2012 Jeep Wrangler: sudden loss of power

Filed Nov 1, 2026 · Engine · TN

While driving my 2012 Jeep Wrangler Sport, the vehicle experienced a sudden and severe loss of engine power due to a cylinder failure on the left/driver-side cylinder head (cylinder #2). This defect causes the engine to experience persistent cylinder misfires, resulting in severe engine stumbling, hesitation, and a dangerous drop in acceleration capabilities. This creates an immediate safety hazard when attempting to merge onto high-speed highways, pull out into active traffic, or navigate intersections, as the vehicle cannot accelerate predictably to match traffic speeds. Furthermore, the persistent misfire causes unburned fuel to dump into the exhaust system, creating a secondary risk of catalytic converter overheating, damage to the exhaust system, and a potential engine bay fire hazard. This vehicle has only 86,000 original miles. This specific 3.6L Pentastar engine generation is subject to a widely documented manufacturing defect involving premature valve seat and head failure, which manifests as an unpredictable and sudden loss of motive power while the vehicle is in motion.

Filed Oct 29, 2025 · Engine · CA

The vehicle exhibits a persistent valvetrain ticking noise associated with the rocker/lifter/cam components of the 3.6L Pentastar V6. The engine makes a rhythmic metallic tapping at idle and during acceleration. The noise has progressively worsened, leading to rough idle and occasional misfires. This issue is documented in multiple Stellantis technical service bulletins (e.g., TSB 09-015-24 and TSB 09-011-25) which attribute the noise to hydraulic lash adjuster and cam/rocker wear. If unaddressed, the failure can cause camshaft damage, metal debris contamination, loss of power and potential engine stall, posing a safety risk. The vehicle is available for inspection. The problem has been confirmed by independent mechanics who recommend replacement of the rocker arms, lifters and camshaft to prevent catastrophic engine failure.

Filed Sep 30, 2025 · Engine · MO

The vehicle exhibits a persistent valvetrain ticking noise associated with the rocker/lifter/cam components of the 3.6L Pentastar V6. The engine makes a rhythmic metallic tapping at idle and during acceleration. The noise has progressively worsened, leading to rough idle and occasional misfires. This issue is documented in multiple Stellantis technical service bulletins (e.g., TSB 09-015-24 and TSB 09-011-25) which attribute the noise to hydraulic lash adjuster and cam/rocker wear. If unaddressed, the failure can cause camshaft damage, metal debris contamination, loss of power and potential engine stall, posing a safety risk. The vehicle is available for inspection. The problem has been confirmed by independent mechanics who recommend replacement of the rocker arms, lifters and camshaft to prevent catastrophic engine failure.

Filed Jun 6, 2025 · Engine · IL

I am reporting a persistent and safety-relevant defect in my 2012 Jeep Wrangler with the 3.6L Pentastar engine. The vehicle is experiencing misfires on multiple cylinders, especially cylinders 1 and 5, triggering codes P0300, P0301, and P0305. These misfires result in loss of power, hesitation, and rough idle, creating serious safety concerns during acceleration or highway driving. Despite replacing spark plugs, ignition coils, the crankshaft position sensor, purge valve, and both oxygen sensors, the problem continues. The vehicle has just 83,000 miles and is currently at a certified third-party repair facility. Multiple mechanics believe the issue stems from known defects in the left (Bank 1) cylinder head or valve train components—an issue Chrysler previously acknowledged via TSBs and a 10yr/150k mile extended warranty on select VINs. I contacted Jeep Cares and requested goodwill support, but they refused to even discuss the issue because my Jeep is not at a dealership. This leaves owners like me with limited, expensive options despite being affected by a well-documented defect. Jeep forums and independent shops have seen widespread misfire problems on early 3.6L Pentastar engines, especially 2012-2013 models. I urge the federal safety agency to investigate this pattern of failure. The misfires impact driveability and safety, and the manufacturer has not offered sufficient resolution or consistent support to affected customers. I’m happy to provide additional information, documentation, or diagnostics.

Filed Apr 4, 2023 · Engine, Fuel system · VA

Engine Stalls Randomly while Driving. Will crank over several times and over approx 10-15 min. of cranking(Say every 3-5min) vehicle will and will restart. No check engine lights and no warning. The loss of power can be dangerous since brake and steering assist require engine to be running. Vehicle will be fine for several days local commute and problem will recur without warning, usually on longer commute. Vehicle is unsafe and unpredictable.

Filed Jul 12, 2022 · Engine, Transmission · WI

While driving the car randomly stalls. I lose power steering and braking. The car will not restart. This issue has been recorded by the dealer. The vehicle was last inspected on July 5th. I have been issued a Jeep Care case manager, case # 82963828. There are no warnings, while driving makes a left-hand turn the car just stalls!

Filed Jul 4, 2022 · Electrical, Engine · WI

Starting out at a stop light, engaging the clutch to start moving, I depressed the clutch to shift into second gear while making a turn, the vehicle stalls, losing all power.

Filed Jul 4, 2022 · Electrical, Engine · WI

Starting out at a stop sign. engaging the clutch to start moving, while shifting into 2nd gear while turning the vehicle stalls. Losing all power steer and brakes. I try to re-start the car i get a crank no-start scenario. Wait 3-5 min, retry starting the vehicle starts.

Filed Jul 4, 2022 · Engine, Fuel system · WI

While driving making a turn, shifting from 1st to 2nd gear, and vehicle stalls losing all power. The vehicle has been to the deal multiple times and the issue can not be duplicated. The vehicle has been inspected multiple times and there are no known issues. No-fault codes are thrown. I stalled in the middle of a busy intersection, with my children in the car. I had to push the vehicle to safety!

Filed Jul 4, 2022 · Electrical, Engine · WI

While driving making a turn, shifting from 1st to 2nd gear, and vehicle stalls losing all power. I had a crank no-start scenario! The vehicle has been to the deal multiple times and the issue can not be duplicated. The vehicle has been inspected multiple times and there are no known issues. No-fault codes are thrown. I was able to cost to a safe location, and wait. after 3-5 min the vehicle restarted.

Filed Jul 4, 2022 · Electrical, Engine · WI

While driving making a turn, shifting from 1st to 2nd gear, and vehicle stalls losing all power. I had a crank no-start scenario! The vehicle has been to the dealer multiple times and the issue can not be duplicated. The vehicle has been inspected multiple times and there are no known issues. No-fault codes are thrown. I was able to cost to a safe location, and wait. after 3-5 min the vehicle restarted.

Filed May 28, 2022 · Engine, Fuel system · WI

While driving the car stalled. Loss of power steering and braking. I was able to coast to a safe location. I tried to restart, but Crank- No Start.