Originally Posted by PatO
I have the round EGR cooler and failures are very rare on that and it is not currently on the replacement list. It doesn't have the radiator fins like the square one does.
They still do fail though, and when they do, it isn't as apparent as the square style. They crack at the welds, so the coolant leak isn't bad compared to the square-style. The first 6.0 I did major work on had the round-tube style. It came in because the intercooler exploded. Root cause: super rusty turbo because of the leaking EGR cooler. It drove fine, other than needing frequent EGR valves, but his local dealer kept throwing EGR valves at it, never really digging deeper (leaky EGR cooler causes sticky sludge formation on the EGR valve). It lost all boost when the sticky turbo made end cap blow right of the rest of the intercooler. Root cause of them failing is still the same though.... lack of coolant flow from an obstructed oil cooler. His truck had "grellow" coolant because jiffy lube kept topping off his yellow coolant with green. And the new "grellow" coolant was full of tapioca since the silicates were precipitating out. Not much sand though, so it had clearly been flushed before, and it only had 78,000 when this all happened.