The 2002 GMC Envoy with the 4.2L I6 (Vortec) is a body-on-frame mid-size SUV that suffers from catastrophic lower-end engine failures and transmission cooling issues, both of which often result in total powertrain replacement rather than economical repair.
Symptoms: Sudden heavy knocking or ticking from lower engine block, often after cold start, Low oil pressure warning, metal shavings in oil during change, Catastrophic loss of power, engine seizure if driven after knock begins
Fix: Lower-end bearing failure requires either short-block replacement (12-16 hours) or full engine swap (14-18 hours). Machine work on crank journals rarely cost-effective due to labor depth. Most shops recommend reman or junkyard engine.
Estimated cost: $3,500-6,500
Transmission Oil Cooler Line Failure and Cross-Contamination
Common · high severity
Typical onset: 80,000-140,000 mi
Symptoms: Pink or milky transmission fluid (coolant intrusion via leaking internal cooler), Erratic shifting, slipping, or no movement after cooler line rupture, Coolant loss with no visible external leaks, transmission overheating
Fix: External cooler lines rust through (1.5 hours to replace), but internal radiator cooler failure contaminates trans fluid and destroys clutch packs. Requires transmission rebuild or replacement (8-12 hours) plus new radiator and full flush of cooling system. Always replace external cooler lines preemptively during any radiator work.
Estimated cost: $2,800-5,200
Transfer Case Mode Actuator and Encoder Motor Failure
Common · medium severity
Typical onset: 70,000-120,000 mi
Symptoms: Service 4WD message on dash, inability to engage or disengage 4WD modes, Grinding or clicking from transfer case during mode changes, Stuck in 2WD or 4WD with no ability to shift between modes
Fix: Encoder motor or mode actuator motor on transfer case fails (2.5-3.5 hours to replace both). These are external bolt-on units. Sometimes requires reprogramming or relearning procedure with Tech2 scan tool after replacement.
Estimated cost: $600-1,200
Cylinder Head Gasket Failure (Between Cylinders)
Occasional · high severity
Typical onset: 100,000-150,000 mi
Symptoms: White smoke from exhaust, coolant loss with no external leaks, Misfire on adjacent cylinders (common on 3-4 or 4-5), Overheating, bubbling coolant reservoir, combustion gases in cooling system
Fix: Head gasket failure on 4.2L I6 requires both heads to be removed, inspected, and resurfaced (10-14 hours). Often find warped heads requiring machine work ($150-300 per head). If caught late, can damage head surface beyond spec requiring replacement heads.
Estimated cost: $2,200-3,800
HVAC Blend Door Actuator Clicking and Mode Door Failure
Common · low severity
Typical onset: 60,000-100,000 mi
Symptoms: Loud clicking or ticking from behind dash, especially on startup or temp changes, No heat or AC in certain zones, air blows from wrong vents, Temperature control works on one side only (if dual-zone equipped)
Fix: Multiple actuators control blend and mode doors. Clicking is stripped gear inside actuator (1.5-2.5 hours per actuator depending on location). Driver-side temp actuator requires partial dash removal. Mode door itself can break, requiring deeper dash work (4-6 hours).
Estimated cost: $250-900
Front Differential Fluid Contamination and Bearing Noise
Occasional · medium severity
Typical onset: 90,000-140,000 mi
Symptoms: Whining or howling from front end during acceleration or coasting, Clunking when engaging 4WD, vibration at highway speeds in 4WD, Metal shavings in front diff fluid during service
Fix: Front differential bearings wear due to lack of maintenance (fluid rarely changed). Requires diff teardown and bearing replacement (4-6 hours). If caught early, bearing service is sufficient; if neglected, ring-and-pinion or carrier damage requires full rebuild or replacement unit.
Estimated cost: $800-2,400
Fuel Pump and Fuel Pressure Regulator Issues
Occasional · medium severity
Typical onset: 100,000-160,000 mi
Symptoms: Hard starting when hot, long crank before firing, Stalling at idle after deceleration, surging under light throttle, Check engine light for lean codes (P0171/P0174) with no vacuum leaks found
Fix: In-tank fuel pump assembly fails or pressure regulator leaks internally, causing low fuel pressure. Requires tank drop and pump replacement (2.5-3 hours). Always check fuel pressure before condemning pump—filter clogs easily if not changed every 30k miles on this platform.
