WATCH: Toyota GR V6 Engine Teardown Shows How A Reliable Engine Met Its Demise

Toyota's 4.0-liter 1GR-FE V6 mill - found on models like the 4Runner, Tacoma, Tundra, and the well-loved FJ Cruiser - is renowned and admired for its outright reliability. So when YouTube channel I Do Cars acquired a blown 1GR-FE from a 2007 4Runner, we knew a teardown would prove to be exciting in pursuit of diagnosing what killed it.

Before the teardown began, Eric mentioned some information that could've led to the demise of the V6. For one, the power plant already had 186,000 miles on the odometer and had flood damage.

The first order of business was removing the spark plugs, which can be done without removing the intake manifold. But he eventually had to remove the intake manifold to see and inspect the intake port and valves for any damage.

The engine was looking fine, apart from the few spots of rust, which likely resulted from the flood damage. After removing the left-hand valve cover, Eric discovered incorrect cam lobe positioning, causing the intake and exhaust valves to remain open simultaneously.

Upon removing the timing cover, the timing system appeared to be in good condition. The teardown continued with dismantling the camshafts, where no significant damage was found besides typical war patterns. While parts of the cylinder heads looked optimum, Eric immediately saw a problem with one of the cylinders within the block that was not cranking.

The YouTuber had to remove the oil pan before getting access to inspect the cylinders, and he did not like what he saw.

When he got to the pistons, he discovered a broken rod - not just bent but completely snapped in two. Aside from damage to the block from the snapped con-rod, the cylinder walls, crankshaft, and caps looked almost fine.

The YouTuber concludes that it was water entering the engine that caused the rod to break since liquid cannot be compressed. It also highlights the dangers of trying to turn over an engine that is hydrolocked. That shouldn't discredit the 1GR-FE's reliability factor, and it's sure to remain popular among Toyota fans.

Despite its popularity, it seems unlikely the 1GR-FE will return in the next-gen 4Runner, as instead, the newcomer will downsize to turbo and tuo-hybrid four-cylinders paired with the new Tacoma's six-speed manual gearbox.