Everything To Know About Kohler Liquid-Cooled Diesel Engines

The Kohler Company, founded in 1873 as a manufacturer of cast iron bathtubs, now has manufacturing facilities spread around the world. Following World War I, rural Americans desired modern conveniences, with electricity being a big one. In an attempt to meet that demand, the Kohler Company moved beyond its more rudimentary cast iron technologies and developed the Kohler Automatic Power and Light "power plant" generator in the early 1920s, launching its Global Power Group, later renamed Kohler Energy, in the process.

While modern technology like the Kohler Power Reserve Energy Storage System aim to deliver whole-home electrical backup power, Kohler's liquid-cooled diesel engine generators offer off-grid and emergency power solutions for marine, residential, commercial, and industrial applications. In addition to generators, Kohler Power's current lineup of diesel engines powers a wide range of equipment including air compressors, farm and construction equipment, water pumps for irrigation and firefighting, wood chippers, and more.

Kohler Engines, part of Kohler Energy, manufactures its lineup of liquid-cooled diesel engines in its Reggio Emilia plant, located in Italy. However, some things could change with the May 2024 announcement that the Kohler Company and Platinum Equity are establishing Kohler Energy as an independent business. While it's unlikely that the new Kohler Energy company will move its engine manufacturing plant anytime soon, possible shifts could be on the horizon.

Kohler's current lineup of 18 liquid-cooled durable diesel engines includes six new models. There are also three retired liquid-cooled diesel engines listed on the Kohler Engines website for reference. The most powerful model in the current lineup is the 141 horsepower KDI3404TCR-SCR, with a 3,359-cc (205 cubic-inch) displacement and 479 lb-ft of torque. The least powerful liquid-cooled diesel Kohler engine, the model KDW 502, displaces 498 cc and delivers 10.7 horsepower. Applications include use in generator sets, all-terrain vehicles, and mini excavators, among others.

The newer liquid-cooled diesel engines include the Kohler Hybrid Energy Module, or K-HEM, series, which combines up to 75 diesel horsepower and 27 peak electric horsepower to deliver "quiet, compact, and efficient power," according to the official listing. In addition, the new KSD1403 series includes three versions of Kohler's 25.7-horsepower liquid-cooled diesel engine promising worldwide emission-compliant operation.

Every liquid-cooled Kohler diesel engine is backed by a factory warranty. The length and scope of each engine warranty is specific to the model, application, and whether it's used for commercial or personal purposes.

The warranty requires periodic maintenance of the engine, including changing the crankcase oil per the schedule prescribed in the owner's manual. This kind of attention can also help your diesel engine last longer. The Kohler KDI3404TCR-SCR owner's manual, for example, requires changing the air, fuel, and oil filter cartridges and the engine crankcase oil every 500 hours of operation. Kohler recommends its own proprietary 5W-40 engine oil for its diesel engine powered generators. This particular engine takes 15.6 liters of oil to fill the crankcase.

For comparison, the KDW502 owner's manual requires air and oil filter cartridge and engine oil changes every 125 hours with fuel filter changes at 200 hours. The standard oil sump requires 1.4 liters of engine oil to fill its crankcase.