Jeep Wrangler JL Review: Problems, Reliability & Buying Guide

The fourth generation Jeep Wrangler (JL) represents a fundamental rethinking of the legendary off-road vehicle. While previous generations were renowned for their simple construction, minimal electronics, and reliable naturally aspirated engines, the new generation has taken the path of maximum adaptation to modern realities. Manufacturers have packed the vehicle with complex electronics and introduced a compact turbocharged engine under the hood.

History and Model Characteristics

The fourth generation Wrangler was introduced in November 2017 in Los Angeles, and serial production began immediately. The new generation off-roader differs dramatically from its predecessors not only externally but also technically.

Of the five possible powertrains (three gasoline and two diesel), several key variants gained the most widespread adoption. The most popular became the two-liter turbocharged gasoline Hurricane GME-T4 engine, working in tandem with an eight-speed automatic transmission ZF 8HP (also known as TorqFlite 850RE).

Hurricane GME-T4 2.0 Liter Engine

General Characteristics

The Hurricane GME-T4 represents a relatively young turbocharged engine that appeared in 2016. This motor became the first representative of the Global Medium Engine family and remains available only in two-liter displacement with various power configurations.

Notably, the fourth generation Jeep Wrangler became the first vehicle to receive this engine, which naturally affected the initial reliability of the powerplant.

Early Production Period Problems

Owners of first-year vehicles encountered characteristic teething problems typical of new engines. The most frequent issue was Check Engine light illumination on practically new cars with only a few hundred or thousand kilometers on the odometer.

The causes of this phenomenon were diverse:

• Loose wiring
• Defective sensors
• Loose terminals and contacts
• Insufficient quality control during assembly

All this pointed to serious gaps in the technological production process of the new and sufficiently complex engine.

Cooling System Problems

One of the most significant factory defects in 2018-2020 model year vehicles was insufficiently tightened fasteners on the water pump inlet tube. This defect led to coolant leaks at the connection point.

Some owners experienced coolant leaks immediately after leaving the dealership, so abundant that it leaked out almost completely. Others experienced gradual leaks appearing after 10-30 thousand kilometers of driving.

The manufacturer quickly identified the problem and sent dealers a service bulletin requiring them to check the tightening torque (should be 11 N·m) before vehicle sale, and also to recall all already sold vehicles for service.

A similar problem affected the water pump itself - manufacturing defects led to seal integrity loss.

Start-Stop System and Auxiliary Battery

Manufacturers often installed poor-quality auxiliary batteries responsible for start-stop system operation. This battery is located under the main battery and, according to owner reviews, rarely serves more than two years. The process of its gradual failure is often accompanied by start-stop system malfunctions.

Turbocharging Problems

Pronounced turbo lag during sharp acceleration became a serious problem for many owners. Many note that turbo lag in the Hurricane GME-T4 is significantly more pronounced than in other turbocharged engines.

Boost pressure fluctuations are directly related to turbine operation. During acceleration, engine RPM can rapidly and erratically increase or decrease. In most cases, this occurs due to a faulty turbocharger, less commonly due to:

• Air filter contamination
• Vacuum line seal integrity violations
• Oxygen sensor malfunctions

A characteristic problem of all turbocharged engines became wastegate malfunctions, expressed through increased noise and P0243 error code appearance.

Oil Problems

Besides coolant loss, the fourth Wrangler suffers from increased oil consumption. The main cause lies in a faulty oil heat exchanger - oil begins leaking when temperature conditions are violated.

Another possible oil leak location is a worn or damaged engine oil pan gasket.

EcoDiesel 3.0 V6 Diesel Engine

The six-cylinder V-shaped EcoDiesel diesel engine with 3.0-liter displacement is manufactured by VM Motori. Despite the Italian manufacturer achieving significant progress in quality improvement in recent years, the three-liter EcoDiesel still has design shortcomings.

Main EcoDiesel Problems

The most common malfunction is also related to oil heat exchanger leaks. This usually occurs during heavy trailer towing or after serious loads, such as prolonged wheel spinning, when oil heats to high temperatures and can seep into the engine cooling system, mixing with coolant.

An obvious sign of this malfunction is the appearance of an oil film in the cooling system expansion tank.

EGR System Problems

Another serious problem is susceptibility to EGR (exhaust gas recirculation) cooling system cracking. In October 2019, due to this defect, Fiat Chrysler recalled over 100,000 Ram pickups with similar motors, stating that cracks in the EGR cooler could lead to coolant leaks into the engine compartment.

Although the probability of fire due to EGR heat exchanger cracks is small, a faulty heat exchanger has very negative effects on engine performance. It can lead to uncooled hot exhaust gases returning to the engine, causing overheating.

