With the 1991 release of the Rodeo, Isuzu found itself slightly ahead of the pack in building comfortable-to-drive SUVs. The 1996 Rodeo came standard with a 120-horsepower, 2.6-liter four-cylinder and had an optional 190-horsepower, 3.2-liter V-6 available. As a part of basic maintenance, Isuzu recommended replacing the engine coolant every 30,000 miles. To make draining and refilling the coolant easier, Isuzu mounted a small drain plug on the bottom of the radiator. When performing this task, keep the coolant away from children and animals, as coolant is highly toxic.
Allow engine to cool to the touch, if needed. Open the Rodeo’s hood and unscrew the radiator cap from the radiator fill neck. Check the gasket and seal on the underside of the cap for cracks. Replace with a new one the cap if cracks exist.
Raise the front of the Rodeo with a floor jack and position jack stands under the frame rails. Lower the vehicle onto the jack stands.
Crawl beneath the Isuzu and find the radiator drain plug – the plastic thumbscrew – on the passenger side of the radiator. Set a drain pan under the drain plug.
Twist the drain plug counterclockwise about a half-turn to start the flow of coolant from the radiator. Twist the drain plug clockwise to close it once the flow of coolant stops.
Raise the SUV off the jack stands with a floor jack and remove the jack stands. Lower the vehicle to the ground.
Add 50-50 premixed ethylene-glycol-based (green) coolant to the radiator until the coolant level is within a half-inch from the base of the radiator’s filler neck.
Start the Rodeo’s engine and let it idle until the upper radiator hose feels hot, meaning the thermostat has opened. Allow the engine to run and each time the coolant level in the radiator drops, add coolant until the level is within a half-inch from the base of the filler neck – the level drops as air escapes the system. Tighten the radiator cap once the level remains steady.
Allow the vehicle to set until the engine is cool to the touch. Check the coolant level in the Rodeo’s coolant overflow tank. Lift the lid from the coolant overflow tank and add coolant as needed until the level reaches the “Max” line on the overflow tank. Close the coolant overflow tank lid. In total, the Rodeo holds 2.3 gallons of coolant when fitted with a 3.2-liter engine and 2.4 gallons with a 2.6-liter engine.
Take the old coolant in the drain pan to a local used automotive fluid-recycling center for disposal. Some auto parts stores take used coolant free of charge.
