The DF104 utilized a distributor-type injection pump, typically manufactured by CAV (a Lucas brand) or Bosch. The pump fed fuel into a pre-combustion chamber. While this indirect injection system meant the engine started easily in cold weather (a plus for French winters), it also meant the engine was slightly less fuel-efficient than direct-injection rivals.

When people hear "Renault," they usually think of the iconic 4CV, the hatchback-breaking R5, or the Espace. But the true backbone of Renault’s industrial success lay in its green machines: the tractors. Buried deep in the engine manuals is the Renault DF104—a diesel engine that defined an era of farming reliability.

The DF104 is a naturally aspirated, 4-cylinder diesel engine produced by Renault’s industrial division (Saviem) in the late 1960s and early 1970s. It displaced roughly 3.2 liters (approx. 3,197 cc) and produced a modest but sturdy 50-55 horsepower.

You won’t find this engine in a sports car. Instead, look for it under the hood of:

No engine is perfect. The DF104 suffers from two known issues:

The DF104 is most famously bolted into the Renault 551 and Renault 651 tractors.

The Renault DF104 has a cult following in French "tractor pulling" (tire au tracteur). Stock DF104s are put into "Light Modified" classes. Enthusiasts have managed to push the naturally aspirated 3.6L to 120+ horsepower by adding turbochargers (though this requires internal modifications and water-methanol injection to survive).

There is also a famous story from the 1980s: In a remote area of the Massif Central, a farmer’s DF104 ran for 48 hours continuously to power a grain dryer during a critical harvest. The water pump seal failed, and the radiator emptied. The farmer kept pouring cold water into the cooling system while it ran. The block never cracked. That is the legend of the DF104—it doesn't stop.