Piston Slap: Oil Consumption on an Imperial Scale?
Hagerty’s very own Don Sherman writes:
I have a 1965 Chrysler Imperial powered by a 413 cid V-8. It runs well but consumes a quart of oil every 150 miles. I suspect faulty valve stem seals. Do you concur? Can they be replaced WITHOUT yanking the heads or other more involved procedures?
Sajeev answers:
While bad valve stem seals aren’t a common problem on Chrysler’s “wedge” engines, anything can happen on a 45 year old car!
Usually these go bad when blue-white smoke is present upon cold starting, or upon initial acceleration after long periods of idling (when engine vacuum is the highest). If so, then you found the source of your oil consumption. If not, maybe this is a good time to do a compression test to check the health of the piston rings?
But let’s assume the seals are toast: as you stated, the fix isn’t too bad as you only remove the valve covers and need not remove the heads from the motor. You’ll need access to a source of compressed air, and the correct threaded tool to pressurize each cylinder (via spark plug hole) so the valves won’t drop into the combustion chamber. I have seen people stuff a (presumably clean) nylon cord in lieu of compressed air, but I’d be leery of adding nylon debris into the combustion chamber.
After acquiring the appropriate valve spring removal tool, remove the spring/lock/retainer and finally the seal. Installation is the reverse of removal and you get to do it all over again another fifteen times! The work isn’t necessarily difficult, but definitely requires patience and the right tools.
Or not: depending on mileage, perhaps this is a good time to get the heads rebuilt. Or opt for extra performance with a set of aftermarket aluminum heads, but that’s beyond the scope of this discussion.
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