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Old 11-03-2012, 11:54 AM
franklynb franklynb is offline
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Join Date: Feb 2007
Location: Milwaukee, WI
Posts: 200
Quote:
Originally Posted by 97 SL320 View Post
Blindly ripping things apart before a proper diagnosis is performed is a sure route to more problems / failure.

The proper route would have been to perform a leak down then you would have known for sure if there was a leak from combustion to coolant. This would have also identified the exact cylinder.

The leak area you have high lighted leads to a dowel pin and not coolant. It is possible that slight combustion gasses were making their way to the dowel pin but that isn't the cause of the overheat.
I'm perhaps not as blind as you think.

The transmission had partially failed ;
and the engine had shown exhaust guide wear from a leakdown test and chain measurement done several months ago.

Doing a proper leakdown --with known leaking valve guides-- is a bit of a crap shoot, yes?

And the "threaded boss" is just that; NOT the dowel pin next to it, which is also
rusted. And its the only boss with rust, as previously stated.

In particular, I am concerned by the SPALLED tracks between the cylinder sealing area, the dowel pin perimeter and the boss
... which might/might not show combustion gas mixing with something else, like coolant from the port to the left of the boss --

-- IF I'm not "blind". Sarcasm noted.
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--frankb

1982 300TD 617.912 <NLA> . 1975 2002 E10-EFI . 1976 914c6 . 1983 MG LMIII <NLA>. 1988 Montero / 616<NLA> . 2001 TLS . 2005 Saab 9-5 Wagon
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