On vehicles equipped with an automatic transmission it is imperative that the converter pilot hub be greased with Motorcraft Multi-Purpose Grease Spray XL-5-A even if grease was not applied from the factory. Also verify that the engine/transmission alignment dowel pins are present as well as the engine crankshaft dowel pin, if equipped, when installing the transmission. Failure to adequately lubricate the converter hub greatly increases the likelihood of the flexplate cracking in the future. Missing dowels may cause a misalignment issue also resulting in a premature failure. Refer to Workshop Manual (WSM), Section 307-01.
full bulletin at NHTSA ↗2011 Ford Flex powertrain problems
moderate 18 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
18
Recalls
0
Avg fix
$2,500
When does it fail?
Of the 18 powertrain complaints filed for the 2011 Ford Flex, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Among the 8 model years of Ford Flex in our records for powertrain problems, this one ranks #2 by owner-complaint volume.
No new NHTSA powertrain complaint has been filed on this vehicle in over 3 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
FORD: IF THERE IS AN INTERMITTENT LACK OF POWER, SURGE, OR HESITATION WHILE DRIVING THE BRAKES WILL OVERRIDE ACCELERATION.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2011 Ford Flex powertrain shows multiple distinct failure patterns. PTU (power transfer unit) overheating and fluid leaks are the most consistent complaint—owners report burning oil smell starting around 50k miles, escalating to leaks and failures at 59k–120k miles. Repair costs run $1600–$1888, and owners cite multiple forums documenting the same issue across Flex, Edge, Taurus, and MKT models. Ford treats the PTU as non-serviceable (replacement only) with no maintenance schedule, yet refuses warranty coverage when failures occur after extended warranty expires, even if symptoms began under warranty.
Transmission problems are equally widespread: owners describe hesitation or neutral-feeling takeoff from stops, followed by violent lurching into gear. This bang-into-gear defect appears intermittent over months or years, with dealers unable to reproduce or fix it despite existing TSBs for similar 2011 transmission issues.
Additional reported failures include water pump and rear main seal leaks causing engine failure, throttle body replacement that didn't resolve limp mode, transmission filler cap defects (O-ring too large) allowing fumes into cabin, and shifter bushing disconnect leaving vehicles stuck in drive. Brake lockup with cascading front-end component failures and sensor failures are reported, sometimes at mileages as low as 30k–60k miles.
Same Ford Flex powertrain reports on nearby years: 2009 · 2010
Failure modes owners describe
PTU (Power Transfer Unit) overheating and fluid leak
The power transfer unit fails due to overheating, causing fluid to leak. Owners report that the unit is designed as non-serviceable by Ford (replacement only, no maintenance schedule), yet multiple units fail under normal driving conditions. Owners cite burning oil smell before diagnosis, and fluid leaks at 50k–85k+ miles. Repair costs are cited as $1600–$1888.
When: 50k–85k+ miles (varies; 59k miles in narrative #1; 120k highway miles in narrative #6)
Symptoms owners cite: Burning oil smell after highway driving; Fluid leak; Overheating of unit
Repairs/costs cited: PTU replacement; costs cited $1600–$1888. No maintenance intervals offered by Ford.
Recalls/TSBs owners mention: Ford refuses warranty coverage when failures occur after extended warranty expiration, even if symptoms began during warranty period. No proactive service bulletins or recalls issued despite reported pattern across Ford AWD vehicles (Flex, Edge, Taurus, MKT, Explorer).
Transmission hesitation, neutral-to-gear lurch, and bang-into-gear
Transmission exhibits hesitation or acts as if in neutral when accelerating from a stop, then suddenly 'bangs' or lurches violently into gear. Owners report this happens intermittently over months or years. Multiple owners link the issue to existing TSBs and forum discussions but Ford dealers cannot diagnose or fix the problem.
When: Reported from 52k miles; intermittent across years of ownership
Symptoms owners cite: Engine revs with no forward movement from a stop; Violent lurch or bang when transmission engages; Hesitation during acceleration from stop; Slips and bangs into 1st or 2nd gear
Repairs/costs cited: No repairs successfully completed; dealers report no fault codes found and no solution offered.
Recalls/TSBs owners mention: Ford unable to resolve despite multiple dealer visits. TSBs exist for same transmission issues in 2011 build cars but have not resolved complaints.
Unintended acceleration and stalling (EcoBoost system)
Vehicle accelerates without operator input or stumbles/stalls when accelerating from a stop or at highway speeds. Owner reports the vehicle will 'almost stall, then speed up without your foot on the pedal,' producing black smoke. Module re-flashing by dealer did not resolve the issue. Owner reports vehicle reaching 2000 RPM without pedal input while driving.
When: Occurred over several months; vehicle had extended warranty when issue began
Symptoms owners cite: Almost stalls then speeds up without foot on pedal; Black smoke emission; Vehicle revs to 2000 RPM without pedal input; Check engine light and wrench light illumination
Repairs/costs cited: Module re-flashing attempted but did not resolve. No successful repair noted.
