Chrysler 3.6L V6 Pentastar Engine Specs, Problems & Reliability

Chrysler 3.6 Pentastar Info

The 3.6L V6 Pentastar is a 3.6-liter six-cylinder gasoline engine introduced first at the New York Auto Show in 2009 for the 2011 model-year Chrysler, Dodge, and Jeep vehicles. This new V6 is one of the most technologically advanced engines to date, created by Chrysler. This V6 is used in popular vehicles around the world such as the Dodge Challenger, Jeep Cherokee, Jeep Wrangler, and Ram 1500. The 3.6L Pentastar V6 for three years in a row was among the top ten engines in the US market. Let's take an in-depth look at the 3.6 Pentastar engine design, its common problems, reliability, and longevity.

3.6L Pentastar Engine Overview

The new 3.6 V6 engine is 38% more powerful, consumes 11% less fuel, and 42 lbs (19 kg) lighter than its 3.5-liter predecessor. It is also smaller in size: 94 mm shorter than the 3.7 and 34 mm than the 3.5 V6. The engine has a high-pressure die-cast aluminum cylinder block with a 60-degree V angle between cylinder banks. It has an open-deck design that saves material, lighter and cheaper to produce, and has cast iron cylinder liners for increasing longevity. The engine block is equipped with three piston oil cooler jets. Each oil jet cools two pistons, preventing detonations by managing heat. There are forged steel connecting rods, the nodular iron crankshaft, and cast aluminum pistons with low-friction rings and reduced skirt area for less weight and friction. The engine uses a chain-driven, vane-type variable displacement oil pump. Engineers removed all brackets for the engine accessories. The alternator, air conditioner compressor, and belt tensioner are bolted to the engine block. They are driven by a serpentine belt as well. This arrangement has significantly reduced the level of vibration and noise.

The 3.6L Pentastar has sand-cast aluminum cylinder heads made of T7 heat-treated aluminum. The cylinder head features 4-valve per cylinder and dual overhead camshafts with roller finger followers with hydraulic lifters. The intake and exhaust camshafts are chain-driven (there is a separate timing chain for each head). Timing chains are a "silent chain link" design. All four camshafts come with torque-actuated phasers. The intake valve has a single-piece design and is made of forged heat-resistant (martensitic) steel; the intake valve diameter is 39 mm. The exhaust valves have a two-piece design, with a forged austenitic head welded to a martensitic stem. The exhaust valve diameter is 30 mm. Cylinder heads feature high-flow intake and exhaust ports and an integrated exhaust manifold. On top of the engine, there is a lightweight composite intake manifold fitted with a 74 mm throttle body and an electronically controlled multipoint port fuel injection system.

90% of maximum torque is achieved in the range of 1800-6350 rpm. Thus, the engine can provide excellent driving dynamics without requiring high-octane (premium gasoline). While Pentastar engines are not demanding on fuel quality and sufficiently simple to maintain, they feature exceptional fuel efficiency, low emissions, and smooth operation. Pentastar V6 engines are popular both in the United States and beyond. They meet Federal Tier 2 BIN 5 emission requirements, Ultra-low Emissions Vehicle II standards, and Euro6 standards. It is also designed to meet stringent future standards, including LEV III and PZEV California standards.

2016+ Pentastar Engines

In 2016, FCA released an upgraded Pentastar engine family and a new version of the 3.6L V6 for the Jeep Grand Cherokee and Dodge Durango. The revised engine now has a two-stage variable valve lift (VVL). The VVL system provides low and high valve lifts. Low-lift settings at low speeds save fuel (up to a 2.7% increase over the previous version), while high valve lift turns on when power is needed. Unfortunately, the manufacturer was forced to install a cooled exhaust gas recirculation (EGR) system. The modified engine also features a new plastic intake manifold with longer runners, increased torque, high-tumble intake ports inside cylinder heads, new valve springs, and low-tension piston rings. The fuel system received new eight-hole injectors. And the good news is, the engine has kept a port fuel injection. The variable valve timing (VVT) system was recalibrated. The compression ratio was increased from 10.2:1 to 11.3:1. These improvements help to produce more power and torque together with better fuel efficiency and emissions.

In recent years, the Pentastar V6 engine successfully competes with the more technologically advanced 2.0L turbo four - 2.0-liter Turbo Hurricane.

Engine Specs

3.6 V6 Pentastar Common Problems and Reliability

Is the 3.6 Pentastar a good, reliable engine? Well, this 3.6-liter V6 has been around for a long time (almost 11 years), and for a good reason. The 3.6 Pentastar has high power for the V6 NA engine and is efficient and reliable. However, owners of these engines may face some common problems. Let's take a look at these issues in this article below.

The Most Comon 3.6L Pentastar Problems

Here is the list of the most common Dodge/Jeep 3.6L V6 Pentastar engine problems:

• Cylinder head failure
• Rocker arms problem
• Cooling and oiling issues

Pentastar 3.6 Cylinder Head Failure

The left side cylinder head problem had been found in about 0.5% percent of 2011-13 vehicles with 3.6-liter V-6 Pentastar engines. Engines with cylinder head failure can be easily recognized by a ticking sound from the left side. Sometimes they had other symptoms, including a check engine light illuminated, misfires, and power loss. The failure was caused by excessive wear. In August 2012, Chrysler made the design upgrade. Revised heads come with hardened valve guides and seats, and the problem is rarely reported now. All 2011, 2012, and some 2013 model year vehicles with 3.6L Pentastar engines have extended engine warranty on the left side cylinder head to 10 years or 150,000 miles.

Problem with Rocker Arms

Very often, this problem is confused with the one described above. The most common symptoms are very similar - a ticking/tapping sound from the upper engine area and a cylinder misfire. You can also find a diagnostic trouble code (DTC) indicating misfire. To address this issue, the FCA issued a service bulletin in March 2014. However, some newer Pentastar 3.6 engines still experience rocker arm failure, and there are no any additional warranty periods for this problem from the FCA.

Cooling System Issues and Oil Pump Failure

Some owners complain of problems with clogged-up radiators and frequent replacement of water pumps, thermostats, oil cooler, and oil pumps. The problem may lie in the production and preparation of an individual engine before assembly. The heads are sand-cast and undergo serious inspections for cleanliness before reaching assembly plants. But any residual sand that remains from the casting process inside the engine can also circulate through the vehicle's cooling systems, causing clogs in the radiator and oil cooling system. Fortunately, this problem is not as common as the ones listed above, but it is very annoying since many stories on the internet from owners who went through these same repairs multiple times.

3.6L V6 Pentastar Reliability Summary

So, is the 3.6L Pentastar engine reliable? Summing up, we can say the Pentastar 3.6 reliability is way above average. It is time-tested well enough, and over 10 million Pentastar engines were produced to date. Despite that they had some issues early on, the 3.6L V6 Pentastar is great, durable, one of the most reliable engines available on the market right now. With proper maintenance, the 3.6 Pentastar engine longevity is around 250-300k miles (there are even a few cases of the Pentastar last up to impressive 500,000 miles).