Hi all.. been really getting hard hit this month with stuff breaking. So the cummins decided the water pump was no good anymore. So I replaced it, drove it around all was well. A few days later I went to start it and nothing.. Thinking i left a light on or something like that I recharged both batteries, started her up no issues, shut her down and next morning bam.. nothing again. So after re-charging again and trying to diagnose the issue over a 8 day period my neighbor had a fancy battery tester that prints out the results and it said both batteries were bad after charging for a few days again. So I bought new batteries and she starts right up runs just like before and I am happy. So the next day I decide to drive her to work, she starts up and drives and accelerates like before everything occurred so I am thinking cool. After being on the highway and stopping start traffic I notice the EGT are kinda high, like in the upper 700 degree range which is not usual since prior I would see mid 600's or so max and its now cooler weather. I shift to 5th and the temperature skyrockets over 300 degrees in less than a second to 1100 degrees just hitting the pedal @ 55 mph to get to 70. so I stay in the 60's in the left lane and get to work.. start her up again and head home and its the same thing.

Now when the water pump went out all the coolant came out of the motor and it hit 240 degrees on the gauge till I pulled over to the side of the road.. it was probably like that for less than 60 seconds until I shut her off. Did I do something really bad to the motor at that point or is this a sticking injector or boost leak or something else as it sat for over a week with the battery charging and replacement? I have read quite a few differing possibilities, but I was hoping a diesel mechanic could chime in and maybe point me in a direction.

Thanks! Want to get her back in service soon..

What was the engine temp when the egt went sky high?

Coolant temp? It was 194f Since the failure I have kept an eye on it with my CTS Edge.

Is it possible that you have a bad EGT temp probe or a electrical issue related to your battery problem?

Maybe.. I haven't started to look at it and didn't know where to start haha.

Does it have coolant in it? No big air pockets? I use an Air Sep to fill cooling systems, sucks a vacuum, I let it hold vacuum for 5 or more minutes to check for leaks then let it suck in coolant, no air pockets.

1100 on the EGT gauge? Is the the thermo couple in front of or behind the turbo? If its behind the turbo that means combustion chamber temps probably hit around 1300-1400 witch is piston melting territory, so if the engine still runs and you have good oil pressure and it doesnt look like a smoke stack out the breather I would replace the thermo couple. If its in front of the turbo it could be a legit reading. At any rate what if any other symptoms are there? excessive smoke? what color? Does the engine run smooth? is there a ton of blow by? If the engine seems rough do a cut out test. 2001 should still be an injection pump and nozzles so you can just crack the lines at the injector and see if the engine tone changes more on some holes than others. If you get a difference I would say that injector could be your issue, though I would put that injector in another cylinder and see if the issue follows it. If you have any other questions feel free to PM me.
ETA: if you have a tuner, just ramp it back to stock and see what happens.

I do have a tuner and keep it at level 1. I've talked to other folks and they have lower idle temps than I do and since the EGT probe is at the area that I had the battery charger I think it did it to myself and bent the top of the probe.

It is in the exhaust headers on the left side, right where they meet up, next to the turbo. The engine seems the same to me by sound and no more smoke than prior when getting on the throttle. I have a new EGT probe on the way. Its an inexpensive item to replace before ripping the top off and pulling injectors.

Thanks for the info.

Cool good to hear. It is still a good idea to just start with the probe, they do go bad. But if you continue to see high EGTs do a cut out test and see if anything weird happens. Most people unless they are seasoned diesel guys cannot hear a miss in a diesel. Also when was the last time you did a valve adjustment, out valves can do weird stuff sometimes.

Just as a side note, I run all of my EGT probes after the turbo, and most of the HD engines I work on are set up the same way. Reason being is if a thermo couple breaks the tip can go through the turbo and potentially cause damage. However running it before the turbo takes any guess work out of the temps and gives you a much better idea of combustion chamber temps.

ETA: also another cheap thing to check I forgot to mention would be air and fuel filters, and if I remember right that guys should have a waste gate on it. Make sure it moves freely and the tube on it is in good shape.

Ok have my new EGT probe to swap out.. Will find out tomorrow.  New problem though.. There is a rubber hose tube that sticks out just from under the Passenger side wheel well and frame and drips water, that I thought was just condensation from my AC in there but I have had to refill my radiator 2 times so far and today there was coolant in there.. it gets to 1/4 from the top low.. It dripped a bit after the last drive, then on the next I did not run my AC and it did not drip at all.. Is there a place where Coolant and the AC system meet somehow? Is that the Heater Core? I need to fix this as it seems the coolant system is one thing after another.