Look. The Pentastar V6 — Chrysler’s replacement for that 2.7L disaster I won’t get into here, plus the old 3.7L and 4.0L — it’s actually a decent engine. I’ll give ‘em that. Smoother than the trucks they used to put in Wranglers. More power. Better fuel economy. By Chrysler engine standards from the 2000s, the Pentastar was a step up.
But the early ones — 2011, 2012, 2013 — had a problem with the left bank cylinder head that Chrysler took two years to acknowledge and three years to actually fix. If you got a Wrangler, Grand Cherokee, Charger, 300, Challenger, Town & Country, or Caravan from those years with the 3.6L Pentastar, you wanna pay attention here.
The deal with the head
So the engine’s got two cylinder heads, right, one each side, V6 layout. The left bank head — bank 2 in factory speak, the side closer to the firewall on most Chryslers — had a casting defect that nobody caught at the foundry. Tiny voids in the metal where the exhaust valve seats sat. As the engine heat-cycled over thousands of miles, those voids cracked through.
What you got was a hairline crack between the valve seat and the water jacket. Coolant gets pulled into the cylinder under vacuum, burns off as steam. Eventually you’re losing a quart of coolant a week with no leak you can see. Then you start misfiring on cylinder 2, 4, or 6 — the left bank cylinders. Then the cat gets washed in coolant and gives up. Then you’re really in it.
What you’ll hear and feel
- Misfire codes on cylinder 2, 4, or 6 (P0302, P0304, P0306)
- Check engine light, sometimes blinking
- Rough idle, especially when warm
- Coolant level dropping with no visible leak
- Sweet smell from the tailpipe
- Reduced power, stalling at idle
- Sometimes white smoke at startup that clears after a minute
The misfire usually shows first. Then the coolant loss. Then the cat. By the time the cat’s involved you’re looking at heads off plus a new converter, which is a real bill.
Chrysler’s response
They issued a service campaign — not a full recall, mind you, but a “customer satisfaction program” — that extended the warranty on the left cylinder head to 10 years or 150,000 miles for affected vehicles. You wanna know if your VIN’s covered, you call your dealer with the VIN, ask about service campaign N49 or W67 depending on which model. Don’t take “we don’t see anything” for an answer. Push back. Make ‘em check the service program flag specifically.
If your VIN qualifies and the head’s failed, the dealer replaces the head — not the whole engine, just the offending head — for free. Includes new gaskets, new bolts, fresh coolant. It’s a real fix, not a band-aid. Takes about 8-10 hours of labor and you don’t pay for any of it.
By 2014 Chrysler had fixed the casting issue at the foundry. 2014-plus Pentastars don’t have this problem. Different story, different engine generation.
What it costs if you’re outta warranty
- Cylinder head replacement at dealer (out of pocket): $2,800-4,200 depending on which model. The Wrangler is at the lower end because the engine bay’s accessible. The minivans are at the higher end because everything’s packed in tight.
- Independent shop: $2,200-3,500. They do the work the same way the dealer does, often a little quicker.
- Used head from a junkyard: Don’t. The casting defect is on every left bank head from this era. You’d just be putting a different broken head on your engine.
- Reman head from a specialist: $800-1,200 for the part, $800-1,200 install. So ballpark $1,600-2,400 total. Legitimate option.
Should you buy one?
A 2011-2013 Wrangler, Grand Cherokee, or any Chrysler with the 3.6L Pentastar is a yes if:
- The left cylinder head’s been replaced under the service program (get the paperwork)
- OR the vehicle’s still under the 10-year/150k extension and hasn’t shown symptoms yet
- The seller’s not playing dumb about it — if they don’t know what you’re talking about, that’s a red flag
If you already own one and it’s running fine: pay attention to the coolant level. Top it off only with the proper Chrysler MS-12106 spec coolant (the orange HOAT stuff). Check it every couple weeks. First sign of misfire on a left bank cylinder, get to a dealer fast and get the head program done while it’s free.
If yours has already failed and you’re outside the warranty extension, it’s still a fixable engine. Pentastar’s otherwise pretty stout. Replace the bad head, drive it another 150,000 miles. Don’t junk the truck over one head.
The 2014-plus Pentastar is honestly fine. The early ones got bit by a manufacturing defect. Chrysler did right by the warranty extension. Pay attention to the timing of when yours was built and what’s been done to it, and these are decent engines.
End of story.