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.
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.
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.
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.
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
Curious to see what you find.
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.
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.
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