Fuel System Problems

EcoDiesel vehicles also fell under recall campaigns related to defective high-pressure fuel pumps. This campaign affected vehicles produced in 2019-2021.

Pentastar 3.6 V6 Gasoline Engine

Rocker Problems

The most critical problem of the 3.6-liter gasoline V6 engine is related to rockers (valve rocker arms). Signs of this problem include:

• Ticking sound in the upper engine area
• Misfiring occurrence
• Corresponding errors in electronic control unit memory

Although the manufacturer issued a service bulletin in 2014 aimed at eliminating the defect, rockers on some new Pentastar 3.6 engines still create problems.

Cooling System Problems

Some owners complain about:

• Radiator clogging
• Frequent oil heat exchanger replacement
• Thermostat failures
• Water pump problems

The roots of these problems, according to specialists, lie in production cycle flaws. Main Pentastar engine elements are manufactured using sand casting methods. After part manufacturing, sand deposits remain on their surfaces, which should be thoroughly removed.

Apparently, the cleaning process occurs inadequately, and sand particles remain in parts before engine assembly. Later, during vehicle operation, they penetrate the cooling system and form sediment throughout the system circuit, leading to the aforementioned component failures.

Transmission

Eight-Speed ZF 8HP Automatic

There's no reason to question the reliability of the eight-speed ZF transmission. It's used in numerous vehicles and has repeatedly confirmed its high durability, allowing trouble-free operation up to 200-300 thousand kilometers.

The main condition for longevity is not subjecting the unit to excessive loads, which is quite difficult with a vehicle like the Wrangler, considering the operating characteristics of this off-roader.

Oil in this transmission should be changed more frequently than in regular crossovers - approximately every 30-35 thousand kilometers. This will extend the life of automatic transmission components: friction plates, valve body valves, and solenoids.

All-Wheel Drive System

CV Joint Boot Problems

The main complaint regarding the all-wheel drive system addresses insufficiently durable CV joint boots - they tear for practically any reason. Even exclusively asphalt operation of the Wrangler doesn't help.

The problem is compounded by the fact that the boot separately, as a part, doesn't exist in the manufacturer's understanding - it's only supplied as an assembly with the half-shaft.

Half-Shaft Reliability

The half-shafts themselves also lack durability reserves - both front and rear, regardless of Jeep modification. Among Wrangler owners, there's even a joke that half-shafts are the most expensive consumable for the off-roader.

By 70-80 thousand kilometers of mileage, they typically must be replaced, sometimes even twice, even if you don't engage in serious off-road driving.

Suspension

Contradictory Reliability Assessments

Reliability assessments of the fourth Wrangler's suspension vary greatly. Some drive up to 60-80 thousand kilometers without changing anything, while others experience shock absorber leaks after just 5 thousand kilometers, becoming completely unusable by 15 thousand kilometers.

One owner's case is noteworthy, where a similar situation occurred twice: after low mileage, he had to replace shock absorbers under warranty, but then, after driving approximately the same distance, the shock absorbers again required replacement.

Due to this, many owners replace the stock shock absorber set with branded alternatives after initial problems, since they last longer and work more effectively.

Brake Pad Problems

Brake pads also present certain issues: some owners' pads serve reliably up to 45 thousand kilometers, while others experience uneven wear, with inner pads wearing almost to zero by 20 thousand kilometers.

Body and Interior

Door Bolt Corrosion

Regarding the body, the main problem is rapid door bolt rusting. By 20 thousand kilometers of mileage, they begin corroding abundantly. Prevention can include regular cleaning and subsequent painting - this usually lasts one to two years of vehicle operation.

Rear Window Heating Problems

The main interior problem is **detaching rear window heating contacts**. Enthusiasts long tried to understand the causes of this defect, but finding another definition besides "factory defect" is quite difficult.

Dealers readily acknowledged such cases as warranty issues. Initially, they replaced the entire rear window, but later a special repair kit was developed, which according to reviews is quite reliable - after its installation, contacts no longer detach.

Conclusion

The fourth generation Jeep Wrangler represents a contradictory vehicle woven from modern technologies and traditional assembly quality problems. Such an off-roader requires particularly careful attention, immediately preparing for correction of quite annoying defects for a relatively fresh vehicle.

Purchasing a used Jeep Wrangler JL should be dictated exclusively by emotions and understanding of this vehicle's characteristics, not rational operational considerations. Operating such an off-roader will likely entail certain expenses for eliminating characteristic problems.

Nevertheless, with proper maintenance approach and timely elimination of known problems, the Wrangler JL can serve quite long, delighting owners with its off-road capabilities and unique character.

The key when purchasing is thoroughly checking all known problem areas and being prepared for regular technical maintenance. Only in this case can the legendary American off-roader fully reveal its potential.

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