Chrysler PowerTech 3.7 V6

The V6 derived from the PowerTech V8 — essentially that engine with two cylinders removed — fitted to the Liberty, Grand Cherokee, Dakota, Nitro and Ram until the Pentastar replaced it.

It shares its parent's sensitivity and its parent's failure modes. Valve-seat wear and dropped valve seats are the fault it is specifically known for, presenting as a misfire and low compression on one cylinder with no obvious external cause, and often after an overheat. Once a seat has moved, the head is generally scrap.

As with the 4.7, sludge from neglected oil changes is behind much of the camshaft and rocker wear that these engines show, and the rocker arms in particular are a known noise source. It is not a fragile engine when maintained, but it punishes neglect more than its contemporaries do — which makes service records the most useful thing a seller can produce.