Hi Guys, hopefully this link works -

https://www.dieseltruckresource.com/...ght=oil+cooler

In this thread in the third picture down you see a small passageway for coolant on the bottom right of the opening in the block. Just wondering if anyone was aware of where this may go? Mine was plugged almost solid with deposits of some sort so I am just interested in where the coolant was supposed to be going.

When I first saw it I thought it was a hole to the bottom end that had been patched up at some time - imagine my relief when I saw the same hole in woodrats picture!

Max

 

I'm not sure where that hole goes. It is really close to where the water pump fits into the block, it might be related to that. I will pull out the cummins book and see what I can find out. My truck came with a coolant filter that the PO had installed, just a sping on type like and oil filter. My coolant has always been clean (other than the oil cooler mess of course!).

 

You talking about the 1/2npt pipe plug in the pic?

 

can't find a specific diagram that includes that hole, but here's the general flow of things according to Cummins:

Coolant is drawn from the radiator by the water pump and the output from the water pump empties into the oil cooler cavity of the cylinder block. I can't remember if that little hole was big enough to be doing that task, but that's what the book says.

I'm assuming that you are talking about this hole:

 

The waterpump outlet is above that small hole on the side and is about 1" in diameter. I guess that small hole can't be of too much importance because I haven't noticed any other problems from it being plugged. Plus the fact it is so small there would never be much flow through it.

 

It's probably there to help vent air during filling or something like that . .