2009 Pontiac G6 Problems: 14 Known Issues

On the 2006-2009 Pontiac G6, the 3.5L 'wet' V6 routes engine coolant through passages in the intake manifold, and the original plastic-framed lower intake manifold gaskets degrade and leak. This causes external coolant loss or, worse, coolant leaking internally and mixing with the engine oil, which can damage bearings and lead to overheating. (The later 3.9L V6 uses a 'dry' intake and is not prone to the same failure.)

On the 2006-2010 Pontiac G6, g6 owners frequently see a 'Reduced Engine Power' message with the car dropping into limp mode, triggered by throttle position sensor voltage-correlation faults. The throttle body's integrated TPS develops dirty or shorting solder points (sometimes attributed to 'tin whiskers') and corrosion at the connector, so the two throttle sensor signals disagree and the ECM cuts power for safety.

On the 2006-2010 Pontiac G6 2.4L Ecotec LE5, the 2.4L Ecotec LE5 in 2006-2010 G6 (and shared Cobalt SS, Malibu, HHR, Saturn Aura/Ion, Solstice) develops timing chain stretch — a very well-documented engineering issue across Ecotec forums and independent shops. Root cause: GM's original Oil Life Monitor allowed intervals up to 12,000 miles, starving the chain. Note: while GM issued Special Coverage Adjustment 11340C covering timing chain wear on the 2.8L/3.6L LP1/LY7/LLT V6, the 2.4L Ecotec did NOT receive the same blanket warranty extension. Some owners obtained goodwill repairs through dealer-level escalation.

On the 2008-2010 Pontiac G6, gM recalled 2008-2010 Pontiac G6 sedans and coupes built with the 4-speed automatic transmission because the tabs on the transmission shift cable end can fracture and separate. Once those tabs break, the shift lever in the console no longer reliably reflects what the transmission is actually doing — the indicated gear and the real gear can disagree. The specific hazard NHTSA describes is that a G6 driver can slide the lever into 'PARK' and pull the ignition key out while the transmission is not in PARK at all, so the car is left unsecured after the driver believes it has been parked. This is a defect in the linkage between the shifter and the gearbox, not in the transmission itself, so a G6 that shifts and drives normally can still have it. The campaign covered 426,240 vehicles in total across every model included in the recall; that figure is campaign-wide and is not a count of G6s.

On the 2005-2009 Pontiac G6, on G6 models with the 4-speed automatic, the transmission shift cable can fracture, or the shift cable adjustment clip may not be fully engaged. When this happens the shifter position and the actual transmission gear no longer match, so the driver can move the lever to Park and remove the key while the transmission is not truly in Park. This created a documented rollaway hazard and was the subject of NHTSA recalls 09V073000 and 14V224000.

On the 2005-2010 Pontiac G6, if you own a 2005-2010 Pontiac G6 built between May 26, 2004 and January 4, 2010, it falls under GM's safety recall 14V252000. The defect is increased resistance in the Body Control Module (BCM) connection, which can produce voltage fluctuations on the Brake Apply Sensor (BAS) circuit. Per NHTSA, one result of those fluctuations is improper brake light operation. Because the problem lies in the electrical connection feeding the BCM and BAS rather than in a single failed component, it is corrected by treating and securing the connectors themselves. The G6 was one of four GM cars swept up in this campaign alongside the Chevrolet Malibu, Malibu Maxx and Saturn Aura; the 2,440,524-vehicle figure NHTSA publishes is the total for the entire campaign, not for the G6 alone. NHTSA rates the consequence as an increased risk of a crash.

On the 2005-2010 Pontiac G6, the G6 is notorious for low-beam headlights that burn out or stop working repeatedly. The root cause is that the bulb generates more heat than the cheap plastic headlamp connector/socket can handle, so the connector overheats, melts, and loses contact. Owners often replace bulbs only to have them fail again within months because the connector and wiring are the real problem.

On the 2005-2010 Pontiac G6, common G6 fault pattern: simultaneous Service StabiliTrak, Service Traction Control, ABS warning lights, and sometimes Reduced Engine Power message. GM-acknowledged issue (TSB 08-05-22-009, later safety recall 14V252000 covering 2005-2010 G6) traced to fretting corrosion and increased resistance on terminals of the Body Control Module connectors (the C2/X2 connector), reached behind the right-side front floor console side trim panel in the passenger footwell; the resulting brake apply sensor signal fault can disable traction control and StabiliTrak. Micro-vibration causes oxidation on the contact surfaces; moisture intrusion from sunroof drains can accelerate it.

On the 2005-2010 Pontiac G6, the G6's PASS-Key III+ theft-deterrent system can falsely trip, illuminating the security light and preventing the engine from starting. Common causes are a damaged key transponder or a fault in the key-reading circuit at the ignition lock cylinder or its wiring, so the system fails to recognize the key. The well-known 10-minute relearn trick only resets it temporarily; the fault usually returns until the faulty key or cylinder component is replaced.

On the 2006-2009 Pontiac G6, the G6 convertible (2006-2009) uses a complex 2-piece clamshell retractable hardtop with hydraulic rams and multiple position sensors. Hydraulic ram fluid leaks, weak/failed hydraulic pumps, and bad microswitches/latch sensors leave the top stuck halfway, lifting the trunk but failing to clear the windshield, or refusing to deploy at all.

On the 2005-2010 Pontiac G6, g6 rocker panels and lower door edges develop severe rust-through, especially in salt-belt states. The rockers are welded into the body sill (not bolt-on), with poor factory undercoating in the seam. Owners report visible holes and crumbling metal by 8-12 years of age. Same pattern as sibling Saturn Aura and Chevy Malibu (Epsilon platform).

On the 2005-2010 Pontiac G6, g6 sedans equipped with the large panoramic (multi-panel) sunroof commonly leak water into the cabin. The frequent culprit is the sunroof drain tubes, which GM cut short, allowing them to pull off their outlets so water drains onto the seat belts, under the rear seat, and into the carpet. Owners also report the motorized sunshade buckling/breaking, panel pins/screws falling out, and the roof getting stuck.

On the 2005-2009 Pontiac G6, nHTSA campaigns 14V153000 and 15V064000 together cover affected 2005-2009 Pontiac G6 vehicles for sudden loss of electric power-steering assist. The remedy depends on model year and build window and can involve the torque sensor, EPS motor/controller or applicable bulletin. The 1,373,177-vehicle figure covers the whole campaign, not just the G6.

On the 2005-2010 Pontiac G6, the sealed front wheel bearing/hub assemblies on the 2005-2010 G6 commonly wear out, producing a loud humming or grinding noise that rises with speed and changes when turning. If a turn to one side worsens the noise, the failing bearing is typically on the opposite side. Left unrepaired, a bearing can seize or fail completely, which is a serious safety risk.