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Old April 13th, 2014, 05:13 AM
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Default Re: Blown head gasket vs. cracked block

Quote:
Originally Posted by Vern View Post
I have to top off the oil 2-3 times between fill ups.
Wow, If you are burning through 2-3 quarts of oil between fill ups you would have so much smoke behind you as you drive the you would probably get pulled over. That is a lot of oil to burn so it has to be leaking out, that much oil will make a huge cloud. I don't think this is a head rebuild issue.

If the head is bad as far as losing oil goes it is from bad valve guides/seals that will cause smoky stinky exhaust but even bad guides/seals are not going to dump 2-3 quarts of oil on one tank of gas.
If the rings are bad you will have a lot of blow-by(white smoke) coming out of the valve cover cap/breather when you take it off and a smoky stinky exhaust. but again not going to use 2-3 quarts.

If things were bad enough to use that much oil the engine would not run well or even start. The plugs would be getting fouled up and need cleaning after almost every tank of fuel. It would probably develop misfires regularly.

I think that your front and rear crankshaft seals are the most likely culprits here, they can cause this kind of sever oil loss/leaks DURING driving, they can dump a lot of oil out of the engine onto the road while driving and then show minimal dripping when parked. They only leak severely when they are being bathed in oil while the engine is running. The tell-tale sign for this usually is oil wetness under the truck (especially after driving some distance regularly) behind the engine, and if it is the front seal, then wetness from the bottom front of the engine under the truck.

Dynamic seals like these can get hardened and cracked over time and then they will do little to hold back the oil which is what you are describing now.

If you are otherwise happy with the way the engine runs you may get better results from just buying an engine gasket kit and pulling the motor out to put in all the gaskets especially the front and rear crank seal.

This is not and overly complicated job however it will require loosening and re-torquing the crank shaft. I'm not sure what parts prices are like where you are but I would guess that a complete gasket set would cost you about $50-75 plus your time of course.

If you are leaking this much oil due to old gaskets then you can bet that you are losing coolant from old gaskets too. So it now sounds like that might be you best and cheapest fix, and if you have the tools it can all be done in one day.
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