2007 GMC Envoy

The 4.2L LL8 Atlas inline-6 engine develops severe timing chain stretch and guide failure. The primary and secondary timing chain guides crack, break apart, and send plastic debris into the oil pan. Symptoms include a loud rattling noise on startup that may persist, check engine lights with timing codes, and rough running. Complete guide disintegration can cause the chain to skip teeth, destroying the engine.

Replace all timing chains, tensioners, and guides as a complete set. This is a major repair requiring significant engine disassembly. Use updated GM guide parts with improved materials. Flush the oil pan and pickup tube screen to remove plastic debris. Maintain strict oil change intervals with quality synthetic oil to extend the life of the replacement parts.

The HVAC blend door actuators fail frequently on the GMT360 platform, producing a repetitive clicking or knocking noise from behind the dashboard. The actuator gears strip and the blend door gets stuck, causing the system to blow only hot or only cold air regardless of the temperature setting. The noise is particularly annoying as it occurs every time the ignition is turned on.

Replace the failed HVAC blend door actuator. The Envoy has multiple actuators controlling temperature, mode, and recirculation doors. The driver-side temperature actuator is the most common failure. Accessing the actuators requires partial dashboard disassembly. Use AC Delco replacement actuators for proper fit and function.

The Envoy is plagued by various electrical issues including intermittent gauge failures where the speedometer, tachometer, or fuel gauge stop working or read incorrectly. The instrument cluster stepper motors fail, causing the gauge needles to stick or read zero. Other electrical issues include power window failures, door lock malfunctions, and intermittent no-start conditions.

Replace or rebuild the instrument cluster. Cluster repair services are available that replace all stepper motors and re-solder the circuit board for $100-$200. For power window issues, replace the window regulator and motor assembly. For no-start conditions, inspect and clean the battery cables and ground connections, particularly the engine-to-chassis ground strap.

The engine cooling fan clutch fails, either locking up (causing excessive noise and drag) or freewheeling (causing overheating). A failed fan clutch that does not engage properly allows the engine to overheat in slow traffic and during towing. The 4.2L inline-6 runs hot under load, making a functioning fan clutch critical. Owners report overheating warnings during summer driving.

Replace the fan clutch assembly. A locked-up fan clutch will cause a loud roaring noise and reduced fuel economy. A freewheeling clutch will not cool adequately at idle or low speeds. Also inspect the radiator for clogging or corrosion, the thermostat for proper operation, and the coolant level and condition.

The front differential and transfer case develop fluid leaks from the output shaft seals, pinion seals, and case halves. Low fluid levels in either component can cause gear damage, bearing failure, and eventual loss of four-wheel drive function. Owners notice fluid spots under the front of the vehicle and may hear grinding or whining noises from the drivetrain when 4WD is engaged.

Replace the leaking seals and top off or replace the fluid in the front differential and transfer case. If the components have been run with low fluid, inspect the gears and bearings for damage. The transfer case encoder motor and front axle disconnect actuator should also be inspected, as they are common failure points on the GMT360 platform.

General Motors LLC (GM) is recalling certain model year 2006-2007 Buick Rainier, Chevrolet Trailblazer and GMC Envoy vehicles, and 2006 GMC Envoy XL and Chevrolet Trailblazer EXT vehicles. Fluid may enter into the driver's door master power window switch module, causing corrosion that could result in a short in the circuit board, causing window switches to become inoperative. Previously, the affected vehicles may have had their master power window switch module treated with a protective coating, instead of having it replaced.

The protective coating may not eliminate the risk that the circuit board could short and result in a fire, even while the vehicle is unattended.

GM will notify owners, and dealers will install a new driver's door switch module, free of charge. The recall began on November 2, 2015. Owners may contact Buick customer service at 1-800-521-7300, Chevrolet customer service at 1-800-222-1020, and GMC customer service at 1-800-462-8782. GM's number for this recall is 15700.

