What Are The Main Causes of Cracked Engine Block And How To Fix It

Brandon Trenton

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What Are The Main Causes of Cracked Engine Block And How To Fix It

If you own a car, you would have found yourself dealing with automotive problems occasionally, around the year. Some of them are easy to fix, for example, a flat tire, failed spark plugs, dead battery, or broken starter motor, while other problems might blow your mind away. Yes, I am talking about a crack in your engine block. Your world would shatter, especially if you were planning a road trip with your friends.

In cases where you could fix such breakdowns, it not only affects the engine functionality but is a great hit on your budget. Even then, you would have no idea if your car will function as good as new.

Here are the Basics That You Need to Know About a Cracked Engine Block

What is the Use of Engine Block?

First of all, let’s talk about the engine block. It is a rigid structure that contains cylinder blocks, cylinder liners, and crankshaft mainly as well as coolant passages and oil passages sometimes. The cylinder block works as a major power generator while the crankshaft uses the energy from the piston to convert it into rotational energy. This generates power for the wheels to move, and in this way, you drive the car on busy roads.

Purpose of Coolants

For the other parts like coolants, it prevents the engine from overheating so that the engine can function smoothly.

Use of Coolant Passage

Now comes the coolant passage. It stores engine oil. This oil lubricates different metal components of the engine, which reduces friction. It works hand-in-hand with the coolant preventing the engine from overheating. In short, an engine block holds all of the major components of the car to function.

Engine Block Protects these Components

This is how an engine block works, and your car runs without a problem. To protect these components, these blocks are made up of tough materials. Most of the time, cast iron blocks are used. Cast iron is used around the world, not just for engine blocks but also for the design and construction of other components. The reason behind it is not just the rigidity but its cutting edge performance as well. However, it has been replaced by other metals as it is heavy. Aluminum and copper alloy is preferred to produce a vehicle of lighter weight. These materials also absorb much less heat than iron.

What Happens When Engine Block Is Cracked?

So now that you know the science behind the engine block, then let’s talk about what happens in the crack of the engine block. The engine block is perfectly round and smooth, producing power with least friction, of course, with lubrication. The coolant flows through the system to keep it cool, but an internal crack will cause the oil to mix with anti-freeze inside.

Leakage of Liquids Causing Overheating and Emission of Smoke

These cracks are barely visible. An external crack will leak these liquids outside. Most of the time, leaking goes unnoticed. So now you must have your answer to why your car was overheating and emitting smoke. Without a repair, driving with a cracked engine block will only make things worse.  

Finding Out a Crack in the Engine Block

The most common sign of a crack in the engine block is leaking. This, as stated above, usually goes unnoticed at first as the crack is minute, which is barely visible in normal situations. This is the actual problem, not just for recognizing the damage but to locate it as well. Leakage also causes damage in the structure supported by engine block. This delay can cause problems starting from an overheated engine producing low power to a complete engine overhaul.

1. Check If Smoke is Coming Out of the Hood?

If your answer is yes, then there is an issue. Remember, the color of the smoke is your hint for a crack. Your car will emit blue or grey smoke from the bonnet. You must be thinking about what causes this smoke. The crack does not allow the engine block to convey the fumes to the exhaust system. As a result, the steam passes out of the cracks, and you see the smoke coming out of the hood.

2. Is Engine Overheating?

The crack is too small to be visible for sure but large enough to cause leakage. As soon as a crack appears, the coolant starts to leak out of the system instead of circulating inside. The engine has no liquid flowing inside the car block to keep it cool. Upon driving, the engine heats up, and in the absence of coolant, nothing could reverse this temperature rise. You will soon witness white smoke.

3. Is there milky gunk?

When the engine block is intact, coolant and the engine oil flow inside their passengers. However, if there is an internal crack, then it is impossible for them to flow separately. Coolant from its compartment will flow into the oil chamber. As a sign, you will notice white gunk in the oil cap like a plaque as a result of mixing. Don’t confuse it with sludge just because it’s greasy. This is a serious concern. It is a sign of head gasket and engine damage.

4. Low fuel economy

The cylinder in the engine block delivers power to the piston resting on it, making your vehicle move. However, when there is a crack, some of the energy is lost from them. These cylinders fail to deliver the same amount of pressure to the piston for compression.

Now the equation appears something like this: less energy delivered will result in low engine compression. This, in turn, results in poor engine performance. This is when your car starts consuming more fuel than average.

What Are the Main Causes of Cracked Engine Block?

The modern engine would not crack suddenly. There has to be an alarm before the actual crack is triggered. Look for the microscopic cracks that may be formed. If you know the probable causes as to why the engine cracks, it may help the owners to keep preventative measures intact.

1. Engine Overheating

If you would ask a mechanic or any car specialist, as to why the vehicle or automotive is not functioning smoothly, they quote one root cause: engine overheating. Extremely high temperatures can lead to expanding some parts of the engine. Every metal has a breaking/ cracking point. Once they reach that level, they are bound to break. Not just that, rising temperatures also compromise the level of stress they can bear, and you know what happens next.

2. Low Engine Coolant

Engine overheating can be caused due to various reasons. Low engine coolant is the most common of all, followed by water pump failure. The water pump is crucial to keep the coolant circulating in the engine. Even if the coolant level is not low, a failing water pump will do you equally worst, if not more.

3. Turbo Installed to an Incompatible Engine

A turbo/ supercharger installed to an incompatible engine also causes overheating, and do not forget: overheating is bad. It leads to excess heat production, and obviously, it’s not what your automotive engine can handle.

4. Extremely Low Temperatures

Remember, neither too high nor too low. The engine block may also crack due to extremely low temperatures. The coolant can freeze in cold weather and cause microscopic cracks by pushing against the walls.

5. Casting Failure

Casting failure does the same deed, but it is a rare occurrence. It is a manufacturing fault caused by an uncalled shift in the mold that leads to some parts of the metal is thinner than the optimum thickness in proportion with other parts of the block


How to Fix a Cracked Engine Block?

Now that you are stuck in this situation, don’t drive the broken automotive. Rush immediately to the mechanic. You might think that it’s not worth fixing this cracked engine block. Honestly, this also depends on the extent of the damage.

1. Re-Welding

Blocking this crack with an attempt to re-weld could be an option. All you need is an expert who knows arc welding and the use of special welding rod to start with. It’s easier to do when the block engine is made up of iron cast. Aluminum welding has its own cons as it is more prone to cracking. The iron cast is no exception to this risk. Deformation is another aspect that you have to look for.

2. Cold Metal Stitching

Cold Metal stitching works just like stitching your torn clothes. It is a unique repair method especially helpful during an emergency. This process is carried out under high temperature to join the cracked sides again. It has the edge over re-welding as it works well for cast iron and aluminum.

With little or no stripping, you can get it fixed in no time, but it might cost you a lot. Being exposed to high temperatures might cause damage to some parts. The crack might reopen later on due to deformation.

3. Cold Welding Patches

Sometimes we use glue for sticking two pieces together. For engine block cracks, adhesives are used just like a bandage. A strong seal is formed with the help of cold welding technology. The crack is sealed firmly with some patches. In the longer run, you would need another solution because this will cause the engine temperature to rise. After some months, the crack will reopen, then you have to rush to the mechanic again.

4. Commercial Sealers

Ever tried filling up the cracks in the wall with the cement? It works in a similar way. Sealers are introduced in the cooling system to fill these cracks over time. Later on, it forms a permanent seal. Again, this is not a one-for-all solution as it doesn’t work for large cracks.  

Now that you know everything about a cracked engine block, all you need to do is keep a strict check and get it inspected and repaired before it’s too late.