The 2004 Outback H6-3.0 with VDC (4-speed automatic) is generally more reliable than its 4-cylinder siblings regarding head gaskets, but the transmission and its cooling system are this platform's Achilles heel, along with age-related oil leaks and some catastrophic engine failures tied to oil starvation.
Transmission Oil Cooler Line Failure & Cooler Contamination
Common · high severity
Typical onset: 80,000-150,000 mi
Symptoms: Transmission fluid weeping or spraying from cooler lines near radiator, Pink fluid pooling under vehicle after parking, Delayed shifts or slipping after fluid loss, Overheating transmission, burnt smell
Fix: Replace both cooler lines (they rust through at crimps), flush transmission cooler or replace radiator if coolant/ATF cross-contamination occurred. If caught early, 2-3 hours labor; if delayed and cooler is contaminated, add radiator replacement and full fluid exchange. Contamination can poison the trans if not flushed properly.
Estimated cost: $400-1,200
Transmission Failure (4-speed Automatic)
Occasional · high severity
Typical onset: 120,000-180,000 mi
Symptoms: Harsh 2-3 shift or slipping between gears, Shuddering on light throttle acceleration, Won't move in Drive or Reverse after warm-up, Check Engine light with transmission codes (P0700 series)
Fix: The 4-speed auto behind the H6 has clutch pack and valve body wear issues. Rebuild requires 8-12 hours labor; many shops recommend replacement with low-mileage used unit (6-8 hours). Fluid changes every 30k can delay but not prevent.
Estimated cost: $2,500-4,500
Rear Differential Mount & Transmission Mount Failure
Common · medium severity
Typical onset: 90,000-140,000 mi
Symptoms: Clunk from underneath when shifting from Park to Drive/Reverse, Vibration at highway speeds that wasn't there before, Excessive drivetrain movement visible when rocking vehicle in gear
Fix: Rubber mounts deteriorate and tear. Rear diff mount is 1.5-2 hours, transmission mount about 2-3 hours due to tight access. Often done together. If left too long, causes additional wear on CV axles and exhaust hangers.
Estimated cost: $500-900
Catastrophic Engine Failure from Oil Starvation
Rare · high severity
Symptoms: Sudden loss of oil pressure with no visible leak, Severe knocking or rattling from engine bay, Engine seizure or rod through block, Metal shavings in oil on routine change (early warning)
Fix: The H6 can develop internal oil passage blockages or pickup tube issues leading to bearing failure. When it lets go, you're looking at spun bearings, scored crank, damaged pistons. Short block replacement is 18-24 hours labor; full rebuild 25-30 hours. Often not economical on a 20-year-old vehicle—used engine swap is common alternative (10-14 hours).
Estimated cost: $4,500-8,000
Valve Cover Gasket & Cam Carrier Leaks
Common · low severity
Typical onset: 100,000-160,000 mi
Symptoms: Oil seepage visible on sides of engine below valve covers, Burning oil smell from exhaust heat shields, Oil drips on garage floor centered under engine, Low oil level between changes without obvious external puddles
Fix: The H6 valve covers are a 4-piece design with cam carrier gaskets underneath. Proper job requires removing covers, cleaning mating surfaces, replacing all gaskets and grommets. 3-4 hours labor per side, often done both sides at once (5-6 hours total). Not urgent but messy and can drip onto exhaust.
Estimated cost: $800-1,400
Front Wheel Bearing Failure
Occasional · medium severity
Typical onset: 80,000-130,000 mi
Symptoms: Growling or humming noise that increases with speed, changes with steering input, ABS light or VDC light due to failing wheel speed sensor in hub, Vibration through steering wheel at highway speeds
Fix: Hub assemblies fail earlier on VDC-equipped models due to integrated wheel speed sensors and additional loads. Replace per side, 1.5-2 hours labor each. Recommend doing both fronts if one fails over 100k to avoid comebacks.
