Author Topic: Leaking engine - connection rod  (Read 3455 times)

Petri MRK-25

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Leaking engine - connection rod
« on: June 14, 2017, 20:45:19 »
Hi,

I have 230SL 1964. The engine has been just totally rebuild. However, it leaks oil at the end of the connection rod. The shop is saying that this is due to the fact that the original gasket was made from a material that cannot be used any more and thus, the new gasket is not tight enough.

This sounds odd. Have anyone of you had any similar experiences?

stickandrudderman

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Re: Leaking engine - connection rod
« Reply #1 on: June 14, 2017, 22:10:08 »
What's "odd" is the description you're giving. A connecting rod doesn't cause an oil leak (well, occasionally it does but it's usually preceded by a very loud bang followed by the engine stopping completely but I don't think that's what you're describing).

DaveB

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Re: Leaking engine - connection rod
« Reply #2 on: June 14, 2017, 22:14:54 »
Petri - Of course leaks of any kind on a rebuilt engine are unacceptable.
Is it the rear main seal on the crankshaft?
DaveB
'65 US 230sl 4-speed, DB190

Benz Dr.

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Re: Leaking engine - connection rod
« Reply #3 on: June 15, 2017, 01:17:15 »
Rear main seals can be hard to fit right because it's made of a rope like material. It has to be cut perfectly and even then they can still seep a little bit. A steady drip is another matter and should be corrected.

1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Petri MRK-25

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Re: Leaking engine - connection rod
« Reply #4 on: June 15, 2017, 05:14:55 »
Thank you for comments! And excuse my English - I meant crankshaft, and yes, the back end of it. Good to hear that the fitting of the seal is difficult and that could be the reason for the leak. I will discuss with the shop.

The leak is not minor, I am having a bucket under the engine because of the amount oil leaking. Before the re-build, it did not leak at all.

Benz Dr.

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Re: Leaking engine - connection rod
« Reply #5 on: June 15, 2017, 16:02:06 »
You would have to remove the engine to fix this leak. They probably cut the seal flush with the parting surface of the block and oil pan when it should be cut to about .020'' above the parting surface. I made a small tool for this job and I use a razor knife to cut the seal. You want the cut surface to be as smooth and level as possible. When the oil pan is mounted and screwed down, the small amount of seal sticking out of  the oil pan and block will crush leaving no gap.
 
« Last Edit: June 15, 2017, 18:39:17 by Benz Dr. »
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Petri MRK-25

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Re: Leaking engine - connection rod
« Reply #6 on: June 15, 2017, 18:10:17 »
Benz Dr. - you seem to know what you are talking about!! Greatly appreciated, thank you! This should help resolving the issue.

Benz Dr.

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Re: Leaking engine - connection rod
« Reply #7 on: June 15, 2017, 18:40:21 »
Your English is better than my Finish.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC