Example of some fine Cummins work quality

this is correct. And yes use a torque wrench to do it. Don’t try and guess or you’ll be loose or break them. You are supposed to use all new head bolts but they are 40$ a piece or something outrageous. Look at each of your old ones and if they don’t look stretched you can reuse them. But that gives you another reason to retorque

 

The head was not torqued properly, which is common, or a liner dropped. Cummins is all over the map on their liner heights lately. I know of two motors, crate motors direct from Cummins that have had this issue. Sad.

 

Just turning over 800,000 on this ISX. No issues, and sure do love the jakes on these motors.

 

About how far mine made it, then the head went. But, it is a good motor once the emission issue is taken care of. The rest of the truck, that is another story.

 

That's the beauty of being a company hand again.
If the head goes, it's on them.
As far as the truck goes, don't really have a choice in the matter

 

So did you run engine up to temp, up to temp 3 times / cool, or actually drive it?

 

No, because the cm871 isx is a dual over head cam; so if I remember right, the cams have to be out to reach the head bolts. So it’s basically impractical to assemble the cams, injectors and etc, then disassemble just to reach the head bolts again.

That’s why the journeyman I took my ISX to for rebuild, established his own method of waiting overnight. That gives the head bolts enough time to back off. We also marked each headbolt with a marker, a straight line on the head, to monitor and perform the quarter turn or half that Cummins recommends, this is before letting sit over night. The procedure is torque down to a lower ft lbs, then torque to the next rating up, then to the 3rd a final resting torque rating then a quarter turn or what not.

This is how most dealerships do it, then they get right back to putting the cams in and etc.

But waiting over night is something that he does on every rebuild to make sure the bolts didn’t back off a bit

 

My info is based on a N14 red top. I've never done an ISX so I'm sure they are different. I got my info from a Cummins service manual. Just thought I would point that out

 

So you did all 3 step torques, the extra 1/4, let sit overnight, then retorqued?

 

Right, don’t quote me on the 1/4 turn part - I forget exactly what the service manual says either a 1/4 or a 1/2 I think.

But yup, wait over night and torque back to spec