Estimated cost: $400-700
Fuel Filter Clogging (In-Tank)
Occasional · medium severity
Typical onset: 150,000+ mi
Symptoms: Hesitation or stumbling under acceleration, especially uphill, Difficulty starting when tank below 1/4 full, Loss of power at highway speeds, Check Engine light with lean codes (P0171/P0174)
Fix: Filter is part of fuel pump assembly inside tank. Requires dropping tank, 2-3 hours labor. Many techs replace entire pump assembly rather than just filter since labor is same and pumps are aging out too. Not a scheduled service item but needed on neglected high-mileage examples.
Estimated cost: $500-900
Owner tips
Change transmission fluid every 30,000 miles with OEM Subaru ATF—this transmission is sensitive to fluid condition
Inspect transmission cooler lines annually for rust; replace proactively if surface corrosion visible
Monitor oil level every 1,000 miles on higher-mileage examples; the H6 can develop consumption from valve stem seals around 150k
Keep up with timing belt service at 105k intervals—it's interference and failure will cause valve damage
Check differential and transmission mounts during any suspension work; early replacement prevents bigger issues
Buy one under 100k miles with documented transmission services and no leaks—avoid examples over 150k unless transmission has been recently rebuilt or replaced, and budget $1,500/year for age-related repairs.
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.
Be the first to unlock repairs for the 2004 Subaru Outback H6-3.0 VDC
Procedures haven't been generated for this vehicle yet. Become the founding sponsor and we'll generate expert-grade, step-by-step repair walkthroughs for every common job on it — free for every mechanic and DIYer who looks it up after, forever.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 20V001000
2020-01-02 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain 2009-2013 Forester, 2003-2006 Baja, 2004-2011 Impreza, 2004-2014 WRX (STI included), 2003-2014 Legacy and Outback, and 2005-2006 Saab 9-2X vehicles originally sold, or ever registered, in the states of Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands or "Zone A."
These vehicles had their passenger frontal air bag inflators previously replaced under a prior recall using inflators of the same design. The inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, temperature and temperature cycling.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger air bag inflators with alternate inflators, free of charge. The recall began January 7, 2020. Subaru Owners may contact Subaru customer service at 1-844-373-6614. Saab owners may contact the Saab Customer Assistance Center at 1-800-955-9007. Subaru's number for this recall is TKA-20.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 20V002000
2020-01-02 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain 2009-2013 Forester, 2003-2006 Baja, 2004-2011 Impreza, 2004-2014 WRX (including STI), 2003-2014 Legacy and Outback, and 2006 Saab 9-2X vehicles originally sold, or ever registered, in the states of Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia or "Zone B."
These vehicles had their passenger frontal air bag inflators previously replaced under a prior recall using inflators of the same design. The inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, temperature and temperature cycling.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger air bag inflators, free of charge. The recall began January 7, 2020. Subaru owners may contact Subaru customer service at 1-844-373-6614. Saab owners may contact the Saab Customer Assistance Center at 1-800-955-9007. Subaru's number for this recall is TKB-20.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 20V003000
2020-01-02 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain 2009-2013 Forester, 2003-2006 Baja, 2004-2011 Impreza, 2004-2014 WRX (including STI), 2003-2014 Legacy and Outback, and 2005-2006 Saab 9-2X vehicles originally sold, or ever registered, in the states of Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming or "Zone C."
These vehicles had their passenger frontal air bag inflators previously replaced under a prior recall using inflators of the same design. The inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, temperature and temperature cycling.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger air bag inflators, free of charge. The recall began January 7, 2020. Subaru owners may contact Subaru customer service at 1-844-373-6614. Saab owners may contact the Saab Customer Assistance Center at 1-800-955-9007. Subaru's number for this recall is TKC-20.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 16V358000
2016-05-25 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain model year 2003-2004 Legacy, Outback, 2009-2011 Legacy, Outback, Forester, 2006-2011 Impreza, Tribeca, 2003-2006 Baja, and 2006 Saab 9-2x vehicles originally sold or that have ever been registered in Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands, or "Zone A."
