THINK TWICE

The defining Chrysler Pentastar 3.6 defect is left-bank cylinder-head failure on the early (2011-2013) engines: valve-seat erosion in one head produces a cold-start ticking that progresses to misfires -- P0300 plus cylinder-specific codes, most often cylinders 1, 2, 3 and 5 -- and can let combustion gases into the coolant. 193 federal ENGINE complaints across the 2011-2013 Grand Cherokee, Grand Caravan and Town & Country and the 2012-2013 Wrangler describe ticking, misfires, or a replaced head. Owners report Chrysler extended coverage to 10 years/150,000 miles on the LEFT head only; on 2011-2013 cars that term has now lapsed by calendar.

Check — Cold-start, listen for a top-end tick that fades as the engine warms; scan for stored or pending misfire codes and check for coolant loss with no external leak. Ask whether either cylinder head was replaced, and whether it was the left (warranty) or right (owner-paid) side. The 10yr/150k head extension is expired on 2011-2013 cars, so a future failure is out of pocket.

The defining Dodge/Ram Hemi 5.7 failure is MDS lifter and camshaft wear -- the internal "Hemi tick": the multi-displacement-system (cylinder-deactivation) lifters on the deactivating cylinders wear and collapse and score the camshaft lobes. Owners report a top-end ticking, a cylinder misfire (P0300/P030x codes), rough running or shaking, metal in the oil, and in the worst cases stalling or a seized engine. 292 federal ENGINE complaints across the 2009-2019 Ram 1500, Durango, Grand Cherokee, Charger and 300 name lifters, camshaft, MDS or cylinder deactivation; among the mileage-known reports the failures cluster around 100,000 miles (median). These models are engine-mixed, so this describes the 5.7 Hemi specifically, not the 3.6 V6.

Check — Cold-start and listen for a persistent top-end tick that does NOT fade once warm (this is the catastrophic one -- distinct from the exhaust-manifold-bolt tick in HEMI-2); scan for stored or pending cylinder-misfire codes, and ask whether the camshaft or lifters were ever replaced and whether there is metal in the oil. A proper repair is a camshaft plus a full lifter set (sometimes a short block), so budget for a major engine repair on a high-mileage 5.7.

A second, look-alike Hemi 5.7 "tick" is broken exhaust-manifold bolts, NOT an internal failure: the manifold bolts shear -- often loudest at cold start -- producing a ticking or tapping and an exhaust leak. 269 federal complaints, overwhelmingly on the Ram 1500 trucks (with a handful on the Durango, Grand Cherokee and Charger), describe broken manifold bolts or an exhaust-manifold tick. Owners routinely confuse this with the lifter tick in HEMI-1; it is a far cheaper, non-catastrophic repair, though snapped bolts can be hard to extract and a leak near the firewall can let exhaust fumes into the cabin.

Check — Distinguish it from the lifter tick: a manifold-bolt tick is loudest cold, is tied to an exhaust smell or a "leak"/ticking sound at the head, and throws NO misfire code. Inspect the exhaust manifolds for broken bolts and soot tracks; a durable repair replaces all the manifold bolts (many shops use an upgraded stud kit) rather than just the one that let go.