Detroit 671 TI rebuild

Or a bad injector tube or 2.

That's the same thing that happened to my fresh overhauled 12V71TI several years ago. The rocker bridge pin is pressure fit and there is anti-freeze flowing under it. Mine loosened on the new cylinder head and my fresh overhaul was toast at 71 hours.

Ugh...would make me sick. Was this the mechanic's fault; should it be checked out during the rebuild while things are apart for inspection? or is that not the case.
Or did you have to eat it? And take it and like it....?

It seems like pressure testing would be a good idea after overhaul. (pressuring the fresh water cooling system). This is how the problem was discovered after finding coolant in the oil. In my case, the shop refused to take responsibility for the $65k in hull overhaul that failed at 71 hours. The cylinder head was not a Detroit Diesel certified part (because Detroit didn't have any cylinder heads available at the time) so, out of all the parts I purchased for overhaul, this is one of the parts that was not a Detroit Diesel OEM part. Anyway ... just bad luck and disreputable shop. Ultimately, there was even more wrong with that engine though ... eventually replaced the entire block after 2 additional failed overhauls due to the liners not seating properly. I think we are good now.

I also learned to remove the engine or trans to do the overhaul. It's just a far better way to do it.

Mine was a new replacement cylinder head. I forget where it came from. That was 2010.

Bad metal? I'm not sure what caused it ... potentially severe overheating before the initial overhaul. (I purchased the boat with one engine in need of overhaul). Eventually, we were sure that the cylinder liners had been carefully fit and when they came up with one cracked and several with a horrible fit, it was finally time to make a drastic change and get a fresh block.

I have had things fixed things 3 times before putting a problem to rest on more than one occasion.

They make liners for a 12v71 in 4 different sizes. I had one rebuilt where some took a #3, others took a #2, etc. that particular motor came apart at 150 hours after overhaul from a Detroit diesel dealer and they had used all #2 liners and some were loose.

Yes ... we were aware of the different sizes of liners. At the initial overhaul, there was discussion that if the sleeve didn't fit well (out of round), it might make the in hull overhaul difficult or impossible. At each successive overhaul, the technician would complain "who fit these liners"? "Terrible job...".

It wasn't until the same shop overhauled the same engine twice that there was no question that there was a reason that perfectly fit liners turned up loose and cracked. I think the problem is solved now.

Was waiting for you to chime in; That's what I thought.

Sad ,but true. I'm going back to 1992 or so , 8V71 went bad on us at Fernandina Beach on our way up north from Daytona to the Chesapeake .
My Dad got some one local recommended to us by the local marina and yeah he was missing a tooth or two and had grey or little hair etc, he was able to figure out the problem though...water leaked into the top of the cylinder heads... hole in riser . Plus knew what he was doing.

Then in 2001 I got my 6V53 overhauled and the young guy, 30ish, I contracted with brought in this older odd looking gentlemen 65/70 to work along side with him to do the onboard overhaul, which went very well.

Both men were as you say, Capt Ralph.

The guy I use now has 30 years at J&T N.J. under his belt, he's good but needs encouragement from time to time. And he's young! 59...