Most Common 3.6 Jeep Engine Problems!

If you’ve bought a Chrysler, Dodge, or Jeep vehicle made since 2011, there’s a decent chance that you went home with a Chrysler 3.6L Pentastar engine. The engine has seen use across a number of vehicle models, giving the machinery thorough real-world testing that helps identify the most common issues to expect.

Most Common 3.6 Jeep Engine Problems!

The Chrysler 3.6L Pentastar Engine

Fiat Chrysler Automobiles (FCA) debuted the Pentastar in 2011. The six-cylinder engine has dual overhead cams and a multivalve system with four valves per cylinder and variable valve timing (VVT). Its use quickly expanded into other vehicle models and has continued to this day.

Dodge included the engine in the Challenger, Charger, Durango, Grand Caravan, and Journey, as well as the closely related RAM line of pickups and vans. Chrysler put the Pentastar into the Town and Country, 200, 300, Pacifica, and Voyager. Jeep’s list is shorter, including just the Grand Cherokee, Wrangler, and Gladiator.

Performance varies slightly depending on the flavor of Pentastar. For example, the Pentastar on the 2022 Jeep Wrangler provides 285 HP and 260 lb-ft of torque. Chrysler overhauled the engine in 2016, improving several components of the engine. These changes lowered the weight of the block while providing similar performance numbers at 295 hp and 260 lb-ft of torque.

Common Jeep 3.6 Engine Problems

Below are some of the most common 3.6 Jeep engine problems. Note that problems from other systems are excluded, such as the V62 fuel pump relay recall that only affected Dodge Durangos and Jeep Grand Cherokees from the years 2011 to 2013. Be sure to check any vehicle you look at for all potential issues before committing to a purchase.

Overheating

Running too hot is not good for any vehicle, and the Pentastar is known to keep a spicy temperature even when operating as intended. The engine thermostat and other temperature warning lights are the first stop in diagnosing an overheating problem, but they can sometimes fail. Extreme symptoms of overheating include steam coming from the engine and total engine failure. The metal around the engine may become exceptionally hot, and you’ll probably notice a difference in smell.

Overheating might be caused by a number of issues, but some of the most likely culprits are problems with the radiator, fluid leaks, or water pumps. Pulling out the radiator and giving it a proper cleaning and fresh supply of coolant can often help with heating issues, but it’s not a guarantee.

If the problem seems to be getting worse, have it looked at by a mechanic before the high temperature causes a cascade of engine issues.

Rocker Arm Wear and Tear

The rocker arms are part of the engine’s valve assembly, assisting with the opening and closing of the intake and exhaust valves. There are 12 rocker arms in the Pentastar, and they’re a source of one of the main Jeep 3.6 VVT engine problems.

When a rocker arm starts to fail, the first indications can be subtle. The fuel economy might suffer and acceleration might lag. As the rocker arm degrades further, you will likely hear a repetitive ticking sound as the part moves. The early failure of rocker arms in the 3.6L was noted by the manufacturer, and later versions received replacement parts.

Replacement rocker arms are relatively inexpensive. A single replacement is about the cost of a fast food combo, and a full set should run around $100. Reaching the rocker arms requires a decent knowledge of the engine and specialized tools for the best results, and it can easily take a couple of hours. Don’t be surprised if the repair bill is several hundred dollars, but it’s still worth the professional touch given the labor involved.

Cylinder Head Damage

Cylinder heads sit on top of the engine’s pistons, forming the main combustion chamber. If the cylinder heads become cracked or otherwise damaged, the engine can leak fluids, misfire, drop performance, overheat, and start smoking. 

For the 2011 to 2013 production years, the Pentastar’s left cylinder head had defects, resulting in an extension of the warranty specifically for that cylinder head in those model years..Getting at the cylinder heads requires only slightly less work than the rocker arms, and a cylinder head replacement will cost much more for the part itself.

The extension of the warranty to 10 years or 150,000 miles for the affected years has begun expiring for the earliest sales, so don’t wait or you may pay full price. The initial rush to replace cylinder heads has long since passed, so getting the part shouldn’t take too long.

General Issues

In January of 2022, plaintiffs filed a class action lawsuit against FCA concerning issues related to a number of vehicles using the Pentastar engine from 2014 to 2020. The lawsuit alleges that Chrysler knew about ongoing problems with the valve train, including the rocker arms mentioned earlier.

The Engine suffers from defects in design, manufacturing, and/or workmanship in components of its valve train, specifically the rocker arms, lifters and related components, as well as in the Engine Control Module (ECM) software controlling the timing and function of the lifters, which cause those components to prematurely fail so that they do not adequately and timely transfer the motion of the cam lobes to open and close the valves (the “Defect”).

Page 2; Maugain et al. v. FCA US LLC

While the lawsuit has not yet been settled, the lawsuit also alleges that any fixes – such as replacing the rocker arms – are only a temporary solution that doesn’t solve the underlying issue. The courts aren’t fast, but keep an eye out for further updates on this case.

Is the Chrysler 3.6L Pentastar a Good Engine?

The 3.6L Pentastar has had a fair number of complaints over the years, but it’s also been in millions of vehicles. It’s definitely not a perfect engine, and the question of whether or not FCA hid the full extent of known problems is worrisome. Intentionally seeking out a Pentastar would be going too far, but plenty of vehicles with the engine are serviceable daily drivers and workhorses.