While inspecting for engine issues, we see what makes SkyActiv engines tick.
Car engine teardowns are always fun; not only do we get to see and learn from the inner workings of a vehicle's beating heart, but we also don't virtually need to spend money for it.
Case in point: I Do Cars pulled the engine from a Mazda CX-30. The engine comes from a rental car with about 30,000 miles on the ticker. According to the repair order, the customer reported attempting to jump-start it, only to be met with unusual sounds and signs of internal engine failure.
Mazda has always been at the forefront of engine innovation and engineering, for better or worse. Under the hood of Mazda vehicles lay powerplants that can either run forever or frequently require repairs. Owners of cars with rotary engines can attest to that last part.
Then there's the SkyActiv engine. Mazda has been trumpeting the SkyActiv technology in its powerplants for its performance and fuel economy. Unlike most naturally aspirated, internal combustion engines, Mazda's SkyActiv gasoline engines achieve high levels of efficiency by employing a combination of technologies, including high compression ratios, direct fuel injection, and optimized internal components.
For a time, Mazda was so confident in the technology that it was one of the last hold-outs in the EV revolution. The Mazda CX-30 engine in the video has a typical compression ratio of 14:1 and makes 187 horsepower and 186 lb-ft of torque which is generally on the top end as far as naturally-aspirated engines go.
This technology can be seen throughout the I Do Cars video. With tight clearances and multiple bolts holding up the aluminum block engine, it ensures a tight seal for all the engine components. Notably, while the spark plugs appear relatively normal, with only slight wetness observed, they still can't explain the symptoms reported.
The timing chain is within normal operating parameters thanks to tight seals and rails. The piston and valve cylinders exhibit some corrosion due to coolant seeping in through the head gasket cover. Apart from that, the damage doesn't seem to come from internal causes. Everything on the inside is clean and looks exactly like what a 30,000-mile engine would.
This finding raises more questions about the underlying cause of the engine failure. Nevertheless, it was cool to see how the SkyActiv engine works.