IllustrationPOWER BRAKE BOOSTER BRAKE SYSTEM LOCK ON HIGHWAY. POWER STEERING WENT OUT WHILE DRIVING NO WARNING . ALMOST HAD ACCIDENT ON SNOW DUE TO BAD. TRANSMISSION. TRANSMISSION WENT OUT ON HIGHWAY. UNABLE TO START CAR IGNITION SWITCH.
2008 Mercury Mariner
Owner reports · Recalls · Investigations
More warning signs than most Mariner years
Owner complaints for the 2008 Mercury Mariner are substantially higher than the model-year median of 63.
About this comparison →How this year compares
Owner complaints by model year
Compare all Mariner years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
220–25K
2125–50K
5150–75K
8075–100K
146100–150K
84150K+
404 reports with mileage · 57 unknown
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Steering. Review the 297 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Power Train. Review the 66 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Vehicle Speed Control. Review the 31 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
9 crash reports0 fire reports5 injury reports
Service Brakes complaints
29 reportsWHILE DRIVING ON THE HIGHWAY CHECK BRAKE SYSTEM MESSAGE AND BRAKE LIGHT COMES ON VEHICLE BRAKING BECOMES VERY HARD TO STOP. AFTER STOPPING VEHICLE AND TURNING VEHICLE OFF AND ON SEVERAL TIMES BRAKE WARNING LIGHT GOES OFF AND VEHICLE DRIVES NORMALLY FOR A FEW DAYS THAN PROBLEM COMES BACK. WHILE AT A LIGHT ONE DAY BRAKE WARNING LI…
Read full complaint
WHILE DRIVING ON THE HIGHWAY CHECK BRAKE SYSTEM MESSAGE AND BRAKE LIGHT COMES ON VEHICLE BRAKING BECOMES VERY HARD TO STOP. AFTER STOPPING VEHICLE AND TURNING VEHICLE OFF AND ON SEVERAL TIMES BRAKE WARNING LIGHT GOES OFF AND VEHICLE DRIVES NORMALLY FOR A FEW DAYS THAN PROBLEM COMES BACK. WHILE AT A LIGHT ONE DAY BRAKE WARNING LIGHT CAME ON DROVE FOR APPROXIMATELY 1 MILE AND NO BRAKES AT ALL WAS ABLE TO TURN IN TO A PARKING LOT AND APPLY THE EMERGENCY BRAKES TO STOP. LEFT VEHICLE OVER NIGHT THE NEXT DAY TURNED VEHICLE ON AND OFF SEVERAL TIME AND BRAKES BEGAN TO WORK. MADE APPOINTMENT WITH DEALER WHO ADVISED IT WILL BE THREE WEEKS TO GET IT IN. AFTER THREE WEEKS TO TAKE VEHICLE IN A WEEK LATER WAS ADVISED ABS HCU WAS PROBABLY BAD. COST FOR NEW ABS HCU MODULE $4700 FOR THE PART ALONE. PICKED UP VEHICLE WITHOUT HAVING IT FIXED AND DROVE LOCALLY FOR A FEW WEEKS WITH BRAKE IN "MANUAL MODE" UNTIL I TRIED TO STOP FOR A YELLOW LIGHT IN THE RAIN AND SLID THROUGH THE INTERSECTION SINCE ONLY THE BACK BRAKES WORKS IN MANUAL MODE. LATER ORDERED A REFURBISHED ABS HCU MODULE COST $1400.00, THE FORD DEALER IS THE ONLY ONE WHO CAN INSTALL UNIT SINCE THE MODULE HAS TO BE PROGRAMED TO THE VEHICLE SOFTWARE. TOOK TWO WEEKS TO GET AN APPOINTMENT DEALER HAD VEHICLE FOR ANOTHER SIX WEEKS TRYING TO PROGRAM AND BLEED BRAKE SYSTEM. DEALER FINALLY INSTALLED THE OTHER ABS HCU UNIT THAT WAS SENT TO ME WHEN I ADVISED THE REFURBISHING COMPANY THAT THE DEALER WAS HAVING ISSUES WITH THE FIRST ONE. DEALER ADVISED THAT THEY INSTALLED THE REPLACEMENT ABS HCU AND REPLACED THE BRAKE LINES, AND THE BRAKES STARTED TO WORK LABOR COST $1900.00. I'M GLAD TO BE HERE TO REPORT THIS SAFETY ISSUE THE NEXT PERSON WOULD PROBABLY NOT BE SO LUCKY.
