Is The Toyota 3RZ Engine Really As Reliable As Fans Say? This Teardown Takes A Closer Look

It's no secret that Toyota engines are renowned for reliability, with several Toyota models likely to run more than 250,000 miles. That reputation extends to the Toyota 3RZ-FE engine. This 2.7-liter four-cylinder saw use in Toyota models like the Tacoma, Hilux, and HiAce vans between 1994 and 2004 and is said to be just about bulletproof. The engine itself isn't much to write home about, at least on paper. It's a twin-cam, 16-valve  motor that made 150 horsepower and produced 177 pound-feet of torque.

However, there's a reason cars equipped with this powerplant, like the Toyota 4Runner, are consistently ranked as some of the longest-lasting vehicles around. This engine is particularly good at holding up in harsh weather and other extreme conditions, and its reliability is just about legendary. In fact, one YouTuber recently came across one of these engines in a 2002 Toyota Tacoma that had clocked more than 300,000 miles before being chucked out. In his teardown of the engine, he explained what went wrong and whether this engine could have squeezed out a few more miles before being put to rest.

On the YouTube channel I Do Cars, a mechanic opened up the engine to discover water and coolant had mixed in the crank case — making a substance he describes as "milkshakey." He also noticed some issues with the spark plugs that suggested the car's owner had more or less neglected to maintain the engine. Ultimately, the mechanic predicted that the water and coolant began to mix when a head gasket blew.

That sounds bad, and the engine has definitely seen better days. However, the host of the video said that after some cleaning, conditioning, and a new head gasket, he'd be able to get it running again. That's partly because this engine uses a timing chain rather than a rubber timing belt to drive the valves, and timing chains tend to last longer and be more durable. In this scenario, the timing chain guides were original and still perfectly capable of working if the head gasket hadn't been blown, the mechanic explained.

The inside of the engine was obviously worn but otherwise looked solid. Some wear and tear is to be expected, however, considering the engine had more than 300,000 miles. The teardown is worth watching in full. It's a testament to Toyota's engineering and shows how the brand made a drivetrain that runs longer than many of its competitors. Even if it isn't that powerful of an engine, the 3RZ-FE is as reliable as people say.