Uncovering Internal Rust and Overheating Damage in Mazda Skyactiv-G 2.5 Engine

TLDR; A teardown of a Mazda Skyactiv-G 2.5 CX-30 engine with only 30,000 miles revealed internal rust, coolant issues, and potential overheating damage. Despite some design features, the engine showed signs of wear and tear, indicating a potential overheat event.

⚙️ Rare Find: Skyactiv-G 2.5 Engine

The Mazda Skyactiv-G 2.5 CX-30 engine teardown is a unique opportunity due to the rarity of these engines.

The speaker notes the scarcity of failed Skyactiv engines and the unusual internal damage caused by engine design or neglect.

Despite the low failure rate, the teardown aims to uncover the interesting aspects of this specific 2021 Mazda engine.

🔍 Initial Inspection

The teardown begins with the removal of the spark plugs and inspection of the internal components.

The original spark plugs show minimal damage, and initial checks of the engine's rotation and intake ports reveal unexpected rust and moisture.

The engine's history as a rental car raises questions about its previous usage and potential impact on its condition.

🔧 Engine Components

The speaker evaluates the internal components such as the valve cover, timing system, and chain tensioner.

The timing system appears to be in good condition, and the speaker notes the unique advancements in the Skyactiv engine design.

Despite the engine's low mileage, signs of moisture, rust, and unusual wear raise concerns about its overall condition.

🛠️ Deeper Inspection

The teardown progresses to deeper inspection, involving the removal of the cylinder head, pistons, and other components.

The examination reveals unexpected findings, including coolant and carbon mixture, gunked-up pistons, and signs of potential overheating and damage.

The condition of the components, such as the cylinder head and bores, prompts further analysis of the engine's history and potential causes of damage.

🔬 Crankshaft and Bearings

The inspection extends to the crankshaft, rod bearings, and pistons, revealing signs of wear and damage in specific cylinders.

The speaker highlights the unexpected issues discovered in certain cylinders, indicating potential coolant and carbon contamination.

The findings prompt an in-depth analysis of the engine's condition and potential causes of the observed damage.

🔍 Root Cause Analysis

The speaker conducts a detailed analysis of the cylinder head, bores, and potential causes of the observed damage.

The examination reveals areas of concern, including potential cracks, distortion, and damage due to overheating and coolant issues.

Despite the challenges in identifying the exact cause, the speaker presents a comprehensive assessment of the engine's condition and potential factors contributing to the observed damage.

⚠️ Conclusion and Reflection

The teardown concludes with a reflection on the engine's overall condition, potential overheating, and the need for extensive repairs.

The speaker highlights the engine's design features and potential value of salvaged components, despite the significant damage observed.

The teardown provides valuable insights into the condition and potential issues of the Skyactiv-G 2.5 CX-30 engine with only 30,000 miles.