ABS LIGHT ALONG WITH SERVICE BRAKE LIGHT CAME ON WITH NO WARNING RESULTING IN NEAR COMPLETE BRAKE LOSS AND NEARLY STRIKING A PERSON CROSSING THE STREET.
I HAD TO APPLY A PANIC BREAK DUE TO A MOTORCYCLE ACCIDENT IN FRONT OF MY VEHICLE. THE CAR STOPPED BUT THE HYDRAULIC HCU/ECU FOR ABS FAILED AT THE SPOT. I TOOK THE VEHICLE TO THE FORD DEALER AND RECEIVED A 1735.00 PLUS TAX ESTIMATE TO FIX IT.
THIS HAD BEEN A GREAT CAR FOR ME UNTIL TODAY. I LEARNED THE HYDRAULIC CONTROL UNIT IS BAD AND WILL REQUIRE NEARLY $5000 TO REPLACE. IT IS NOT SAFE TO DRIVE. IT HAD 105000 MILES. IT IS NOT WORTH MUCH MORE THAN $5K. I HAVE NO CHOICE BUT TO TRY AND TRADE THE CAR IN. I LATERALLY JUST GAVE IT TO MY DAUGHTER FOR COLLEGE ON SATUR…
Read full complaint
THIS HAD BEEN A GREAT CAR FOR ME UNTIL TODAY. I LEARNED THE HYDRAULIC CONTROL UNIT IS BAD AND WILL REQUIRE NEARLY $5000 TO REPLACE. IT IS NOT SAFE TO DRIVE. IT HAD 105000 MILES. IT IS NOT WORTH MUCH MORE THAN $5K. I HAVE NO CHOICE BUT TO TRY AND TRADE THE CAR IN. I LATERALLY JUST GAVE IT TO MY DAUGHTER FOR COLLEGE ON SATURDAY. SHE HAS ALWAYS LOVED MY CAR.
TL* THE CONTACT OWNS A 2008 MERCURY MARINER. THE CONTACT STATED THAT WHILE DRIVING AT 25 MPH, THE BRAKE PEDAL WAS DEPRESSED BUT FAILED TO STOP THE VEHICLE. THE CONTACT STATED THAT THE BRAKE PEDAL REQUIRED EXCESSIVE PRESSURE TO SLOW THE VEHICLE. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC TO BE DIAGNOSED. THE CONTACT WAS INF…
Read full complaint
TL* THE CONTACT OWNS A 2008 MERCURY MARINER. THE CONTACT STATED THAT WHILE DRIVING AT 25 MPH, THE BRAKE PEDAL WAS DEPRESSED BUT FAILED TO STOP THE VEHICLE. THE CONTACT STATED THAT THE BRAKE PEDAL REQUIRED EXCESSIVE PRESSURE TO SLOW THE VEHICLE. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC TO BE DIAGNOSED. THE CONTACT WAS INFORMED THAT THE BRAKES MASTER CYLINDER NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED HOWEVER, THE FAILURE RECURRED. THE CONTACT ALSO STATED THAT THE BRAKE PADS WERE ALSO REPLACED HOWEVER, THE FAILURE RECURRED. THE CONTACT STATED THAT THE FAILURE OCCURRED ONLY WHEN DRIVING WHILE IT WAS RAINING. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 120,000.
