A quick C&P from a Pentastar site:
In June 2012, dealers reported that some engines had premature cylinder head failures, usually on cylinder 2. The problem seems rare considering the number of these engines produced, and nobody was stranded by the problem, which made itself known through the “check engine” light. Customers were generally given loaner cars while the issue was being resolved, though in some cases there was a considerable delay as Chrysler engineers sought root causes (which include “bad gas”) and an effective cure. A fix (hardened valve guides and seats) was engineered and entered production in June, and by mid-July, the backlog of replacement heads was being addressed, and all new heads were of the new design.
Most vehicles with this problem appear to be Jeep Wranglers, and a service bulletin was issued for Wranglers built before January 24, 2012 (MDH 0124XX) seems to be designed to prevent “false positive” check-engine lights.
Any model year 2013 and newer car or Jeep or truck should have the new heads. A “Julian” build date of 2062 (the 206th day of 2012) stamped on the cylinder head shows that it is one of the newer types. The part numbers of the new heads are RL141353AC or higher (left side) and RL141352AD (right side).
) Oil pressure dealio freaked out as I was getting on the freeway today. Shut the car down to 45 mph....not exactly comfortable when you're in the middle of a merge at 7 am.... Waiting to hear when I'll have a Jeep again.
