2009 Mercury Mariner Engine Problems

NHTSA component category: ENGINE · data through 07/12/2026

53Engine complaints

16.8%Of all 315 complaints

#2Most-reported category

Source: U.S. NHTSA complaint data. Complaints are unverified reports from vehicle owners — a complaint is not a confirmed defect.

How engine ranks on this vehicle

STEERING166 · 52.7%

ENGINE53 · 16.8%

VEHICLE SPEED CONTROL41 · 13%

POWER TRAIN41 · 13%

ELECTRICAL SYSTEM21 · 6.7%

Share of the 315 complaints citing each category; one complaint can cite several. Full breakdown on the 2009 Mercury Mariner overview page.

What owners report

“THE VEHICLE SUDDENLY LOOSES POWER AND ACCELERATOR IS UNRESPONSIVE. THIS FIRST OCCURRED WITH APPROXIMATELY 33,000 MILES WHILE STILL IN WARRANTY AND DEALER REPLACED THROTTLE BODY…”NHTSA complaint 10558529 — filed 01/05/2014

“WHILE DRIVING, THE VEHICLE STARTED LOSING POWER AND THE WRENCH LIGHT CAME ON; STOPPED AND HAD A HARD TIME CRANKING BUT WAS ABLE TO GO…”NHTSA complaint 10558442 — filed 01/04/2014

“WHEN PULLING UP TO A STOP SIGN THE CAR JUST STOPPED NEXT TIME COMING OFF INTERSTATE TO STOP THE VEHICLE KINDA OF LUNGED THE NEXT…”NHTSA complaint 10557514 — filed 12/28/2013

Excerpts are shortened and scrubbed of personal details; they are individual, unverified reports.

Engine complaints by year filed

Frequently asked questions

Does the 2009 Mercury Mariner have engine problems?

Engine is the #2 most-reported problem area on the 2009 Mercury Mariner: 53 of 315 complaints on file (16.8%). Complaints are unverified owner reports, not confirmed defects.

How many complaints does the 2009 Mercury Mariner have in total?

315 complaints were on file with NHTSA as of 07/12/2026. Across all categories, 9 involved a crash, 0 involved a fire, 3 reported injuries, and none reported deaths.

What does NHTSA's engine category include?

NHTSA assigns each complaint to standard component categories; this page reports the ENGINE category exactly as NHTSA defines and records it.

About this data — Complaint figures on this page are consumer reports submitted to the National Highway Traffic Safety Administration (NHTSA), a U.S. government agency. NHTSA does not verify individual complaints; a complaint is not proof that a defect exists, and counts reflect what owners chose to report, not confirmed failure rates. Recall information comes from official NHTSA safety recall campaigns; recall repairs are free at authorized dealers. Always check your specific vehicle by VIN at nhtsa.gov/recalls. CarModelProblems.com is an independent site and is not affiliated with NHTSA or any vehicle manufacturer. Data through 07/12/2026.