General Motors LLC (GM) is recalling certain model year 2007 Pontiac Grand Prix, 2006-2009 Buick LaCrosse, 2006-2007 Buick Rainier, Chevrolet Trailblazer, GMC Envoy, 2006 Chevrolet Trailblazer EXT, GMC Envoy XL, 2006-2008 Isuzu Ascender, and Saab 9-7x vehicles. In the affected vehicles, the headlamp driver module (HDM) may overheat and fail, causing the headlamps and daytime running lights to not illuminate.

Headlamps that do not illuminate reduce the driver's ability to see the roadway and reduce the vehicle's visibility to oncoming vehicles, both of which increase the risk of a vehicle crash.

GM will notify owners, and dealers will replace the HDM, free of charge. The recall began on May 17, 2016. Owners may contact Buick customer service at 1-800-521-7300 or Pontiac customer service at 1-800-762-2737. GM's number for this recall is 14291.

General Motors LLC (GM) is recalling certain model year 2005-2007 SAAB 9-7x; 2006 Chevrolet Trailblazer EXT and GMC Envoy XL; and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier and Isuzu Ascender vehicles. Fluid may enter the driver's door master power window switch module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.

A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.

GM will notify owners, and dealers will inspect the part number on the door module, and install a new door module if necessary, free of charge. Parts for the remedy are not currently available. An interim letter was mailed to owners in August 2014. A second owner letter will be mailed when parts are available. Owners may contact GM customer service at 1-800-521-7300 (Buick), 1-800-222-1020 (Chevrolet), 1-800-462-8782 (GMC), 1-800-955-9007 (SAAB), and 1-800-255-6727 (Isuzu). GM's number for this recall is 14309. NOTE: This recall provides a new remedy for all vehicles covered by recall 13V-248. Vehicles whose modules were modified but not replaced as part of the previous recall remedy must have their vehicles remedied again under this campaign.

General Motors (GM) is recalling certain model year 2005-2007 SAAB 9-7x; 2006 Chevrolet Trailblazer EXT and GMC Envoy XL; and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier and Isuzu Ascender vehicles. Fluid may enter the driver's door module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.

A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.

Owners will be contacted and dealers will test the driver's door module. If the module is functioning properly, a protective coating will be applied. If the module is not functioning properly, it will be replaced. These repairs will be done free of charge. GM will notify Buick, Chevrolet, and GMC owners, Isuzu and Saab will contact their respective owners. The recall began on August 2, 2013. Buick owners may contact the owner center at 1-800-521-7300, Chevrolet owners at 1-866-694-6546, GMC owners at 1-866-996-9463, Isuzu owners at 1-800-255-6727, and Saab owners at 1-800-955-9007. GM's campaign number is 12180. This recall is an expansion of recall 12V-406.

General Motors (GM) is recalling certain model year 2006 Chevrolet Trailblazer EXT and GMC Envoy XL and 2006-2007 Chevrolet Trailblazer, GMC Envoy, Buick Rainier, SAAB 9-7x, and Isuzu Ascender vehicles, originally sold or currently registered in Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, Wisconsin, and the District of Columbia. Fluid may enter the driver's door module, causing corrosion that could result in a short in the circuit board. A short may cause the power door lock and power window switches to function intermittently or become inoperative. The short may also cause overheating, which could melt components of the door module, producing odor, smoke, or a fire.

A short in the circuit board could lead to a fire, increasing the risk of personal injury. A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made.

Parts for this recall are expected to available in March 2013. GM will notify Buick, Chevrolet, and GMC owners when parts are available. Buick owners may contact the owner center at 1-800-521-7300, Chevrolet owners at 1-866-694-6546, and GMC owners at 1-866-996-9463. Isuzu owners will be notified by Isuzu Motors when parts are available. Owners may contact Isuzu customer service at 1-800-255-6727. SAAB owners will be notified by SAAB Cars North America when parts are available and for inquiries, owners may call SAAB customer service at 1-800-955-9007.