Repair Methods for a Cracked Block

An engine block in a vehicle is responsible for protecting and securing the combustion components of an engine. The engine block is typically very durable and resistant to heat and cold. However, if the engine begins developing smoke or other symptoms, it could have a cracked block. If it has been determined the block is cracked, there are various methods to repair it, some more expensive than others.

Epoxy

Metal epoxy can be used to repair a cracked engine block, depending on the severity of the crack. The epoxy would act as a putty to fill in the crack. If an epoxy is used, it is important to keep in mind many epoxies have a 24-hour cure time. Also, the epoxy needs to be suitable for using in vehicle engines and able to withstand high temperatures in the engine. There are epoxies available made specifically for vehicle engines.

Engine Sealants

There are many chemical sealants available specifically made to seal a cracked engine block. Directions vary according to the sealant manufacturer, but the basic process is the same. The radiator will need to be drained and the sealant poured into the radiator. The vehicle should run for at least 30 minutes for the sealant to run through the vehicle and seal the crack. After running the engine, the excess sealant has to be drained and the radiator fluid replaced.

Welding Engine

Another option for repairing a cracked engine block is welding although this can be difficult. Welding a cast iron engine block is not an easy process because the entire engine block has heated to at least 1,000 degrees Fahrenheit before it can be effective. Even if the crack can be welded, often times it returns a short time after it has been repaired. This also should only be done by an experienced welder.

Rebuild/Replace

If the crack is too large for epoxy, sealants or welding to be effective, it can be rebuilt. However, this method depends on the size, location or severity of the crack. This also should only be done by an experienced mechanic and is one of the more expensive options.

If none of the above options are a possibility, replacing the engine block may be the most viable option. However, the value and condition of the vehicle should be considered before pursuing this since it is the most expensive option.

Considerations

It is important to note that epoxy, engine sealants, and welding are temporary options and may not be a permanent fix. These are less expensive options if the vehicle is older and it is not worth putting a lot of work into it or rebuilding the engine block.