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Discussion Starter · #1 ·
I have a 78 suburban conversion with a Perkins 6.354. It's a great truck that i bought recently and am working on getting it to a fine running level. I have been running it for over a month as my daily driver and have been noticing more blow-by while it idles. It seems to smoke more and am concerned that something needs done about it.Any knowledge would be great!
 

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Well, I'm finding that there could be some fuel getting into the oil switching pumps and going to see if it helps.having a great time working on my truck..its goin' to be good.
 

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If you are getting fuel into you oil you don't need to change out your pump. Just take yours off and there will be a seal on the bottom where the shaft comes out. There are actully two stacked on top of each other. Easy to replace and cheap.
 

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If you are getting fuel into you oil you don't need to change out your pump. Just take yours off and there will be a seal on the bottom where the shaft comes out. There are actully two stacked on top of each other. Easy to replace and cheap.
OR a much more common fault (with fuel in the crankcase) is the Diaphram in the Lift Pump (lifts fuel from the tank to the injection pump) can have a Diaphram crack and seeps fuel into the crankcase.
But you didn't state that was an issue?
Low rpm Blow by is usually rings though. Ether damaged piston and/or #1 & #2 ring stuck in their groove or even broken. Sounds like a big job but re-ringing one isn't THAT hard to do. New .005" over (or even .010") service rings, after a ridge removal and a hard hone (in the chassis), can breathe new life.
NOTE TO EVERYBODY: ETHER? If you don't know how or when to spray it? DON'T! I remember Detroit and then Cummins powered equipment used a small (half the size of an egg) capsule that fit under a 1" trap door on the intake tube BEFORE the airfilter that worked great in getting just the right amount IN THERE, that saved a LOT of burned/melted Pistons and blown Head Gaskets.
Want to hear a Diesel Rebuilder's Nightmare? Guy runs an articulated Clark Loader with 6.354 Perkins out of fuel.
DRIVES IT ABOUT 100 YARDS TO THE FUEL ISLAND ON 2 CANS OF ETHER. FUELS THE LOADER UP (GRABBED THE WRONG HOSE) WITH UNLEADED GAS. STARTS IT BACK UP ON ETHER AND FLOORS IT SO IT WILL SELF BLEED (HE SAID?) THE FUEL SYSTEM.
YOU SHOULD OF BEEN THERE WHEN THE GASOLINE HIT THE CYLINDERS. The block was TRASHED. The remaining PARTS of the cylinder head were unsavable too.
Terry
 
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