The 4JH1 is an Isuzu-made engine primarily used in Isusu heavy-duty and commercial cars, such as pickups and trucks. It’s a 3.0-litre inline-four diesel with a single turbocharger. Most notably, it is fitted to cars like Isuzu D-Max. The 4JH1 was first introduced in the early 2000s and has been a long-lasting unit, fitted to cars sold all over the world.
The figures could change depending on the exact variation, but the 4JH1 usually developed 96 kW of power and 245 Nm of torque, making it a solid workhorse in commercial applications. It’s a SOHC engine with 16 valves and indirect injection.
This engine is praised for durability and reliability. It has an 18.3:1 compression ratio, making it suitable for on- and off-road applications. Despite its popularity and reputation, issues with injector pumps and excessive timing belt wear seem to be the highest concerns. This is why used 4JH1 motors are in demand.