In 2008 those that chose the Cummins engine option in their Ram truck, welcomed the 6.7L variant and said goodbye to the outdated 5.9L engine that had been used in the Ram truck since 1989. While the 6.7L seemed to be superior in almost every way as compared to the 5.9L, Cummins was forced to add an EGR system as a result of stricter emissions control mandates. This meant that the same EGR cooler failures that had existed on the Power Stroke and Duramax variants in previous years, were sure to happen on the Cummins engine as well. While Cummins EGR cooler failure may not have been as commonplace for the Cummins engine as it was for the 6.0L Power Stroke engine, there were still failures and many times this would lead to more serious engine damage.
When an Cummins EGR cooler fails, it will normally allow engine coolant to enter the cylinders and cause white steam or smoke out of the exhaust. Many times this would be thought of to be cylinder head/head gasket failure, as this symptom - without an EGR system - normally would be. Because this EGR cooler system was so foreign to the faithful Cummins owners and technicians alike, many times this problem would be misdiagnosed and of course head gasket replacement would not solve the problem. This turned out to be a very costly mistake both for the professional working on the engine and vehicle owners alike. Once word got out that the factory EGR coolers were problematic and that if it failed, it could cause serious engine damage, end users and repair facilities started looking for a suitable upgraded replacement.
The factory Cummins EGR coolers utilize a tube and fin style heat exchanger, the internals look similar to a radiator. The problem with this is as the internals of the Cummins EGR cooler heat and cool, the metal also expands and contracts. Over time this constant expansion and contraction puts serious stress on the internals because they don't have flexibility, ultimately leading to cracking of the heat exchanger. Once this internal failure happens, engine coolant will be allowed to enter the cylinders or exhaust system, causing all sorts or more serious engine damage including cylinder head gasket failure. This type of internal failure is very common amongst all factory EGR coolers and to date it doesn't look like the OEM’s are interested in solving this problem. The word is that the OE’s make more margin or profit from selling unreliable replacement parts, than they do when the truck is actually sold. So it is no wonder why they aren't interested in actually solving the problem, if they can sell you a replacement part that they know is going to fail, hence selling you another one down the road.
While there are some aftermarket options available, most of them are so similar in design as the factory unit, that they are not really improved and have the potential to fail in a similar way. Fortunately, there is an aftermarket option that actually solves the problem utilizing an all new way of thinking about heat exchangers.