From what I'm seeing in the Cummins manual, that hole is suppose to be there as it is in fact the waterpump's outlet and it plays into the cylinder jacket by design.


Give me a few minutes to post pics.

 

See item no.3 in Flow Diagram A . . . . .




Views A and B
1. Coolant Inlet
2. Pump Impeller
3. Coolant Flow Past Lubricating Oil Cooler
4. Coolant Flow Past Cylinders
5. Coolant Flow To Cylinder Head







Views C and D
1. Coolant Flow From Cylinder Head
2. Coolant Flow to Thermostat Housing
3. Coolant Flow past injector
4. Thermostat
5. Coolant Bypass Passage
6. Coolant Flow to Water Pump Inlet
7. Coolant Bypass Closed
8. Coolant Flow Back to Radiator

 

My bad. I even have access to those same diagrams.

 

so should i just get an air die grinder and clean it up?

 

I'm keeping my mouth shut from here on this one.

 

Only if you want to.




> I won't tell if you don't <

 

hehehehehe

 

What would be the best thing to do? Will I hurt the cooling system if i clean it up a bit?

 

if it aint broke DONT FIX IT!

 

Leave it. Keeps the engine from overheating before the T stat opens. Normal bypass. All 4/6BT's have them.

 

Ok, i will leave it like it is. Thanks for the replys.

 

Took long enough huh )

 

Sorry I didn't see this sooner.

 

Smoothing out the rough edges won't hurt. That is were cracks usually start.

 

Ill be ripping my motor apart in the next week. Ill check mine out and take pics