How To Repair a Cracked Engine Block

Cracked engine blocks in industrial diesel engines commonly used across the marine industry, in mining and heavy equipment and other heavy duty automotive and industrial trucks, usually occur due to a loss of casing integrity, which often causes cooling water leakage. This could be due to:

• Frost damage: When cooling systems are exposed to freezing conditions without adequate antifreeze protection, the water inside expands as it freezes, putting pressure on the block causing cracks.

Cavitation and corrosion: In poorly maintained systems where coolant flows are high speeds, cavitation can become a problem. Vapor bubbles can implode and damage internal surfaces. If this is combined with corrosion it can weaken the block and eventually lead to cracking over time.

Impact damage: Physical shock from collisions, dropped parts during maintenance, or operational accidents can cause structural fractures in the engine casing.

Industrial engines such as Caterpillar (CAT), Cummins and MAN Energy Solutions used across marine vessels, mining equipment, power generators, and heavy-duty vehicles, a cracked engine block can manifest through several operational and maintenance issues:

Pressure irregularities: Operators might observe abnormal pressure readings in the cooling system or crankcase due to cross-contamination or compression leakage.

Unexplained coolant loss or visible external leaks: Coolant escaping through hairline cracks in the engine block may result in puddles, staining, or pressurized leaks, especially noticeable after shutdown.

Overheating during operation: Reduced coolant circulation due to internal leaks can lead to abnormal temperature spikes or engine shutdowns caused by thermal overload.

Contaminated fluids: A cracked engine block may allow coolant and oil to mix, leading to milky or discolored oil, or coolant with oil contamination. This is often seen during fluid inspections or servicing.

Loss of compression or reduced performance: Internal cracks can affect cylinder sealing, leading to poor combustion, misfiring, or a noticeable drop in engine power.

In many cases, especially within industrial repairing a cracked engine block can be significantly more cost-effective than replacement.

A great example is the repair of a Komatsu 900 loader engine using Belzona 1111 (Super Metal)where a cracked engine block that would have cost $127,000 (at the time of the repair) to replace was instead repaired using less than 6 % applying Belzona products. The repair was completed in just four hours, minimizing downtime and saving both time and capital.

Read the case study here: https://khia.belzona.com/khia/_ENGINE_REPAIR_WITH_BELZONA

In industrial situations, replacing a large diesel or marine engine block can require extensive disassembly, long lead times, and lost production time. In-situ repairs using cold-applied solutions like Belzona, provide durable, fast, and cost effective alternative.

This solution does depend on the location and the extent of the damage and also the operating conditions. Contact a Belzona representative to find out more.

Yes, cracked engine blocks can be saved. One method which has been successful in industrial situations for decades is to use a product such as Belzona 1111 (Super Metal), Belzona 9341 Reinforcement Tape, and standard machine shop tools to repair hair line cracks. This solution not only restores the casing’s strength, but also avoids a costly replacement,  saving time, money, and operational downtime.