TL* THE CONTACT OWNS A 2008 MERCURY MARINER. WHILE DRIVING APPROXIMATELY 35 MPH, THE BRAKES WERE APPLIED BUT FAILED TO STOP THE VEHICLE. THERE WERE NO WARNING INDICATORS ILLUMINATED. THE FAILURE RECURRED TWICE. THE VEHICLE WAS TAKEN TO THE DEALER WHERE IT WAS DIAGNOSED THAT THE BRAKE PADS, MASTER CYLINDER, AND BRAKE BOOSTER NEED…
Read full complaint
TL* THE CONTACT OWNS A 2008 MERCURY MARINER. WHILE DRIVING APPROXIMATELY 35 MPH, THE BRAKES WERE APPLIED BUT FAILED TO STOP THE VEHICLE. THERE WERE NO WARNING INDICATORS ILLUMINATED. THE FAILURE RECURRED TWICE. THE VEHICLE WAS TAKEN TO THE DEALER WHERE IT WAS DIAGNOSED THAT THE BRAKE PADS, MASTER CYLINDER, AND BRAKE BOOSTER NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE VIN WAS UNKNOWN. THE FAILURE MILEAGE WAS 60,000.
WHILE DRIVING MY CAR STALLS WITHOUT WARNING THEN IT JERKS REAL HARD AND TAKES OFF SO I HAVE TO RIDE THE BRAKES AFTER COMING TO A STOP BEFORE I CAN PRESS THE GAS PEDDLE IT TAKES OFF SO I RIDE THE BRAKES. WHILE DRIVING AGAIN IT PICKS UP SPEED ON ITS OWN VERY SCARE PLEASE HELP. *TR
TOOK VEHICLE TO FORD DEALER TO HAVE CAR INSPECTED WAS TOLD ROTORS HAD TO BE REPLACED DUE TO WEAR BRAKE PADS WERE WEARING UN EVENLY CAR HAS BEEN SERVICED BY DEALER WHEN EVER IT NEEDED INSPECTION OR OIL CHANGES UNEVEN WEAR WASN'T SEEN UNTIL WARRANTY HAD RUN OUT THE CAR HAD LEST THEN 2000 MILES ON SINCE LAST INSPECTION. THIS HAS HA…
Read full complaint
TOOK VEHICLE TO FORD DEALER TO HAVE CAR INSPECTED WAS TOLD ROTORS HAD TO BE REPLACED DUE TO WEAR BRAKE PADS WERE WEARING UN EVENLY CAR HAS BEEN SERVICED BY DEALER WHEN EVER IT NEEDED INSPECTION OR OIL CHANGES UNEVEN WEAR WASN'T SEEN UNTIL WARRANTY HAD RUN OUT THE CAR HAD LEST THEN 2000 MILES ON SINCE LAST INSPECTION. THIS HAS HAPPENED ON OTHER FORD VEHICLES IN PAST PINS THAT BRAKE PADS RIDE ON HAVE ALWAYS BEEN THE CAUSE. THEY ARE CORRODED. *TR
Official recalls
315V606000 · Power Train:automatic Transmission:gear Position Indication (prndl); Power Train:automatic Transmission:lever And Linkage:floor Shift
Sep 29, 2015
Ford Motor Company (Ford) is recalling certain model year 2001-2008 Ford Escape and Mercury Mariner vehicles manufactured March 31, 2001, to September 1, 2009. The affected vehicles are equipped with either a 2.3L or 3.0L engine and have had their CD4E transmission replaced with remanufactured one that was rebuilt between June 11, 2015 through July 15, 2015. These service repair part transmissions have a shift lever bolt that may not be properly tightened. As a result, the shift control lever could disengage from the transmission without warning.
Consequence & remedy
Consequence: If the shift lever disengages from the transmission, a driver may be unable to shift gear positions and the indicated shift position may not represent the gear position the vehicle is in. Should a disengagement occur while the vehicle is being driven, when the driver goes to stop and park the vehicle, the gear selection indicator may show that the transmission is in the "PARK" position, but the vehicle transmission may not actually be in the "PARK" gear position. If the vehicle is not in the "PARK" position there is a risk the vehicle will roll away as the driver and other occupants exit the vehicle or anytime thereafter. A vehicle rollaway increases the risk of injury to exiting occupants and bystanders.
Remedy: Ford will notify owners, and dealers will inspect the transmissions and either tighten the manual shift lever bolt or replace the manual shift lever assembly. These repairs will be performed free of charge. The recall began on October 23, 2015. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 15S28.
