300 CE-24 Engine problem

I replaced the (blown) head gasket and now the engine runs OK but smokes like a Russian Army tank. It was running perfectly before the gasket blew when I attempted to start
it. I would suspect a broken ring except the compression in the cylinder with the blowout measures 170 psi (the same as the others). The plug in this cylinder is oiling up. Is it likely that the compression ring is OK but the oil ring was broken when the gasket failed? Any other theories? I hate to dig into the engine without some sort of definitive diagnosis. Assuming it is necessary to pull the piston from the #5 cylinder, can I get at the conrod without pulling the engine? Any helpful ideas would be appreciated.
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I would say it is more of valve seal problem than anything else.
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If some oil-leftovers was in the piston-champers this will have to burn away first after 10 minutes drive.

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Here's a theory. The head gasket failed due to a hydraulic lock from oil dripping into the cylinder through the intake's valve seal while the engine was shut down.
Strongly suggest you first look at the valve seals, especially those of the cylinder whose spark plug is fouled. Also check the oil drains from the valve box back to the crankcase oil may be pooling up there worsening the problem.
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A second thought. It could be that a valve guide has comes loose and oil is seeping past it rather than the valve guide seal having failed. This would explain the sudden onset of the problem, the excessive amount of oil in the cylinder to cause a hydraulic lock and break the head gasket and the heavy oil smoke that you now encounter.
And it could be either an intake or an exhaust valve, more likely an intake, but certainly associated only with the cylinder that has the oil fouled spark plug.
I don't know the specific fix for a loose valve guide but there certainly is one for it's not an unknown problem. Perhaps replacement valve guides are sold in "over" dimensions to ensure a snug fit in the now somewhat damaged cylinder head. Ask if that's so.
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Thanks T.G. and others who have responded to my plea. A slip-sliding valve guide could certainly explain the problem. I'm wondering if a cracked head could result in the same sequence of events?? I'm reasonably sure it's more than a seal because the amount of smoke put out completely obscured the country rode I tested it on. I plan to pull the head off tomorrow and look everthing over carefully. I'll post the results of my inspection in the fond hope that others will benefit from my travails. Meanwhile I'm still open for suggestions.

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You may be able to diagnose the problem without removing the cylinder head. I'd first look at it as much as I could before proceeding to remove the head - unless of course you like doing that!
A cracked cylinder head is less likely because you don't mention a coolant leak, contaminated oil or overheating, typical of cracked cylinder heads.
Curious to see what you find.
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The problem is finally solved although I'm not sure how! I replaced the aftermarket head gasket with an OEM version and made sure there was no oil or water in the (blind) deadbolt tapped holes in the block which I had neglected to do before. Otherwise, it went back together just as before. I can't help wondering if all the "smoke" was really just steam from water that had gotten into the exhaust system. When I first ran the engine after changing to the OEM head gasket there was a lot of what was clearly steam coming out of the exhaust. After about an hour of driving it was gone for good. As an aside, I examined three different head gaskets, two OEM and one aftermarket. No two were identical! As it turned out, the OEM gaskets were made by the same company that made the aftermarket gasket.

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My guess is that you have had some oil-leftovers in your engine/cylinder-block and this is now burned away.
Maybe when you refilled your engine with oil you filled too much in it and this oil is now burned away.
Om my holliday to Spain this year with my 190 D 2.5 with a caravan after I accidntly filled two liter too much oil in the engine and I had to stop! I got to a mechanich and he took out the oil and I drove away happily. There was still some leftovers and this took about 10 minutes to burn away - what a lot of smoke.
Niels
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Well, given the other possibilities, that's sure a happy outcome!
Although finding three possible head gaskets sure keeps one on his toes!
Glad to learn the outcome.
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