2012 Jeep Wrangler Engine Problems

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.

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.

Timing chain and misfire bank 1 and bank 2 crank shaft and crank sensor issues.

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.

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 NHTSA 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.

Engine spontaneously caught fire. It had been parked for hours before it happened. Everything under the hood was totaled

6 days after an oil change, the temp gauge while driving went from cool to hot in under a mile and the engine temp light came on. There was coolant all over the underside of the car it was near catastrophic. I had to have it towed to the dealership for repairs. The faulty part was the oil filter adapter it was cracked by over tightening of the oil filter.

Jeep Wrangler 3.6 liter 90k miles lifter making loud noise. Seems you had a recall about this on the 2012 and guess I missed out

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. Because this change in fuel air mixture was caused by the intake manifold and Jeep does not have any inspection requirements or methods for this item and even after the Jeep Dealer did a full diagnosis using their factory specified equipment the issue with the manifold was not found. My local AMMCO shop found the cracking in the manifold that was the route cause of the problem.

CAM SENSOR FAILED. CHECK ENGINE LIGHT AND TRACTION CONTROL LIGHT APPEARED. REPLACED AND SAME PROBLEMS OCCURRED. MAY BE WIRING OR CAM/ROCKER ISSUES.

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.

OIL COOLER CRACKED AND LEAKING ANTIFREEZE ALL OVER ENGINE AND UNDER FRAME. ANTIFREEZE IN THE OIL. ONLY 69K MILES ON THE VEHICLE. THIS IS A REALLY BIG PROBLEM WITH THESE OIL COOLERS ON JEEPS AND SHOULD BE RECALLED. COST TO REPLACE IS VERY EXPENSIVE!!

OIL COOLER BROKE AND STARTED LEAKING AFTER THE COLD TEMPERATURE IN OKLAHOMA ON 2/14/21

THE OIL COOLER FAILING, LEAKING. I HAVE JUST DISCOVERED THAT MY OIL COOLER IS LEAKING FROM A PUDDLE ON THE GROUND AND MY LOWER ENGINE FULL OF OIL. I GOT NO WARNING LIGHT. IF THERE HAD NOT BEEN A NOTICABLE PUDDLE I WOULD HAVE NEVER NOTICED IT. IF NOT MY MOTOR WOULD HAVE LOCKED UP AND WOULD NEED TO BE REPLACED. I CHECKED MY OIL LEVEL AND NO OIL IS ON THE DIPSTICK. I HAVE DONE RESEARCH AND FOUND THAT THIS IS A VERY BIG PROBLEM IN THE JEEP COMMUNITY. I STRONGLY FEEL THAT THIS SHOULD BE RECALLED AND REPAIRED. IF IT WAS A HERE AND THERE INCIDENT, IT WOULD B DIFFERENT. BUT IT'S A VERY BIG PROBLEM. IN THE PHOTO LOOK TO THE LEFT OF THE OIL FILTER HOUSING. IT'S A PUDDLE OF OIL. THE PRICE OF OIL IS NOT CHEAP. NEITHER IS THE TIME CONSUMING AND COST OF THE REPAIR. PLEASE ADD THIS TO THE RECALLS FOR THIS VEHICLE.

OIL LEAKING OFF TOP OF ENGINE. CRACKED PLASTIC PART CAUSED OIL TO LEAK OUT ON ENGINE AND EXHAUST CREATING A BURNING SMELL AND MY MECHANIC SAID IT IS A FIRE HAZARD. FOUND MANY OTHERS WITH SAME ISSUE FROM JEEP AND CHRYSLER PRODUCTS.

OIL LEAKING FROM ENGINE. MECHANIC SAID COULD BE DANGEROUS AS IT WAS GETTING ON THE EXHAUST AND COULD START A FIRE. DOING RESEARCH ON THIS WEBSITE, FOUND OUT IT IS A COMMON PROBLEM WITH A PLASTIC PART ON TOP OF THE ENGINES USED BY JEEP AND CHRYSLER. THIS SHOULD BE RECALLED.

WHILE DRIVING ENGINE LOOSES POWER AND VIBRATES EXCESSIVELY, ENGINE LIGHT FLASHES DURING THIS PROCESS, AFTER ABOUT 30 SECONDS LIGHT GOES OUT AND ENGINE RESUMES NORMAL OPERATION. IT HAS DONE THIS MULTIPLE TIMES SOMETIMES ON STARTUP SOMETIMES STOPPED AT A LIGHT AND OTHER WHILE DRIVING.

THE LIFTERS (HEADERS) HAVE GONE BAD. INCREDIBLE TICKING NOISE FROM THE ENGINE IN DRIVE AND IDLE. AS RPMS INCREASE THE TICKING IS LOUDER. THE ONLY WAY TO FIX IS TO REPLACE THE HEADERS. I HAVE READ A MULTITUDE OF COMPLAINTS ON THE NHTSA PAGE REGARDING THIS AND ADDITIONAL COMPLAINTS ALL OVER JEEP FORUMS THAT THIS IS A KNOWN ISSUE WITH THE 2012 ENGINES ... WHY IS THIS NOT BEEN RECALLED?

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.

TRANSMISSION FULL OF ANTIFREEZE. INTERNAL TRANSMISSION COOLER (IN RADIATOR) FAILED. CAUSED TRANSMISSION TO FAIL. *TR