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Old 10-19-2005, 01:56 PM
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Join Date: Mar 2000
Posts: 534
1991 350 SDL - OM603 Pumping Oil Out Exhaust

1991 350 SDL, 149K miles. Oil has been present in the coolant expansion tank for some time now, but vehicle displayed no loss of coolant or motor oil and ran fine.

Until last week, while traveling at 80 mph, large clouds of smoke started billowing out of the exhaust pipe. Engine now starts readily but runs quite rough; white exhaust smoke is present at startup and idle; engine coolant level is now low. No coolant condensation is present on the underside of the oil filler cap. Engine oil is noted to be dripping out of exhaust pipe while the engine is running.

Given the OM 603's spotty hx, should this engine be totaled and a factory reman installed... or, if there is no damage to the bottom end, would the installation of a new cylinder head be proper and sufficient?

I understand the factory reman incorporates a substantial number of improvements.. but it lists for over $11K.

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Old 10-19-2005, 02:03 PM
126 Guy
Join Date: Sep 2005
Location: Queens, NY
Posts: 523
i would say to put a new head, new gaskets and replace the rods that the 350 engine is known for breaking.
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Old 10-19-2005, 02:03 PM
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Join Date: Jun 2005
Location: NJ
Posts: 1,182
Your sdl has now crossed the line and become a money pit. When do you want me to come by w/ my free car disposal services?

Check compression. Has it been using LOTS of oil?
The picture isn't as bad as you think. A used 3.0 motor with your head (if it is okay) is the way to go if you have rod issues.
I got my 350 sdl because I figured I'd go the 3.0 route if the sky falls on me.
82 300D....went to MB heaven
90 350 SDL....excercising con rods
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Old 10-19-2005, 04:50 PM
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smoke gets in your eyes
Join Date: Jun 2000
Location: SF Bay Area
Posts: 20,794
It might just need a new head gasket. Pull the head and examine the gasket particularly in the area between the timing chain cavity and the #1 cylinder. Then check the roundness of the cylinder bores. If the bores are way out of round then there's a big decision to make. But you have other decisions to make at this point so don't think about rods and rebuilds just yet. Pull the head and start collecting facts.

87 300SDL
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Old 10-19-2005, 11:44 PM
Join Date: May 2002
Location: Blue Point, NY
Posts: 25,396
Follow Sixto's advice.

And, I'm going to have this thread moved to DD. Watch for it over there.
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Old 10-20-2005, 12:09 AM
t walgamuth's Avatar
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 35,281
i agree with sixto and brian

and would add that since it is a 350, while the head is off, get someone to measure the distance from the top of the block to the top of each piston at top dead center to see if it has any bent rods.

i didn t know to do this and so now wonder if the rods on mine are slightly bent. the compression is not off by much but i still wonder.

tom w

[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.
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