Cummins Engine Recall

While certain 1999, 2000, and 2001 Cummins 5.9-liter engines have come to experience cracks on the side of the block, the engines are not under a recall. The cracks are caused by thermal expansion stress during cold start warm-ups.

The Cummins 5.9 engine block has a complex structure that is difficult to cast in the first place. The outside wall of the block features a tricky 45-degree angle, which means that when casting, a vertical core shift can result in an area with a thinner wall than the rest of the sidewall, which is the case here. The problem is further exacerbated by reduced coolant flow in the lower parts of the cylinders where the block counts on the coolant to transfer heat from the hotter combustion area and cylinder head to the lower and outer walls of the block.

This means that when you start your engine and take off without a long warm-up period, the coolant has not fully warmed and expanded the lower cylinder walls and lower outer wall of the water jacket. If thermal expansion does not occur evenly there will often be stress that can result in a crack. These conclusions were reached by the technicians of LOCK-N-STITCH Inc., the cast-metal repair company with over 30 years in the business.

LOCK-N-STITCH Inc. has since developed a solution that goes well beyond the problems caused by welding. To learn about the LNS products and repair kits, browse the other articles on LockNStitch.com. To speak with an expert at LOCK-N-STITCH Inc., just pick up the phone and call 800-736-8261 or 209-632-2345. Or email them at gary@locknstitch.com. LNS has the knowledge and the resources to help get your Cummins engine fully repaired.