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3.3 Rocker Arm Pedestal Breakage

The 3.3 valvetrain, early on, had an oiling system problem that contributed to the pedestals for the rocker arm (valvetrain) to break off of the head.

The oiling aspect to this problem was fixed by 1992, however 1990 and 1991 model year 3.3s do run the risk of the pedestals snaping.

It is, by and large a very rare problem- but it does happen.

This picture I saw on eBay one day on a 1991 Dynasty that had the rocker arm pedestal breakage problem.

Surprisingly in years that had the oiling problem, the front bank would be the one to have the breakage occur.

However this problem was not resolved after the oiling system was fixed.

It became aparent that, athough rarer than before with the oiling system fixed, rocker arm pedestals were continueing to break... and oddly only on the rear bank (passenger's side bank on longitudal 3.3s).

My theory on this is that the casting for the heads on the 3.3 is weak, and the rear bank's pedestals are prong to breaking under very specific conditions- such as heavy load, etc. The pedestals are rather small for the type of metal used in the mopar 3.3 heads (aluminum) however that in and of its self is not the problem, as if it would- that would allow the front bank to be equally subjectiable to breakage- which on 1992+ 3.3/3.8's- is not the case.

Also, oiling system problems can be ruled out on newer 3.3s with this breakage occuring- as alot of the engines that have it happen, have nice- wet, sludge-free valvetrains when taken apart for repair.

The newer engines that have the breakage occur also always have the pedestals break at the same spot, surprisingly a different spot than the oiling-related breakages of 1990 and 1991 models.

Thus I strongly believe that this is a casting problem, and/or something going on during the production of the rear bank cylinder heads. Since this is rare, perhaps Chrysler used the cylinder head molds too long before discarding them, who knows.

Thankfully its a really rare problem and when it does happen, there is a fairly easy and cheap fix. All you have to do is machine out the pedestals and make a tap/bore that goes all the way threw the head (to where the head and block surfaces meet) and use a grade8 bolt in place of each pedestal. I talked to a guy who had this done at a shop for only $60 bucks!

This repair could also be done as a preventative modification to the heads if you ever have your heads removed for some reason (be it porting, etc).