Originally Posted by the persuader
The 5.9 pistons aren't prone to failure. It's the fact that the commonrail injectors can stick open and melt a piston.
The 5.9 Commonrail used the same injectors as the LB7 Duramax and the LB7's had injector problems as well, but more common.
Most 5.9 pistons are not but fact is the 04.5-07 pistons are more prone to failure for several reasons.
Due to the design of the piston thanks to emissions those 3.5 years had the worst issue with failed engines mainly due to the piston design and material, one could fail an injector on an 03-04 and be way less prone to melt pistons like the 04.5-07, most engine builders use the 03-04 pistons when rebuilding CR engines and then puts in the 03-04 style injector nozzles as well to match the spay pattern to the bowl design plus the 03-04 injector is a 2 event injection versus the 3-5 events of the newer injectors.
Look at injector builders, most will not build an injector rated more than 100hp for the 04.5-07 for this exact reason, the pistons will not tolerate the heat.
Look at injector builders for 03-04 hp is unlimited because the pistons are better suited to the heat of extra fuel.
BBI makes the best of the best in CR injectors for the common rail now but they come with a healthy price as well.
read up on BBI here, lots of good CR injector info on the site. http://www.bigbanginjection.com/
Also check out smarty resource forum for more CR injector info.
Filtration is the key to CR injector life with added 2 stroke oil helps the life as well.