These vehicles may be equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules, and used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.
Consequence: An inflator rupture may result in metal fragments striking the vehicle occupants resulting in serious injury or death.
Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger frontal air bag inflator, free of charge. The recall began August 26, 2016. Owners may contact Subaru customer service at 1-856-488-8500. Saab owners may contact GM at 1-800-955-9007. Subaru's number for this recall is TKA-16.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 16V359000
2016-05-25 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain model year 2003-2004 Legacy, Outback, 2006-2008 Impreza, Tribeca, 2006 Saab 9-2x, and 2003-2006 Baja vehicles originally sold or that have ever been registered in Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia, or "Zone B."
These vehicles may be equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules, and used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.
Consequence: An inflator rupture may result in metal fragments striking the vehicle occupants resulting in serious injury or death.
Remedy: Subaru will notify their owners. General Motors will notify Saab owners. Dealers will replace the passenger frontal air bag inflator, free of charge. The recall began August 24, 2016. Owners may contact Subaru customer service at 1-856-488-8500. Subaru's number for this recall is TKB-16.
Note: This notice is only for vehicles that were not covered by 16V-358 for Zone A.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 16V361000
2016-05-25 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain model year 2003-2004 Legacy, Outback, and Baja vehicles originally sold or that have ever been registered in Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming, or "Zone C.".
These vehicles may be equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules, and used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.
Consequence: An inflator rupture may result in metal fragments striking the vehicle occupants resulting in serious injury or death.
Remedy: Subaru will notify owners, and dealers will replace the passenger frontal air bag inflator, free of charge. The recall began August 24, 2016. Owners may contact Subaru customer service at 1-856-488-8500. Subaru's number for this recall is TKC-16.
Note: This recall covers vehicles that were not previously covered in 16V-358 for Zone A or 16V-359 for Zone B.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 15V323000
2015-05-28 · EA15001
Subaru of America, Inc. (Subaru) is recalling certain model year 2003-2004 Subaru Baja vehicles manufactured January 22, 2003, to July 21, 2004, 2004-2005 Impreza vehicles manufactured January 28, 2003, to May 31, 2005, 2003-2008 Subaru Legacy vehicles manufactured January 22, 2003, to May 2, 2008, 2003-2008 Subaru Outback vehicles manufactured February 18, 2003, to May 5, 2008, and 2005 Saab 9-2x vehicles manufactured February 11, 2004, to March 17, 2005. The affected vehicles are equipped with a passenger side frontal air bag that may be susceptible to moisture intrusion which, over time, could cause the inflator to rupture upon its deployment.
Consequence: In the event of a crash necessitating deployment of the passenger's frontal air bag, the inflator could rupture with metal fragments striking the vehicle occupants potentially resulting in serious injury or death.
Remedy: Subaru will notify their owners and General Motors will notify Saab owners. Dealers will replace the passenger air bag inflator, free of charge. The Subaru recall began on June 17, 2015. Owners may contact Subaru customer service at 1-800-782-2783. The Saab recall began on July 27, 2015. Owners of Saab vehicles may call 1-800-955-9007. Subaru's number for this recall is WQR-53. Note: The recall completely supersedes recall 14V-399 (WQL-48) and partially supersedes recall 14V-763 (WQP-51) in that model year 2004 through 2005 Subaru Impreza and model year 2005 Saab 9-2x vehicles are now only part of this campaign. Note: On December 18, 2015 Subaru informed NHTSA of an expansion of this recall to include certain model year 2003-2004 Subaru Baja, 2003-2008 Subaru Legacy and 2003-2008 Subaru Outback vehicles.