Additional source detail variants (2)
Power Train:automatic Transmission:lever And Linkage:floor Shift
Ford Motor Company (Ford) is recalling certain model year 2001-2008 Ford Escape and Mercury Mariner vehicles manufactured March 31, 2001, to September 1, 2009. The affected vehicles are equipped with either a 2.3L or 3.0L engine and have had their CD4E transmission replaced with remanufactured one that was rebuilt between June 11, 2015 through July 15, 2015. These service repair part transmissions have a shift lever bolt that may not be properly tightened. As a result, the shift control lever could disengage from the transmission without warning.
Consequence: If the shift lever disengages from the transmission, a driver may be unable to shift gear positions and the indicated shift position may not represent the gear position the vehicle is in. Should a disengagement occur while the vehicle is being driven, when the driver goes to stop and park the vehicle, the gear selection indicator may show that the transmission is in the "PARK" position, but the vehicle transmission may not actually be in the "PARK" gear position. If the vehicle is not in the "PARK" position there is a risk the vehicle will roll away as the driver and other occupants exit the vehicle or anytime thereafter. A vehicle rollaway increases the risk of injury to exiting occupants and bystanders.
Remedy: Ford will notify owners, and dealers will inspect the transmissions and either tighten the manual shift lever bolt or replace the manual shift lever assembly. These repairs will be performed free of charge. The recall began on October 23, 2015. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 15S28.
Power Train:automatic Transmission:gear Position Indication (prndl)
Ford Motor Company (Ford) is recalling certain model year 2001-2008 Ford Escape and Mercury Mariner vehicles manufactured March 31, 2001, to September 1, 2009. The affected vehicles are equipped with either a 2.3L or 3.0L engine and have had their CD4E transmission replaced with remanufactured one that was rebuilt between June 11, 2015 through July 15, 2015. These service repair part transmissions have a shift lever bolt that may not be properly tightened. As a result, the shift control lever could disengage from the transmission without warning.
Consequence: If the shift lever disengages from the transmission, a driver may be unable to shift gear positions and the indicated shift position may not represent the gear position the vehicle is in. Should a disengagement occur while the vehicle is being driven, when the driver goes to stop and park the vehicle, the gear selection indicator may show that the transmission is in the "PARK" position, but the vehicle transmission may not actually be in the "PARK" gear position. If the vehicle is not in the "PARK" position there is a risk the vehicle will roll away as the driver and other occupants exit the vehicle or anytime thereafter. A vehicle rollaway increases the risk of injury to exiting occupants and bystanders.
Remedy: Ford will notify owners, and dealers will inspect the transmissions and either tighten the manual shift lever bolt or replace the manual shift lever assembly. These repairs will be performed free of charge. The recall began on October 23, 2015. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 15S28.
14V526000 · Hybrid Propulsion System
Sep 3, 2014
Ford Motor Company (Ford) is recalling certain model year 2005-2008 Ford Escape hybrid electric vehicles manufactured October 13, 2003, to June 20, 2008, and 2006-2008 Mercury Mariner hybrid electric vehicles manufactured June 10, 2005, to June 20, 2008. The coolant pump for the hybrid system may fail resulting in the hybrid electronics overheating.
Consequence & remedy
Consequence: If the hybrid electronics system overheats, it may shut down the powertrain, resulting in a stall-like condition, increasing the risk of a crash.
Remedy: Ford will notify owners, and dealers will inspect and replace the original Motor Electronics Coolant (MEC) Pump with an improved brushless pump, free of charge. The recall is expected to begin on October 27, 2014. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 14S19.
14V284000 · Steering:electric Power Assist System
May 29, 2014
Ford Motor Company (Ford) is recalling certain model year 2008-2011 Ford Escape and Mercury Mariner vehicles manufactured August 18, 2006, through September 11, 2010. The affected vehicles have a steering torque sensor that may not be able to properly detect driver steering input. As a result, the system could remove the Electric Power Steering (EPS) assist.
Consequence & remedy
Consequence: If power steering assist is lost, greater driver effort would be required to steer the vehicle at low speeds, increasing the risk of a crash.
