Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Jeep Wrangler owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2012 Jeep Wrangler. The contact stated while starting the vehicle, there was an abnormal burning odor around the vehicle. The contact stated while driving 45 MPH and other various speeds the burning odor was still present. The check engine warning light illuminated with the temperature gauge rising from normal to hot. An audible alarm was heard during the failure. The vehicle was driven to the residence and then towed to a dealer. The vehicle was diagnosed and determined that the radiator needed to be replaced. The contact had the vehicle towed to an independent mechanic who determined that coolant was leaking into the cylinder head. The vehicle had not been repaired. The manufacturer had been informed of the failure. The failure mileage was approximately 60,000.
The contact owns a 2012 Jeep Wrangler. The contact stated that while operating the vehicle the ABS, Traction Control and check engine warning lights had remained illuminated. The contact indicated that while pressing the brake pedal to stop, the brake pedal extended to the floor causing the braking distance to become extended. The vehicle was taken to the local dealer who diagnosed that the ABS module was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure but no assistance was offered. The failure mileage was 55,000.
The contact owns a 2012 Jeep Wrangler. The contact stated that the engine would misfire while driving at various speeds. Due to the failure, the vehicle would independently go into limp mode with the traction control and check engine warning lights illuminated. The contact had taken the vehicle to several unknown dealers and the engine misfire was acknowledged however, the cause of the failure was not determined. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 90,000. The VIN was not available.
The contact owns a 2012 Jeep Wrangler. The contact stated that while driving at 20 MPH, the check engine warning light illuminated. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The vehicle was taken to an independent mechanic, where a scan was completed, and diagnostic trouble codes for the Emissions, engine misfire, timing chain, and crank position sensor failures were displayed. The manufacturer was not contacted. The failure mileage was approximately 71,756.
I was driving on the highway and the engine caught fire. I've been looking for an engine to rebuild and all of them had previously been on fire. I believe the engine is defective for the jeeps that year, make and model.
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. …
In my 2012 Jeep I had to replace the engine and catalytic converters. The engine number 3 cylinder failed due to excessive ware causing lower compression. After the engine (long block) was replaced, one of the cylinders was miss firing. This miss firing was traced to micro cracks in the plastic/composite intake manifold (original and not part of the engine replacement). Because these micro cracks changed the fuel air ratio on specific cylinders by leaning out the cylinders near the cracks this lean mixture would cause the affected cylinders to run hot that would lead to both the excessive ware on the one cylinder and would comprise the catalytic converters. …
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.
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.
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.
Engine complaints in other Wrangler years
Frequently asked questions
How common are engine problems on the 2012 Jeep Wrangler?
NHTSA has 178 complaints about the engine & cooling of the 2012 Jeep Wrangler, 21% of the model year's 835 complaints. The component named most often is exhaust system › manifold/header/muffler/tail pipe (1 mentions).
Is there a recall for 2012 Jeep Wrangler engine problems?
No. NHTSA lists no engine & cooling recall for the 2012 Jeep Wrangler, though it has 9 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2012 Jeep Wrangler engine problems start?
Half of the complaints with a recorded mileage happened before about 40,000 miles, and 39% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 11 fires and 3 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.