If you’ve owned any Chrysler/FCA/Stellantis vehicle over the last 10 years, it may have been powered by the Pentastar 3.6-liter naturally-aspirated V6. It is currently available in the Ram 1500 line, among others. It is strong enough to have lasted this long in truck applications, which is a testament to the engine. But the Pentastar V6 has known common problems.
First off, all engines experience some issues, especially those with more miles on them. No manufacturer is perfect. That said, in most cases, your Pentastar V6 will give you many years of trouble-free service.
While we’ll focus on the Ram applications, here are the models the engine is still available in. They are the 2011 to 2022 Chrysler 300, 2016 to 2022 Pacifica minivan, 2020 to 2022 Voyager, Dodge Challenger, Charger, Durango, Jeep Grand Cherokee, 2012 to 2022 Ram 1500 and 1500 Classic, and 2013 to 2022 Ram ProMaster.
Early Ram Pentastar V6 valve seat issue
Left bank cylinder head failures occurred in 2011 to 2013 Pentastar V6 engines. Valve seats became overheated, causing issues. In mid-2013, FCA used hardened valve guides and valve seats which took care of the problem. And it extended the Pentastar’s warranty to 10 years or 150,000 miles for cylinder heads.
For some reason, from 2012 to 2018 Jeep Wranglers were more susceptible to this problem. But other models also experienced some problems. So if you have one of these vehicles, or bought one used, the warranty should in all likelihood still be active.
Should this happen to you, you’ll see the check engine light come on, and the engine might develop a ticking noise. If it isn’t addressed, then the engine could begin misfiring, and there will be power loss. Should the vehicle be out of warranty, replacing the heads can be costly.
Ram Pentastar V6 rocker arm problems
What might seem similar to the valve seat problems above are rocker arm issues. But they are not related. The rocker arms control the valves, so they are one step ahead of them in the process. FCA issued a service repair bulletin for them in 2014.
The issue was the roller needle bearings gave up, which affects the arm’s actions. It usually occurred with engines over 15,000 miles, according to Tuning Pro. While the warranty covered the costs, there was no extension like there was with the valve issue.
So if this happens to you after the warranty period is over, know that this is also an expensive fix. But it shouldn’t be because after the valve covers are removed, the rocker arms are right there. And replacing them is fairly easy. But some dealers replace the entire head assembly, which greatly increases costs.
Symptoms are a ticking sound like the valves are out of adjustment, which they are if a rocker arm has failed. And fault codes or DTCs will indicate misfiring and timing issues. Replacement can run over $1,000. And it may be the best time to just replace all of them, at least on the bank with the issue.
Cooling system problems
The Pentastar V6 also has experienced some cooling system issues. It usually manifests itself as engine overheating, heating or air conditioning issues, coolant leaks, or the check engine light comes on. The issue is the water pump or radiator becomes restricted.
Depending on the problem, you may have to replace the water pump or radiator. The good news is that unlike Chrysler’s previous V6, which required removal of the entire front of the engine to access, the water pump is in front like most cars should have.
As for the radiator, they’re fairly inexpensive, as are water pumps, and easily accessible. Or, you can have the problem diagnosed by a repairman, and replaced for under $1,000.