Remedy: Ford will notify owners, and dealers will update the software for the power steering control module (PSCM) and the instrument cluster module, free of charge. If a vehicle shows a history of a loss of the torque sensor signal or fault codes relating to the PSCM when the vehicle is brought in for the recall remedy, the affected components will be replaced, free of charge. The recall began on July 18, 2014. Owners may contact Ford customer service at 1-800-392-3673. Ford's number for this recall is 14S05.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
2DP15001 · Loss Of Power Steering While Driving
Opened Apr 1, 2015 · Closed Jun 14, 2018
Status: closed (inferred from source dates) · Steering:electric Power Assist System
On May 27, 2014, amended June 2, 2014, Ford Motor Company (Ford) submitted a Defect Information Report (DIR) to NHTSA describing a safety defect that may result in a sudden loss of power steering assist while driving in approximately 746,067 model year (MY) 2008 through 2011 Ford Escape vehicles equipped with electric power assisted steering (NHTSA 14V-284, Ford 14S05). Ford's DIR described the defect condition as a poor signal to noise ratio [SNR] in the torque sensor within the Electric Power Assisted Steering (EPAS) system [which] does not allow the PSCM to determine the driver's steering input. When the system detects this fault condition, it transitions the EPAS system to the fail-safe/manual steering mode.Ford's DIR indicates that loss of power steering assist while driving would require higher steering effort at lower vehicle speeds, which may result in an increased risk of a crash.Ford's remedy instructs dealers to check the Power Steering Control Module (PSCM) for Diagnostic Trouble Codes (DTCs) to determine the proper repair procedure. If no DTCs are present, dealers are to update the PSCM and instrument cluster module software. The updated PSCM software changes the torque sensor fault strategy so that the SNR condition does not result in a loss of power steering assist while driving.In addition, audible and visual warnings are provided for torque sensor faults.If DTCs indicating faults in the torque sensor, PSCM or Power Steering Motor (motor) are present in the initial recall inspection, the dealer performs the following repairs: 1) replaces the torque sensor for torque sensor faults (DTC B2278); or 2) replaces the steering column for faults related to the PSCM (DTC B1342) or motor (DTC B2277).Continued in attachment pages
PE08060 · Tire Valve Cracking
Opened Oct 14, 2008 · Closed Apr 9, 2009
Status: closed (inferred from source dates) · Tires:valve
