past 113,304. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine 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 engine?
No active recalls currently cover engine 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.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2008/Pontiac/G6.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.