The Root Of The Problem
He tells the story of a friend who ran a tow truck company that used 6.0s. He says, “He was having fits with them, so he brings them to me. I of course think, ‘I can fix them, I’m the smartest guy I know!’” They put new OEM parts on one of them and replaced the bad EGR cooler. 5,000 miles later, which in the life of a tow truck is only about a month, the truck came back with the same problem. They thought that Ford just made a faulty part, so they replaced it again, at their own cost of time and money, and sent it back on its way. Another four weeks passed and the same truck came back AGAIN with the same problems. “Now we’ve eaten our lunch twice on it, and it’s still not fixed and we don’t know what the heck’s going on with it,” he recalls.
They sent the part to Ford and tried to get to the bottom of the situation. Ford replied and told them the oil cooler was the problem. “That’s a crock! No way!” Ken exclaims. “Then we started doing some research, and we found out that in fact, it really IS the oil cooler that’s causing the problem.” Or at the very least, any problems with the oil cooler will get passed on to the EGR cooler, because according to Ken, the stock EGR cooler is on the “ragged edge of failing right out of the box.” If the interior of the core overheats, it exceeds the strength of the materials that hold it together and it essentially tears itself apart.
Let’s back up. The oil cooler, in simple terms, is made up of alternating layers of channels for the coolant and the oil. The oil layers are larger and the coolant layers are about half as big. If you can see where this is going, pat yourself on the back. The smaller coolant layers get plugged up pretty easily, and they found that it only takes a 10 percent reduction in coolant flow in the oil cooler to cause the EGR cooler to fail. So what’s wrong with the EGR cooler that causes it to have such a small tolerance for error?