Which Jeep Grand Cherokee Engine Is The Most Reliable?

By Nick Marchenko, PhD

Which engine is the most reliable in a Jeep Grand Cherokee? That’s a question that many Jeep owners ask. There are several different engines available in this make and model, and each has its own set of pros and cons. Let’s take a look at each one and see which one comes out on top.

Which Jeep Grand Cherokeen engine is the most reliable?

Although the current Grand Cherokee has been involved in a few drivetrain-related recalls lately, it surely must have had some extremely powerful engines under its hood throughout its history. This is a genuine dual-purpose on and off-road vehicle, as defined by Jeep - "real SUV" if you will. Engines (and automobiles, for that matter) were simpler back then, so they tended to be more dependable.

Whenever you ask Jeep owners which engine is the most reliable in a Jeep Grand Cherokee, you’re likely to get a variety of different answers. Here are several very popular options available on the market.

Magnum VS HEMI

The Grand Cherokee's first engine was the Magnum V8, which was introduced in 1987. It had a displacement of 5.2 liters and produced 220 horsepower, 30 more than the base engine. It used a lot more gas but generated 20 hp more than the previous iteration of the 318 ci Chrysler V8 (220 hp). In 1998, Jeep debuted a larger, 5.9-liter version of this same engine in a "5.9 Limited" edition as a way to commemorate the original 360-cui GC's retirement after 15 years on sale - itself a continuation of its previous 360-ci V8 (220 hp).

With such characteristics, it was natural for the 5.2 and 5.9 L Magnum engines to be replaced by the even more powerful HEMI V8s in 2004. The new 5.7-liter HEMI engine produced 330 horsepower and 375 lb-ft of torque, making it the most powerful engine ever available in a Jeep Grand Cherokee at that time.

Moreover, this motor is considered to be the most reliable because, unlike the 5.2 and 5.9 L Magnum V8s, which were only used in Jeep Grand Cherokees, the 5.7-liter HEMI engine was also used in a number of other Chrysler vehicles - most notably, the Dodge Charger, Challenger, and 300C.

AMC

The AMC motor with 190 hp, 4.0l inline-6, was used in the Jeep Grand Cherokee from 1992 to 1998. It is considered extremely reliable, as it was also used in a number of other vehicles - including the Wrangler and Cherokee - where it proved to be very durable. The 4.0 AMC engine is often lauded for its simplicity and reliability. It is a popular choice for those looking for an engine swap, as it can easily be swapped into a number of different vehicles.

Chrysler produced four engines after acquiring AMC in 1987, and this engine has been highly rated since. Popular Mechanics included it on their list of "The 10 Best Engines They Stopped Making In The Last 20 Years." The article cites that the engine can regularly last 200,000 miles without any kind of rebuild and survive in "running conditions that would kill most motors."

It's a shame the 4.0 couldn't continue development, but Jeep had to cancel production of it due to increasing emissions regulations. The 4.0 was the entry-level engine in the Grand Cherokee until the third generation launched in 2005, replacing it with the far more problematic 3.7l Powertech V6 as the base option.

So, if you are a driver who wants an engine that will offer great power and torque while still being able to go the distance, the Magnum or HEMI V8s are your best bet.  However, if you are looking for an engine that is more reliable and easier to maintain, the 4.0 AMC inline-6 is the way to go.

Supercharged 6.2L V8 Engine

The Grand Cherokee's top-of-the-line Trackhawk trim offers one incredible V8. The 6.2L V8 was designed to get you from point A to B as swiftly as possible. Enjoy the rush of unadulterated speed as it unleashes 707 horsepower and 645 pound-feet of torque.

This is the most reliable Jeep Grand Cherokee engine created nowadays, because, as said before, it's used in other Chrysler products, which means that the company has had to perfect it. Supercharged has features like an improved cooling system, forged internals, and a high-strength steel crank to prevent flexing.

You can buy this engine if you're looking for speed and power. It is however the most expensive engine on this list. That is due to the fact that it has a lot of features that make it unique. For example, the forged internals and the high-strength steel crank. Overall, this Jeep Grand Cherokee engine is the best one you can buy if money is not an issue.

Will it drive only with diesel?

The previous generation Grand Cherokee (2005-2010) had a diesel engine option that was sourced from Mercedes. It was more reliable than the newer engine used in 2014, but it's known to develop leaks at the oil cooler and carbon buildup on fuel injectors due to seal failures. Those motors that were used in Europe were actually more reliable, but the US models had a different design that was less robust.

The new Grand Cherokee, much like its predecessor, is available with a 3.6-liter V6 or 5.7-liter Hemi V8 engine. Jeep also offers a plug-in hybrid 4xe powertrain option for those interested in electrification without sacrificing SUV capabilities. Besides, a diesel engine is optional on some models. So, which engine is the most reliable?

The answer may surprise you. The most reliable engine option in the Jeep Grand Cherokee is actually the 3.6-liter V6. This engine has been used in a variety of Chrysler vehicles and it’s generally considered to be a reliable powerplant. It’s also worth noting that the 3.6-liter V6 is the only engine option that’s available with a factory warranty of 5 years/100,000 miles.

Thus, diesel motors that were previously used on older models, nowadays, are not as good as they used to be. The most reliable engine among all available options in the Jeep Grand Cherokee is the 3.6-liter V6. It has a long warranty period and doesn’t require much maintenance.

Final words

Well, when you already know the most reliable Jeep Grand Cherokee engine, it's time to make a decision. Are you looking for power and speed or reliability and a long warranty period? Choose wisely!

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

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