Estimated cost: $600-1,100
Owner tips
Change transmission fluid and filter every 40,000 miles and inspect cooler lines for rust—this prevents the single most expensive failure mode
Install external transmission cooler and bypass internal radiator cooler if towing or operating in hot climates
Use full-synthetic 5W-30 oil and change every 5,000 miles to extend bearing life on the 4.2L I6—this engine is oil-starved by design at the lower end
Flush front and rear differential fluid at 60k and 120k miles; these are often neglected and lead to expensive rebuilds
Replace fuel filter every 30,000 miles—clogged filter overworks pump and causes drivability issues
Hard pass unless under $3,000 and you have a backup vehicle—the 4.2L I6 and 4L60E transmission are both ticking time bombs that often require replacement within 20k miles of purchase at typical used-car mileage.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
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CERTAIN MAXZONE HEADLIGHT ASSEMBLIES, DEPO BRAND, P/NO 335-1120L-AS, SOLD FOR USE AS AFTERMARKET EQUIPMENT FOR THE ABOVE LISTED PASSENGER VEHICLES. DURING PRODUCTION THE LAMP HOUSING SHAPE DEFORMED DISTORTING THE ASSEMBLY ANGLE OF THE REFLECTOR AND INFLUENCED THE AIMING POSITION. THESE HEADLAMPS FAIL TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT.
Consequence: DECREASED LIGHTING VISIBILITY MAY RESULT IN A VEHICLE CRASH.
Remedy: MAXZONE WILL NOTIFY OWNERS AND OFFER REIMBURSEMENT FOR ANY NONCOMPLIANT HEADLIGHTS. THE RECALL BEGAN ON FEBRUARY 16, 2007. OWNERS MAY CONTACT MAXZONE AT 909-822-3288.
ENGINE AND ENGINE COOLING · 04V289000
2004-06-23 · EA03007
SOME SPORT UTILITY VEHICLES EQUIPPED WITH AN ELECTRONICALLY CONTROLLED AIR SUSPENSION (ECAS) HAVE A CONDITION IN WHICH THE ECAS MAY PRODUCE A BRIEF ELECTRICAL SPIKE WHILE THE VEHICLE IS OPERATING. THIS ELECTRICAL SPIKE CAN DISRUPT THE POWERTRAIN CONTROL MODULE (PCM) CAUSING THE VEHICLE TO STALL.
Consequence: IF THE SPIKE DAMAGES THE PCM, THE VEHICLE MAY NOT RESTART. IF THIS HAPPENS WHILE THE VEHICLE IS MOVING, A CRASH COULD OCCUR WITHOUT PRIOR WARNING.
Remedy: DEALERS WILL INSTALL A WIRING HARNESS. THE RECALL WILL BEGIN ON AUGUST 19, 2004. OWNERS SHOULD CONTACT OLDSMOBILE AT 1-800-630-6537 OR GMC AT 1-866-996-9463.
SEAT BELTS · 04V201000
2004-04-28
CERTAIN LIGHT DUTY PICKUP TRUCKS AND SPORT UTILITY VEHICLES FAIL TO CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 209, "SEAT BELT ASSEMBLIES." ONE OF THE TWO SENSORS IN THE DRIVER'S AND FRONT PASSENGER'S SEAT BELT RETRACTORS COULD BE INOPERATIVE. THE SEAT BELT RETRACTORS WILL LOCK WHEN THE BELT WEBBING IS EXTRACTED DURING A CRASH; HOWEVER, THE MECHANISM THAT LOCKS THE SEAT BELT RETRACTOR WHEN THE VEHICLE DECELERATES QUICKLY, SUCH AS HEAVY BRAKING, MAY NOT OPERATE AS INTENDED.
