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What could cause high crankcase pressure? Oil leaks!
I've been having some problems with my truck. A few weeks ago the rear main seal started to leak, eventually getting pretty bad. With the help of a local shop I replaced the rear main seal (observing no damage, other than one jacked up old seal) and it dripped VERY slowly since I did it. I thought it might go away, and if it didn't I could live with the extremely slow leak. Fast forward a couple weeks and the drip is getting worse pretty fast.
Normally I would give up on denial, and admit maybe the crank is worn and it needs to be replaced again with a wear seal, or worse the main bearings are going.
However, my valve cover gaskets have been getting VERY leaky in the last few weeks, to the point where oil is puddling in places, and running onto the exhaust manifold in others. It seems pretty severe, and is uniform across all of the covers.
The crankcase vent tube appears to be functioning normally and I can't find any vacuum leaks.
Is there anything else which could cause high crankcase pressure? I really don't want to have to tear apart the motor, I rely on this truck every day!
Biggest problem causing Crankcase pressure is worn out piston rings. But first, how many miles are on the truck? Havent seen many truck under 500K miles wear out piston rings!
Good way to see if it realy is crank case pressure causing the leaks, let the truck idle, take off the oil cap and see how much blow by is comming out. If you can sit there and see a lot of "Steam" comming out, then you have bigger problems, if its not very visable i.e. you have to squint to see it, not too much to worry about.
You could also replace the valve cover gaskets....they are SUPER cheap and a quick swap!
2008 Ford FX4 F350 6.4 Powerstroke.....I dont really belong here anymore
Forgot to mention that! If I take the oil cap off I really struggle to see any form of blow-by. (Truck has 258K on the clock). That darn mechanical fan makes it hard to tell though, had to use some cardboard and deflect the hurricane force winds, haha.
hurricane force winds i like that. at least you have a sense of humor about it. someone will b able to help you, sorry i can't i just wanted to give kudos for the decent attitude.
1996 2500 clb cab long bed auto, stock airbox with stock filter, no fuel plate, tranny holding fine. Recon L E D taillights an 3rd brake light. isspro gauges, boost, pyro, trans temp, AND MBRP 4inch exhaust, no tip.
Hey I'm having the same exact problem! No visible blow by but the timing cover gasket is leaking and the rear main an some oils coming out of the breather tube but very little. If you figured it out any input would help!! I have 218k on mine. Just did an i/p too
Gentlemen, it is possible that the gaskets are just old & getting dried out. They've gone through alot of heat cycles since these trucks left Ma Mopar alot of years ago. As far as the OP with the new rear main issue, ya, you may be right, the seal surfice on the crank may need a wear sleeve. As far as bearing issues doing it, I doubt it. Hows your oil pressure? Any change lately?
All these 5.9's have some blow by, & I agree with the 500 K before the rings are "starting to wear". I doubt the rings have enough blowby to start blowing gaskets out unless the breather tube is blocked with the mileage you have..
96 4X4 2500,KDP,16.5*,40hp injectors,boost elbow,3K,ground plate to 0,AFC mods,5" exh.BD pressure loc kit,lock up switch,low stall,Rebuilt trans.all billet Boost,Pyro & Trans. gauges,rear air bags,3.54's, 315/70/16's
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