The 3RZ-FE is a 2.7-liter inline four-cylinder gasoline engine produced by Toyota from 1994 to 2004. It was a replacement for the well-known 22R-E and used mostly in commercial trucks and four-wheel drive vehicles such as Toyota Tacoma, T100, Land Cruiser Prado, 4Runner. After 10 years in production, the engine gave way to a new 2.7L engine - 2TR-FE.

The 3RZ engine has a deep-skirt cast iron cylinder block. Bore and stroke sizes are both 95.0 mm (square engine). The engine uses a forged crankshaft - fully balanced, with eight counterweights and a torsional damper pulley. Connecting rods are shot-peened and forged from carbon steel. The 3RZ also got aluminum pistons with resin-coated skirts. Inside the cylinder block, there are oil jets installed to spray oil on the bottom of the pistons for additional cooling. Engine crankcase is equipped with two gear-driven balance shafts.

On top of the engine block, there is an aluminum cylinder head with two overhead camshafts (DOHC layout). It has four valves per cylinder - two intake and two exhaust valves with 19 degrees included valve angle between them. The intake valve diameter is 37.5 mm; the exhaust valve diameter is 30.5 mm. There are no hydraulic lifters/buckets. Valve adjustment is provided by a shim over bucket arrangement (preferably every 25-30k miles). The 3RZ FE engine has a timing chain, which drives the intake camshaft only. The intake camshaft rotates the exhaust camshaft by a scissors gear. Camshaft specifications: intake duration - 230 degrees; exhaust duration - 224 degrees. The engine has a hydraulic timing chain tensioner and oil jet to lubricate the chain.

The intake manifold is made from aluminum alloy. It has by two intake runners for each cylinder, specially designed to increase torque. The engine got an electronically controlled, multiport fuel injection system and Toyota's Electronic Spark Advance (ESA) ignition which was able to determine ignition timing by the ECM based on inputs from sensors. The early engines had a simple distributor and one ignition coil instead of a coil pack.