yes, they need to be removed and tested to verify. if they check out i suppose that leaves the valve seals. but i would not expect valve seals to cause any misfiring... just smoke.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thanks, t walgamuth.

It's interesting to learn that leaking injectors might cause misfiring since it's been impressed upon me that diesels can run rich (as they do at full throtle).

My guess is that a serious cuase would be compression or some other cylinder/piston damage that changes the chamber dynamics. How would those kinds of failures match with the symptoms of smoke, misfire at idle, and apparent normal running at highway speeds and loads?

I'm giving another mechanic a chance to look at it tomorrow.

Thanks,

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-Mike
'87 300TD 304kmi (RIP)
'95 Toyota Camry Wagon 125kmi

If you have an injector or more squirting instead of spraying you would have a lot of unburned fuel and rough running....have them pop tested adn also checked for spray pattern....before you get overly upset about something internal....you can have bad oil rings and still have high compression....

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Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Folks,

It looks like the end of the line for this 300TD. We corrected the hard starting with IP seals and replacing two leaky injectors. The smoke is something internal in two cylinders. I've decided not to consider the suggested repair of replacing the engine.

Anyone in the NYC metro area interested in a parts car? I could risk a ticket (lots of smoke!) for 50mi drive.

This diesel wagon has been a terrific vehicle and, after some serious research, it appears there is no car to replace it in the US for any price except another '87.

Thanks to everyone on the list for advice and entertainment.

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-Mike
'87 300TD 304kmi (RIP)
'95 Toyota Camry Wagon 125kmi