Tony:
The new after cooler was installed on my boat today. Unfortunately I do not have many pictures of the unit that failed. The brass end caps off the failed unit showed some minor corrosion and the zincs were in good shape. There was some evidence of a white substance around mating surfaces and the taste test indicated that it was something other than salt.
The O Rings were the black with a green stripe and were in very good shape. I believe these O Rings are the latest version Cummins recommends.
The end caps of the cores were fairly clean as you can see from the pictures. You can also see some minor corrosion and again there was some white residue and based on the taste test it was not salt. We could not get the core to come out even with a block of wood and hammer. I asked for the core to be taken out at the shop and pressure tested and informed the shop I would pay for the work.
After the tech called that one in, the response was that the after cooler, as is, would have to be shipped backed to Cummins for analysis to get the warranty credit. This sounds like one big run around to me and an excuse for me not to see the core.
When we removed the drain valve we could see that corrosion had completely plugged the valve and caused it to fail. There was not salt in the valve only corroded metal.
From what little I could see of the core through the air inlet and outlet, it looked clean and did not appear to have any salt water corrosion. I could see copper, but it was difficult to get a good visual on much of the core through the air inlet our outlet.
Based on other after coolers that I have seen,had I not know the casting had failed, this one looked like it was in good shape and was not in need of immediate service. However, of major concern was that based on the appearance of the end caps and the core itself, I would have expected that the core would have easily come out of the outer aluminum casting. It would not come out. This may have been because of severe corossion or because the casting was cracked and no longer shaped properly, it was impossible to tell.
A little more history on the engine and boat:
Manufacturing of the Engine: August 11, 2015
Completion Date of Boat Manufacturing and shipped to Dealer in Florida: January 2016
Date I purchased the boat New from the Dealer: May 16, 2016 (Hours on the Engine 7.3)
Failure of After Cooler Housing: October 12, 2017 (Hours on the Engine 281)
There are no records of any modification made to the engine or after cooler made by Cummins or an Authorized dealer. In other words the after cooler that failed was on the engine since it was manufactured and no one worked on is since that time. ( I know that since May 16th, 2016 that nothing was done to the after cooler other than replacing zincs every six months.)
Based on what I saw I am completely at a loss of why this failure occurred. I doubt I will ever know.
I am having a oil analysis done to make sure that there the oil does not have a high sodium or iron content. In addition we did a blow by test and everything was fine.
I do not know how I could have prevented this failure and probably will never know.
Mark Gacka
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