Consequence: IF THIS WERE TO OCCUR, THE SAFETY BELT MAY NOT RESTRAIN THE OCCUPANT AS INTENDED DURING A CRASH, AND COULD RESULT IN INJURY TO THE OCCUPANT.
Remedy: DEALERS WILL INSPECT THE DRIVER AND FRONT PASSENGER SAFETY BELT RETRACTORS, AND REPLACE THEM IF NECESSARY. OWNER NOTIFICATION BEGAN ON JUNE 24, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463, OR OLDSMOBILE AT 1-800-630-6537.
VISIBILITY:WINDSHIELD WIPER/WASHER · 04V046000
2004-02-04 · EA04002
CERTAIN SPORT UTILITY VEHICLES HAVE WINDSHIELD WIPER SYSTEMS THAT WILL NOT TURN ON, CEASE OPERATION WHILE IN USE, FAIL TO TURN OFF/ON BY THEMSELVES (MOISTURE SENSITIVE WIPER SYSTEM), OR HAVE CONTINUOUS WINDSHIELD WASHER PUMP OPERATION BECAUSE THE PRESENCE OF WATER WITHIN THE WIPER MODULES CAN EITHER CAUSE A SHORT CIRCUIT OR CAN LEAD TO THE CORROSION OF COMPONENTS WITHIN THE MODULE.
Consequence: DEPENDING ON THE OCCURRENCE AND WEATHER SITUATION, DRIVER VISIBILITY COULD BE REDUCED, WHICH COULD RESULT IN A CRASH.
Remedy: DEALERS WILL COVER THE WINDSHIELD WIPER MODULE VENT HOLE WITH A PATCH. ALSO, THE WIPER MOTOR, CIRCUIT BOARD, AND ELECTRICAL CONNECTOR WILL BE INSPECTED TO SIGNS OF WATER INTRUSION AND/OR CORROSION AND BE REPLACED AS REQUIRED. THE RECALL BEGAN JULY 6, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438; OLDSMOBILE AT 1-800-630-6537; OR GMC AT 1-866-996-9463.
CERTAIN MINIVANS, PASSENGER AND SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 225, "CHILD RESTRAINT ANCHORAGE SYSTEM." THE OWNER'S MANUAL DOES NOT EXPLAIN THE MEANING OF THE LOCATION SYMBOLS FOR THE CHILD RESTRAINT LOWER UNIVERSAL ANCHORAGE SYSTEM.
Consequence: THIS DOES NOT MEET THE REQUIREMENTS OF THE STANDARD.
Remedy: OWNERS WILL BE PROVIDED WITH A SUPPLEMENT FOR THEIR OWNER'S MANUAL. THIS SUPPLEMENT DESCRIBES AND SHOWS THE LOCATION SYMBOLS FOR THE CHILD RESTRAINT ANCHORS THAT ARE LOCATED IN THE VEHICLE AND ON THE CHILD RESTRAINT OR BOOSTER CUSHION. OWNER NOTIFICATION BEGAN AUGUST 18, 2003. OWNERS SHOULD CONTACT BUICK AT 1-866-608-8080, CADILLAC AT 1-866-982-2339, CHEVROLET AT 1-800-630-2438, GMC AT 1-866-996-9463, PONTIAC AT 1-800-620-7668, OR OLDSMOBILE AT 1-800-630-6537.
CERTAIN SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARDS NO. 101, "CONTROL LOCATION, IDENTIFICATION, AND ILLUMINATION" AND NO. 208, "OCCUPANT CRASH PROTECTION." THESE VEHICLES HAVE AN INTERMITTENT CONDITION DURING VEHICLE START-UP IN WHICH THE INSTRUMENT PANEL CLUSTER MAY NOT PROPERLY POWER UP, RESULTING IN MOST OF THE DISPLAYS, TELLTALE LIGHTS, AND FUNCTIONS (EXCEPT THE SERVICE ENGINE LIGHT, TURN SIGNAL INDICATORS, AND THE INSTRUMENT PANEL CLUSTER BACKLIGHTING) BEING INOPERATIVE.
Consequence: THESE VEHICLES DO NOT COMPLY WITH THE STANDARD.
