There are automotive problems that require very easy fixes. For example, if you have a cracked radiator hose, it is very easy to replace it with a new one. A blown fuse is also very easy to address with the insertion of a new fuse. Worn brake pads? Remove it and replace it with new brake pads. But if you are talking about a crack in your engine block, it would seem as if it’s already the end of the world. You know the very nature of your car’s engine. If there’s a crack, this automotive component loses its structural integrity. There is no question that fixing a cracked engine block is not easy. Its repairability is contingent on the severity, extent, and nature of the crack.
What Does it Mean to Have a Cracked Engine Block?
The engine block is the structure that supports or contains a variety of components that operate the engine. It contains the cylinders that are crucial in the generation of power. It also contains the crankcase which is important in housing the crankshaft. The crankshaft converts the linear (up-down) energy coming from the pistons in the engine cylinders into rotational energy. This delivers power to the wheels to get the vehicle moving.
Other important components include passages for both coolant and oil. Coolant helps prevent engine overheating so that it can maintain optimum working function. Engine oil serves as a lubricant for the different metal components of the engine. This helps reduce friction, which can also help in the prevention of overheating.
Since the engine block contains these components and many others, it is often constructed of the toughest possible materials. There are two fundamental materials that car manufacturers use in the design and construction of these automotive parts. Majority of engine manufacturers uses solid blocks of cast iron to give it a very rigid and sturdy platform for the different components. The problem with cast iron is that it is very heavy. As such, some manufacturers use aluminum alloy. This is lighter and can provide better heat management.
A cracked engine block often means a loss in the structural integrity of the structure that supports the cylinders, crankcase, fluid passageways, and many others. This can lead to a host of problems that can range from engine overheating to a reduction in engine performance. In worst cases, it may no longer be safe to drive your car as doing so can only worsen the problem or create other problems.
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Symptoms and Signs of a Cracked Engine Block
The main issue with a cracked engine block is that it can be very difficult to identify where the crack is. In some cases, the crack can be so small that you won’t be able to see them with the naked eye. Cracks can also occur either inside or outside of this part of the car. In either case, it will still be difficult to ascertain where the cracks are. Hence, you can only rely on some of the most common manifestations of a possible cracked engine block.
- Blue or Grayish-Black Engine Smoke
Smoke should only come out through the exhaust tail pipe. If you notice bluish or grayish-black smoke emanating from the engine bay, then it is a worrisome indicator of a cracked engine block. The issue here is that exhaust fumes do not pass through the car’s exhaust system. Instead, it passes through the crack in the engine block. For obvious reasons, this is not going to be the only symptom you will see.
- Engine Overheating
A crack in the engine block can create a miniature passageway for engine coolant or antifreeze to leak outside the block. Instead of the coolant circulating through the engine passages, it is leaking outside. As such, the engine overheats because of insufficient supply of coolant. You may notice white smoke coming from under the hood as well as a temperature gauge that seems stuck in the red.
- Mixing of Oil and Coolant
If you notice the buildup of white, milky gunk under the engine oil cap, this is an indication of a possible mixture of engine coolant and engine oil. The passages are separate from one another since oil and water do not mix. If there is a crack in the engine block, then it is possible that the coolant can leak into the passageways for the oil. This will manifest as milky-white greasy stuff under the oil filler cap.
- Poor Engine Performance
The engine block contains the cylinders that produce the power for the car. The cylinders allow the generation of power by containing controlled explosions within the walls of each cylinder. If there is a crack in this part of the car, then some of the energy from these controlled explosions can escape through the cracks. In other words, a crack in this automotive part can lead to low engine compression. You will notice very rough idling as well as a reduction in fuel economy.
Potential Causes of Cracked Engine Block
Modern engine blocks do not crack in a spontaneous manner. There is often a trigger that may cause it to form microscopic cracks. Knowing the potential causes of a cracked engine block can help car owners institute measures that will prevent such problems.
Ask any mechanic about what they think can cause this kind of automotive problem and they will tell you only one thing – engine overheating. Excessively-high temperatures can cause some parts of the engine to expand. While metals are strong, they do have breakpoints. When they reach a particular stress level, metals do break. Extreme temperatures can lower the stress threshold of metals, making them break a lot easier.
There are different reasons why an engine can overheat. Low engine coolant is one of the most common culprits. Failure of the water pump can also lead to engine overheating. The water pump is important in circulating the coolant throughout the engine. If it fails, then the coolant will not be able to remove excess heat from the engine.
Overpowering the engine can also lead to excessive heat-generation. Installing a turbocharger or a supercharger to an incompatible engine can also lead to overheating. Installing these devices produces more power than what the engine can handle.
This component of the powertrain can also crack because of excessively-low temperatures. When the coolant freezes in cold weather, it can push against the walls of the block. This can cause microscopic cracks.
A very rare reason for a cracked block is casting failure. This is always a manufacturing fault during the molding process. A sudden shift in the mold can lead to the fabrication of metal sections that are thinner than usual and compared to other sections of the block.
Possible Solutions to a Cracked Engine Block
As mentioned, fixing a cracked engine block is never easy. Everything depends on the severity and extent of the crack as well as the engine component affected. The following are some of the more common ways to fix this kind of problem.
- Re-welding
There are attempts to re-weld the block to help seal off the cracks. To pull this off, special welding rods and an arc welder are necessary. One has to remember that the engine block comes from one solid mass of iron or aluminum. It is not fabricated using different sections fused together. As such, welding the engine block creates an area that is more susceptible to cracking. There is also the risk of deformation.
- Cold Metal Stitching
If you have ever experienced having a torn fabric, you know that you can stitch the two sections together. This is the same principle behind cold metal stitching. The difference, of course, is that you are not stitching fabric. You are “stitching” metal. The issue here is that it may not be effective in sections of the engine that are frequently exposed to drastic temperature changes. This can tear the metal stitching and reopen the crack. It is also very expensive.
- Cold Welding Patches
There are products in the market that use cold welding technologies. In most cases, these use epoxies or adhesives which will form a strong seal in the cracks. There are also patches that people can apply onto the cracks. The problem with this approach is that they do not last long. One has to keep in mind that the engine can turn into a furnace. Like cold metal stitching, temperature extremes can damage these patches and re-expose the cracks.
- Commercial Sealers
Since the most common culprit of a cracked engine block is an issue in the cooling system, there are products that work to fill these cracks. These products are often introduced into the car’s cooling system. Over time, the chemicals in these products form a more permanent seal in the cracks. The issue here is that the products may not solve large cracks.
A cracked engine does not automatically mean you have to replace or rebuild your engine. Everything depends on the severity and nature of the crack.
Sources:
- Can You Fix a Cracked Engine Block? Here’s What You Should Know – Car Brain
- How to Fix a Cracked Engine – Do It Yourself
- Warning Signs of a Cracked Engine Block – Hye Tech Auto