ON OCTOBER 14, 2008, ODI OPENED PE08-060 TO INVESTIGATE ALLEGATIONS OF CRACKED AND LEAKING SNAP-IN TIRE VALVES IN MODEL YEAR (MY) 2007 VEHICLES MANUFACTURED BY FORD MOTOR COMPANY.THE VALVES WERE SUPPLIED TO FORD BY TOPSEAL AUTO-PARTS, A SUBSIDIARY OF THE SHANGHAI BAOLONG AUTOMOTIVE CORPORATION IN CHINA.VALVES MADE BY TOPSEAL FOR AFTERMARKET SALE WERE THE SUBJECT OF TWO RECENT SAFETY RECALLS BY TECH INTERNATIONAL (08T-018) AND DILL AIR CONTROLS (08T-028), THE LATTER OF WHICH WAS INVESTIGATED BY ODI IN PE08-036 AND EA08-022.THE DEFECT CONDITIONS ADDRESSED BY THE AFTERMARKET TIRE VALVE RECALLS BOTH INVOLVED INADEQUATE RESISTANCE TO OZONE CRACKING DUE TO ISSUES WITH THE SUPPLY OF ANTI-OZONANT CHEMICALS TO TOPSEAL FOR A PERIOD FROM JULY TO MID-NOVEMBER 2006.THE AFTERMARKET VALVES WERE COMPOUNDED WITH A BLEND OF EPDM AND NATURAL RUBBER, USING A RELATIVELY LOW PERCENTAGE OF EPDM (EPDM PROVIDES INHERENT RESISTANCE TO OZONE CRACKING).HENCE, THE NEED FOR ANTI-OZONANT CHEMICALS AND THE PROBLEMS WITH CRACKING WHEN THOSE CHEMICALS WERE MISSING OR OUT OF SPECIFICATION IN SOME LOTS OF VALVES.BOTH RECALL CAMPAIGNS INVOLVED INSPECTION PROGRAMS TO IDENTIFY AND REPLACE VALVES WITH VISIBLE SURFACE CRACKING.ALTHOUGH THE TOPSEAL VALVES SUPPLIED TO FORD ALSO APPEAR TO HAVE BEEN AFFECTED BY THE ANTI-OZONANT SUPPLY ISSUES IN MID TO LATE-2006, FORD INDICATED THAT ITS VALVES WERE MADE AT A DIFFERENT TOPSEAL PRODUCTION LINE AND WERE COMPOUNDED WITH A HIGHER PERCENTAGE OF EPDM RUBBER TO MEET MORE STRINGENT SPECIFICATIONS FROM FORD.ODI'S ANALYSIS OF COMPLAINT AND WARRANTY DATA PROVIDED BY FORD SHOWED THAT PROBLEMS WITH CRACKED TIRE VALVES WERE SIGNIFICANTLY HIGHER FOR MY 2007 VEHICLES PRODUCED FROM DECEMBER 2006 THROUGH MARCH 2007.FORD RESPONDED BY IMPLEMENTING CHANGES IN ITS MATERIAL SPECIFICATIONS FOR SNAP-IN RUBBER TIRE VALVES AND ALSO INCREASING THE QUALITY AND ACCEPTANCE STANDARDS FOR VALVES IMPORTED FOR USE IN ITS VEHICLES.WHILE THE COMPLAINT AND WARRANTY CLAIM RATES ARE ELEVATED FOR SUBJECT VEHICLES PRODUCED FROM DECEMBER 2006 THROUGH MARCH 2007, THE RATES OF LEAKING VALVES ARE WELL BELOW ONE PERCENT OF PRODUCTION FOR EACH OF THE PEAK MONTHS FOR ALL OF THE AFFECTED MODELS.A SUBSTANTIAL MAJORITY OF THE SUBJECT VEHICLES ARE EQUIPPED WITH TIRE PRESSURE MONITORING SYSTEMS (TPMS) WHICH WARN THE DRIVER WHEN ANY TIRE PRESSURES DROPS BELOW 25 PERCENT OF RECOMMENDED INFLATION PRESSURE. AS OUTLINED IN A LETTER TO ODI DATED APRIL 6, 2009, FORD HAS AGREED TO SEND LETTERS TO OWNERS OF CERTAIN MY 2007 AND 2008 FORD, LINCOLN AND MERCURY VEHICLES TO PROVIDE INFORMATION ABOUT THE CRACKING CONCERN. LETTERS WILL BE SENT TO OWNERS OF VEHICLES BUILT FROM NOVEMBER 2006 THROUGH MAY 2007.OWNERS CAN OPT FOR A FREE DEALER INSPECTION.VALVES EXHIBITING SURFACE CRACKS OR AIR LEAKAGE RELATED TO OZONE ATTACK WILL BE REPLACED BY FORD UNDER ITS NORMAL WARRANTY TERMS.FORD EXPECTS TO SEND THE LETTER BY APPROXIMATELY MID-MAY 2009. BASED ON THE USE OF TPMS IN THE MAJORITY OF SUBJECT VEHICLES AND THE RELATIVELY LOW RATES OF REPAIRS ASSOCIATED WITH LEAKING VALVES AND RESULTANT TIRE DAMAGE, ODI BELIEVES THAT THE ACTIONS FORD HAS AGREED TO TAKE WILL PROVIDE EFFECTIVE AND EXPEDITIOUS RESOLUTION FOR VEHICLES THAT WERE BUILT DURING THE PERIOD WHEN VALVES WITH INADEQUATE RESISTANCE TO OZONE CRACKING WERE MOST LIKELY TO HAVE BEEN USED IN VEHICLE PRODUCTION.FURTHER INVESTIGATION OF THIS MATTER WOULD NOT BE AN EFFICIENT ALLOCATION OF AGENCY RESOURCES.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST.THE AGENCY WILL CONTINUE TO