The New Process of Breaking in an Engine

Procedures for "breaking in" new, remanufactured or rebuilt engines are evolving. Standard procedure in past decades was to use break-in oil in a "new" engine for the first 100 hours. During that time, it was recommended to vary engine rpm and load, and to run the engine through multiple heat/cool cycles.

That was then. New ring and cylinder wall metallurgy, combined with improved break-in oils, require different strategies. Because the latest generation of piston rings and wet sleeves are "harder," it takes longer to seat the rings. Deere, Cummins and other engine builders now recommend a break-in period of up to 500 hours before switching from break-in oil to standard multi-grade engine oil.

Engines WILL burn oil during break-in. It's essential to add only break-in oil during that crucial period. Break-in oil is designed to deal with the fine and microscopic debris created as rings seat. Oil consumption will eventually decrease after somewhere around 500 hours as rings seat, signaling it's okay to switch to standard multi-grade oil designed to optimize engine performance and longevity.

As for how to treat an engine during break-in, a veteran John Deere service manager recommended, "Don't pull its guts out, but load it and work it. The one thing you don't want to do when breaking in an engine is let it sit and idle. If it's not being worked at full load, or at least variable mid-to full load, it can glaze the rings and cylinder walls and you’ll have an oil-burner on your hands."