AIR BAGS · 14V763000
2014-12-01 · PE14016
Subaru of America, Inc. (Subaru) is recalling certain model year 2003-2004 Legacy and Outback vehicles, and 2003-2005 Baja vehicles sold, or ever registered, in geographic locations associated with high absolute humidity. Specifically, vehicles sold, or ever registered, in Puerto Rico, Hawaii, the U.S. Virgin Islands, Guam, Saipan, American Samoa, Florida and adjacent counties in southern Georgia, as well as the coastal areas of Alabama, Louisiana, Mississippi and Texas. Upon deployment of the passenger side frontal air bag, excessive internal pressure may cause the inflator to rupture.
Consequence: In the event of a crash necessitating deployment of the passengers frontal air bag, the inflator could rupture with metal fragments striking the vehicle occupants potentially resulting in serious injury or death.
Remedy: Subaru will notify their owners. Dealers will replace the passenger air bag inflator, free of charge. The recall began on January 15, 2015. Owners may contact Subaru at 1-800-782-2783. Subaru's number for this recall is WQP-51. Note: This recall supersedes recall 14V-471. This recall has been partially superseded by 15V-323. All 2005 model year Subaru Legacy and Outback vehicles will now be repaired under recall 15V-323.
Airtex Products LP (Airtex) is recalling certain model E8598M, E8518M, E8600M, E8596M, and E8597M fuel pumps manufactured July 26, 2013, and July 29, 2013 and used as aftermarket replacements on Subaru Baja's, Outback's and Legacy's. The affected fuel pumps were sold or installed into the aftermarket applications on or after July 26, 2013, and may may leak fuel from the base of a fuel line connection when the gas tank is full.
Consequence: A fuel leak in the presence of an ignition source increases the risk of a fire.
Remedy: Airtex will notify owners, and will replace the fuel pump, free of charge. Recall is expected to begin on January 2, 2014. Customers may contact Airtex at 1-800-880-3056. The recall is expected to begin during January 2014. This recall is being conducted by Airtex, not by Subaru.
VEHICLE SPEED CONTROL:CABLES · 04V128000
2004-03-16
ON CERTAIN PASSENGER SEDANS, WAGONS, AND SPORT UTILITY VEHICLES, THE CRUISE CONTROL CABLE COULD COME OUT OF ITS TRACK ON THE CRUISE CONTROL LEVER AND LODGE ON THE CONTROL LEVER TAB WHEN THE ACCELERATOR PEDAL IS RELEASED. IF THIS CONDITION OCCURS, THE THROTTLE WILL NOT RETURN TO THE IDLE POSITION AND WILL REMAIN IN AN OPEN POSITION.
Consequence: IF THIS OCCURS DURING VEHICLE OPERATION, THE DRIVER COULD LOSE CONTROL OF THE VEHICLE, WHICH COULD RESULT IN A CRASH.
Remedy: DEALERS WILL INSTALL A CRUISE CONTROL CABLE RETAINING CLIP TO THE CRUISE CONTROL LEVER TAB ON THE THROTTLE SHAFT IN ORDER TO PREVENT THE CRUISE CONTROL CABLE FROM COMING OUT OF ITS TRACK. OWNER NOTIFICATION BEGAN ON APRIL 12, 2004. OWNERS SHOULD CONTACT SUBARU AT 1-800-782-2783.
FUEL SYSTEM, GASOLINE:STORAGE:TANK ASSEMBLY:FILLER PIPE AND CAP · 03V303000
2003-08-20
CERTAIN PASSENGER OR SPORT UTILITY VEHICLES MAY HAVE A LOOSE OR OUT OF POSITION FUEL FILLER HOSE CLAMP.
Consequence: THIS COULD RESULT IN FUEL LEAKAGE. FUEL LEAKAGE IN THE PRESENCE OF AN IGNITION SOURCE COULD RESULT IN A FIRE.
Remedy: DEALERS WILL INSPECT AND TIGHTEN THE CLAMP ON THE FUEL FILLER HOSE. OWNER NOTIFICATION BEGAN AUGUST 27, 2003. OWNERS SHOULD CONTACT SUBARU AT 1-800-782-2783.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.