Remedy: DEALERS WILL REPROGRAM THE INSTRUMENT PANEL CLUSTER. OWNER NOTIFICATION BEGAN MAY 29, 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020, GMC AT 1-800-462-8782, OR OLDSMOBILE AT 1-800-442-6537.
POWER TRAIN:AUTOMATIC TRANSMISSION · 03V075000
2003-03-06
CERTAIN SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 114, "THEFT PROTECTION." THESE VEHICLES ARE EQUIPPED WITH A MECHANICAL OVERRIDE THAT COULD ALLOW THE IGNITION KEY TO BE REMOVED WITH THE SHIFT LEVER IN A POSITION OTHER THAN PARK. IN ADDITION, THESE VEHICLES HAVE AN OVERRIDE THAT CAN ALLOW THE TRANSMISSION TO BE SHIFTED OUT OF PARK WITH THE IGNITION IN THE OFF POSITION.
Consequence: THESE OVERRIDES ARE NOT PERMITTED UNLESS THE VEHICLE HAS A LOCKING STEERING COLUMN.
Remedy: DEALERS WILL ELIMINATE THESE CONDITIONS BY DISABLING THE OVERRIDES. OWNER NOTIFICATION BEGAN ON MAY 29, 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020, GMC AT 1-800-462-8782, OLDSMOBILE AT 1-800-442-6537, OR HUMMER AT 1-866-486-6376.
STRUCTURE:BODY · 02V273000
2002-10-04
CERTAIN SPORT UTILITY VEHICLES ARE MISSING WELDS ON THE REAR FLOOR PLAN.
Consequence: IN A CRASH, MISSING WELDS COULD DEGRADE PERFORMANCE OF THE THIRD ROW SEAT AND SAFETY BELT ANCHORAGE AND OCCUPANTS COULD RECEIVE GREATER INJURIES.
Remedy: DEALERS WILL INSPECT THE VEHICLE FOR MISSING WELDS. IF MISSING WELDS ARE FOUND, GM WILL EXCHANGE THE VEHICLE FOR AN EQUIVALENT VEHICLE OR PROVIDE A REFUND OF THE PURCHASE PRICE. OWNER NOTIFICATION BEGAN OCTOBER 4, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.
FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS · 02V121000
2002-08-23 · RQ02010
ON CERTAIN SPORT UTILITY VEHICLES, A FUEL FILTER FITTING CAN BECOME DISCONNECTED. IF THIS WERE TO OCCUR WHILE ATTEMPTING TO START THE ENGINE, A NO-START CONDITION WOULD RESULT AND FUEL WOULD BE PUMPED OUT THE FUEL FILTER ONTO THE GROUND.
Consequence: IF THE FITTING BECOMES DISCONNECTED WHILE THE VEHICLE IS IN MOTION, THE ENGINE WOULD STOP DUE TO INADEQUATE FUEL SUPPLY AND CAUSE A LOSS OF POWER STEERING ASSIST. IF AN IGNITION SOURCE WERE PRESENT, FUEL LEAKAGE FROM A DISCONNECTED FUEL FILTER FITTING COULD RESULT IN A FIRE.
Remedy: DEALERS WILL REPLACE THE FUEL FILTER QUICK CONNECT RETAINERS. OWNER NOTIFICATION BEGAN SEPTEMBER 20, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020. GMC AT 1-800-462-8782, OR OLDSMOBILE AT 1-800-442-6537.
AIR BAGS:FRONTAL · 02V222000
2002-08-09
CERTAIN PASSENGER, MINI VANS, AND SPORT UTILITY VEHICLES HAVE AN AIR BAG INFLATOR ON THE DRIVER'S SIDE THAT COULD FRACTURE AT A WELD DURING A DEPLOYMENT.
Consequence: PIECES OF THE INFLATOR COULD STRIKE AND INJURE VEHICLE OCCUPANTS AND THE AIR BAG CUSHION WOULD NOT INFLATE FULLY, REDUCING THE CAPABILITY OF THE BAG TO PROTECT THE DRIVER.
Remedy: DEALERS WILL INSPECT, AND REPLACE, IF NECESSARY, THE AIR BAG MODULE ASSEMBLY ON THE DRIVER'S SIDE. OWNER NOTIFICATION BEGAN AUGUST 15, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT BUICK AT 1-800-521-7300, CADILLAC AT 1-800-458-8006, CHEVROLET AT 1-800-222-1020, GMC AT 1-800-462-8782, OLDSMOBILE AT 1-800-442-6537, OR PONTIAC AT 1-800-762-2737.
POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE) · 01V334000
2001-10-17
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES EQUIPPED WITH 4-WHEEL DRIVE. THE CALIBRATION OF THE TRANSFER CASE CONTROL MODULE COULD CAUSE INSUFFICIENT HIGH SPEED GEAR ENGAGEMENT.
Consequence: IF THE GEAR IS NOT ENGAGED, THE VEHICLE CAN ROLL WHEN THE TRANSMISSION IS IN "PARK" AND A CRASH COULD RESULT WITHOUT WARNING.
Remedy: DEALERS WILL UPDATE THE TRANSFER CASE CONTROL MODULE CALIBRATION TO INCREASE GEAR ENGAGEMENT. OWNER NOTIFICATION BEGAN NOVEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.
POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE) · 01V283000
2001-09-05
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES (4 WHEEL-DRIVE). SOME OF THESE VEHICLES WERE BUILT WITH A RANGE SHIFT COLLAR IN THE TRANSMISSION TRANSFER CASE THAT CONTAINS CRACKS.
Consequence: THIS CONDITION COULD RESULT IN A COMPLETE FRACTURE OF THE RANGE SHIFT COLLAR AND SUBSEQUENT LOSS OF VEHICLE FORWARD AND REVERSE GEARS, AND THE INABILITY TO MAINTAIN "PARK" POSITION. THIS INCREASES THE RISK OF A VEHICLE CRASH RESULTING FROM UNINTENDED MOVEMENT OF A PARKED VEHICLE.
Remedy: DEALERS WILL REPLACE THE TRANSFER CASES AND UPDATE THE CONTROL MODULE CALIBRATION. OWNER NOTIFICATION BEGAN SEPTEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.
STRUCTURE:BODY · 01V158000
2001-05-16
VEHICLE DESCRIPTION: CERTAIN SPORT UTILITY VEHICLES FAIL TO COMPLY WITH REQUIREMENTS OF FMVSS NO. 201, "OCCUPANT PROTECTION IN INTERIOR IMPACTS." THESE VEHICLES HAVE A CONSOLE COVER/ARMREST LID LATCH THAT COULD RELEASE AT LESS THAN THE 10G VERTICAL LOAD REQUIREMENT OF THE STANDARD.
Consequence: IN THE EVENT OF A CRASH, THE CONSOLE COVER COULD OPEN AND THE COVER OR ITEMS STORED UNDER IT COULD INJURE AN OCCUPANT.
Remedy: DEALERS WILL REPLACE THE CONSOLE LATCH MECHANISM AND INSTALL A STRIKER PLATE.
OWNER NOTIFICATION BEGAN JULY 16, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT GMC AT 1-800-462-8782.
SUSPENSION:FRONT:CONTROL ARM:LOWER ARM · 01V126000
2001-04-12
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES. UNDER CERTAIN CIRCUMSTANCES THE FRONT LOWER CONTROL ARM BRACKETS MAY FRACTURE. THIS FRACTURE COULD RESULT IN SEPARATION OF THE FRONT LOWER CONTROL ARM FROM THE FRAME.
Consequence: A SEPARATION COULD RESULT IN LOSS OF VEHICLE CONTROL, RESULTING IN A CRASH.
Remedy: DEALERS WILL REPLACE THE LEFT AND RIGHT FRONT LOWER CONTROL ARM BRACKETS. OWNER NOTIFICATION BEGAN BY TELEPHONE ON APRIL 4, 2001. THE FOLLOWUP LETTER TO CONSUMERS WAS MAILED MAY 3, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020, OLDSMOBILE AT 1-800-442-6537, OR GMC AT 1-800-462-8782.
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