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How to Remove Rust from Inside Engine Block

March 15, 2024 | Victor Lukasso

Your car’s engine block is a crucial element that supports its proper functioning. If you notice the formation of rust within it, it is imperative to address it promptly. Here are the steps you can take to deal with rust in your engine block.

Rust isn’t formed instantly but is a gradual accumulation of oil spillage, coolant, or debris inside the engine block.

It’s also vital that you know how to get rid of rust in your engine block before it starts depreciating the engine block.

Rust is mainly removed from the engine block by dipping your engine block inside a rust remover solution for up to 1 – 3 days before wiping it with a rag.


The practical knowledge isn’t common, but I’ll show you some of the significant causes and removal of rust inside your engine block.

Causes of Rust Inside your Engine Block

Most experts agree that the development of sulfuric acid, which results from the mixing of sulfur – primarily found in low-quality gas or oil – and water that makes its way into your engine – causes rusting of engine blocks in automotive engine systems. This mostly happens in the winter and can be attributed to water accumulation inside your engine block.

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The moisture buildup in these parts penetrates the oil covering and comes into contact with the metal surface of your engine block. Additionally, the engine system’s cooling system and metal surface rust as a side effect of this event.

This will also prevent oil flow into other parts of the engine, thereby causing an increase in rust formation.

Steel is used more often than iron in automotive systems because iron rusts faster. Therefore, engine blocks made of iron erode more quickly than those made of steel. Because of this, cast iron engine blocks undergo the procedure of rust removal more frequently than steel blocks.

Your surroundings, the steel alloy components, and the heating process applied to the steel all affect how quickly your engine block corrodes.

When should I clean my Engine Block?

Automotive experts recommend cleaning your engine blocks once you notice oil or grease leakage.

The engine performs most of the labor-intensive work required to operate your car’s many moving parts. Most of these components come into touch with oil, grit buildup, leaky fluids, road debris, and chemicals contaminating the engine. Due to this phenomenon, you can apply a coolant rust inhibitor to reduce the rate at which metal components corrode.

Also, it’s another thing to do the cleaning properly to remove the rust particles. Implementing improper cleaning will only increase dirt accumulation, blocking oil flow inside the engine.

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How to Remove Rust from Inside Engine Block

Cleaning the inside of your engine block is a technical task that should be done if you know how to get around your car’s engine.

However, you can take your vehicle to an auto engineer if you find the guide below tedious.

Remember, you could cause further damage to other engine components if you don’t do it carefully.

Notwithstanding, you’ll need a complete toolset to get into our car’s engine and start the cleaning procedure.

Some requirements for cleaning the inside of your engine block include a rust remover, a bowl, a clean rag, wire cups and brush, and a degreaser.

Once the above is intact, follow the below procedure to start the rust removal.

  • Disengage the engine block from your engine by removing any component in contact with them.
  • Disassemble the engine block (you should also know how to assemble it after the cleaning process)
  • Mix the rust remover into hot water (preferably) – you can also use cold water.
  • Immerse the dismantled engine block into the rust remover solution and leave it within 1 to 3 days for proper cleansing.
  • Brush off visible rust particles with the wire brush or cup.
  • Degrease the engine block to aid you with grease removal in vital areas.
  • Now, for oil leakage on other components such as the gaskets, filters, bearing, sleeves, and even on the engine block itself and fix them
  • Next, thoroughly clean the engine block using the rag immersed in hot water, then dry it off using another clean rag.
  • Finally, let the engine block dry off entirely before coupling it up.
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Start your engine and let it idle for 20 to 40 minutes once everything has been put back together. This will enable your engine to warm back up to operating temperature.


Cleaning your engine block is beneficial for cooling as well as appearance. Rusted engine block channels can lead to overheating problems that cannot be resolved by a more prominent radiator or a more effective water pump.

An engine block cleaning is also needed if you’re looking forward to selling out your vehicle.

However, as I said earlier, you’ll need to be guided by a professional mechanic, or you should have a basic knowledge of automotive engineering to pull this off.

This is a simple guide to removing Rust from Inside your engine block.

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Meet Victor Lukasso, the owner of V. Auto Basics. Through this blog, Victor Provides Insights on the latest tips, maintenance, repair, and techniques in the automotive world.