Whats the purpose of this on the m113 motor

[PJmak]

This hole in the valley on top of the engine(under the intake manifold) runs down to the outside of the block. It travels through the area thats covered by the rear main seal. If the rear main seal cover isnt sealed properly, oil will get in the passage and leak out to the side of the block.

Please see pictures.

Hole on top is circled in red. Picture #2 shows the area where the passage ends up on the side of the motor. Pics after that show the area behind the rear main seal and where the passage passes. What is the purpose of this? Obviously, a poorly installed rear main plate will cause oil to come out to the side of the engine. This was the case on my engine.










Circled in red are areas that should have had sealant to prevent oil going into the passage. In my case, it was missed.








This below is the result of that.

 

[gerryvz]

Every MB engine I've taken the intake manifold off of (M117, M119) has a hole in the right rear of the block (driver's side) for oil or fluid to drain out of the V. I'm sure the M113 is no different, though on the M117 and M119 the hole just empties behind the block.

You can see this drain hole pretty clearly in my M117 Top-End Rebuild thread on 126board.com, and my M119 Engine Bay Refresh thread.

M117:

M119:

 

[PJmak]

Thanks for input. I wonder why it goes through that section there where a leak can potentially occur. For me It was leaking so bad I thought it was my oil pan.

I had the engine out and the oil pan off before I found out that the pathway comes through the rear main seal area and was the cause. Could have just gone away with a rear main reseal.

 

[phoenix217]

IIRC this is an oil passage for the crankcase ventilation. It´s not known to leak, but to be blocked. Causing pressure issues. But that was mainly the case on the M112 2.4L.

Might be wrong on this one - but I doubt it’s connected to the hole in the V. Otherwise dirty oil and more could drain back in the engine.

 

[gerryvz]

Every MB engine I've taken the intake manifold off of (M117, M119) has a hole in the right rear of the block (driver's side) for oil or fluid to drain out of the V. I'm sure the M113 is no different, though on the M117 and M119 the hole just empties behind the block.

As much as the @gsxr hates to admit it, there is ONE HELL OF A LOT of similarity between the M117 (old, ancient, yecch!) block and the M119 (new, zoomy, shiny stuff!) block. Most of the differences in these beasts resides above the piston-heads.....

and PS, there is no such thing as an "open deck block" on an M117....