Recalls/TSBs owners mention: Dealer re-flashed modules after diagnosis; failure persisted.
Throttle body failure (recurrent)
Two narratives report throttle body replacement that failed to resolve limp mode and rough driving symptoms. In one case, throttle body was replaced twice before dealer diagnosed water pump and rear main seal failure as underlying cause.
When: Reported at 112k miles in one case; timing unspecified in second case
Symptoms owners cite: Vehicle enters limp mode; Check engine light illumination; Rough driving; Abnormal clunking sound
Repairs/costs cited: Throttle body replaced twice in one vehicle without resolution. In same vehicle, water pump replacement and rear main seal leak led to engine failure.
Recalls/TSBs owners mention: Manufacturer notified; case number provided but vehicle not repaired.
Water pump failure and rear main seal leak
Water pump fails, allowing radiator fluid to leak from rear main seal, causing engine failure. Described as failure of previously replaced water pump.
When: ~112k miles
Symptoms owners cite: Antifreeze leaking from vehicle; Radiator fluid leaking from rear main seal
Repairs/costs cited: Water pump previously replaced; failure recurred. Engine failure resulted from seal leak.
Recalls/TSBs owners mention: Manufacturer notified; case number provided but vehicle not repaired.
Transmission filler cap and O-ring defect
Transmission filler cap O-ring is oversized, allowing transmission fumes to enter cabin during high-speed acceleration. Causes nausea and eye burning in occupants.
When: 1,500 miles; diagnosis at 9,000 miles
Symptoms owners cite: Fumes entering cabin with vents closed; Nausea and burning eyes
Repairs/costs cited: Transmission filler cap replaced (O-ring was too large).
Transmission shifter bushing disconnect
Shifter bushing disconnects from transmission, allowing shifter to move without engaging gears. Vehicle remains in drive even when shifted to reverse or park. Owner notes this part is subject to recall on other Ford vehicles but not recalled for Flex.
When: Mileage not specified
Symptoms owners cite: Shifter disconnected from transmission; Vehicle continues forward when shifted to reverse or park; Transmission stuck in drive
Repairs/costs cited: Transmission shifter bushing disconnection identified; repair not described.
Recalls/TSBs owners mention: No recall issued for 2011 Flex despite same part being recalled on other Ford vehicles.
Power steering assist failure
Power steering loses assist, making steering extremely difficult or impossible. Owner reports dinging alert and 'power steering assist failure' warning. Dealership disputes coverage despite owner noting a clear recall match for vehicle year.
When: Mileage not specified
Symptoms owners cite: Continuous dinging; Power steering assist failure warning; Loss of steering assist; steering extremely difficult
Recalls/TSBs owners mention: Ford recall issued matching vehicle year; dealership disputes coverage.
Brake system lockup (rear and front end component failures)
Rear brakes lock suddenly, immobilizing vehicle in traffic. Front-end components fail shortly after, including wheel bearings, CV joints, tie rods, CV axles, CV boots, and sway bars. Owner reports sensors fail immediately, causing brake warnings without warning and power steering module failure. Multiple owners of 2011 Flex report same pattern even with low mileage (30k–60k miles).
When: 30k–60k miles reported for sensor failures; mileage for brake lockup and front-end failures not specified
Symptoms owners cite: Rear brakes lock up suddenly; Front-end component failures: wheel bearing, CV joint, tie rod, CV axle, CV boot, sway bar; Sensors fail (multiple sensors); Check engine light; Power steering module failure; Vehicle stutter
Repairs/costs cited: Extensive front-end repairs needed; costs cited as expensive and unaffordable for complainant.
Recalls/TSBs owners mention: No recall issued despite multiple owners reporting identical pattern.
Synthesized from 18 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
The contact owns a 2011 Ford Flex. The contact stated that while driving at various speeds, the check engine warning light and wrench light illuminated, and the vehicle started driving rough. The contact stated that the vehicle decelerated and then failed to properly accelerate. The vehicle was taken to the local mechanic who replaced the throttle body, but the failure persisted. The vehicle was…
Transmission on flex often hesitates and thunks with a lurch. The lurch is so bad it now feels like we are being hit. It has happened in both forward and reverse. Tried to get it repaired twice at dealer - haven't been able to fix. Online forums with owners and service bulletins describe similar problem. Ford not acknowledging issue or helping. *tr
Had powertrain trouble with your 2011 Ford Flex?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2011 Ford Flex?
It's a documented issue but not catastrophic. 18 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Across the 14 complaints that reported odometer mileage, most powertrain failures cluster between 5,200 and 120,000 miles, with the median around 58,195. A quarter of owners report trouble before 5,200; a quarter make it past 120,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2011/Ford/Flex.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.