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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!




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Replies (5)

Replies (5)

I've had a number of Imperials and Chryslers, and one of them used a lot of oil. It turned out that it had the wrong dipstick, and the crankcase was being consistently overfilled. I would make absolutely sure that there are only 5 qts of oil in the crankcase, drain ad refill to be sure. Check the oil, and mark the dipstick.


That solved the oil consumption problem in my 64 Imperial.


Perform a leak-down test on the engine to determine it's true state of health. I used to responsibly drive (the snot out of!) a 1969 Roadrunner with a 383. If I happened to take it above 5200 RPM, it would emit a huge cloud of oil smoke from the exhaust because the valve seals and guides were pretty much used up. The very efficient Chrysler oil pump simply filled the rocker covers full of oil, and engine vacuum did the rest. I could have made big money killing mosquitoes! Also, the PCV valves on those old RB's can get sticky and admit enough oil into the intake to make you think there is something seriously wrong. Check that as well.

Intermediate Driver

I have had a couple of 440 MoPars and they all burned a lot of oil.  They were all in the 80 to 90 thousand mile range and it was  always valve seals.  You would have sworn that all the oil rings were laying in the oil pan.  MoPar uses umbrella type seals and when they harden with age they don't do a very good job.  When I took the valve springs off my '67 Coronet R/T with a 440 half the seals had actually broken and bits of the were laying in the head.  If the oil rings have gummed up and seized in their groove, but the compression rings are still in good shape a compression test will not say much.  Do the valve seals and if that doesn't clear up or significantly reduce the oil consumption you are looking at rings.  Also do make sure the oil level is correct as suggested else where.

New Driver

Great work Sajeev!

Community Manager

patience and the right tools? there's some crazy talk!

Glad to see you Sajeev, you have landed in a fine place. Hope the Best and Brightest are following you here. (If they did not then they wouldn't be "best and brightest" now would they?)

New Driver