How Long Can You Drive With a Cracked Engine Block?

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A damage to your car’s engine is a serious situation that needs to be looked into, immediately. However, there are situations where you may not be able to act “too quickly” and as such, you’d want to know how long you’ve got before your engine gets wrecked (badly damaged).

How long can you drive with a cracked engine block? You can drive with a cracked engine block for as many miles as you wish, provided you’d always stop at intervals to top up coolant/water to keep the engine from overheating. In other words, cracked engine blocks can cause engine overheating.

This article explains everything you need to know regarding how a cracked engine block may affect your car’s engine.

How Long Can You Drive With a Cracked Engine Block?

A cracked engine block won’t stop a car from starting, and if you’re already driving when the block cracked, it won’t stop your engine from functioning. However, a cracked engine block would cause leaks, which would cause serious damage to the engine – if not fixed as early as possible.

Therefore, there is no particular length (mileage) you can drive with a cracked engine block before critical damage could occur on your engine.

The length you can drive depends on the severity of the crack, and where the crack happened. If the crack got into the cylinder, you may likely not drive up to 20 minutes before the engine breaks down completely and stops working.

Another thing is, cracked blocks cause overheating, if you can control the overheating, you may get a longer drive time before any serious scenario may occur.

But then, it is important to note that as the engine keeps running with the cracked block(s), you’re putting other close components at serious risk – this is not advisable at all.

What To Do When You Have a Cracked Engine Block

Sometimes, a cracked engine block can only be fixed by getting a new engine; it could be a rebuilt engine or a completely new one. Practically, the worst has happened already – when you’ve got a cracked engine block.

In order to keep your car running for a longer time, remove the radiator cap so there won’t be any pressure in the cooling jacket, then refill water/radiator coolant at intervals (after every few miles) and you’d be able to drive a long time with the cracked block.

On the other hand, if the crack is not too severe, you could purchase a stop leak product and patch the cracked region, and your car’s engine should work fine. (Note: this is not a permanent fix; it’s just to give you more time before taking the car to a mechanic shop for a possible change of engine).

Frequently Asked Questions

Can You Repair a Cracked Engine Block?

Yes, you can repair a cracked engine block, but the cost of repairs typically goes above $1,300. Hence, you may want to consider getting a rebuilt engine or a new engine.

Will a Car With Cracked Engine Block Start?

Provided there’s enough water in the coolant reservoir, the car should be able to start and drive. However, you’d need to refill water at intervals to prevent overheating.

How Do You Know You Have a Cracked Engine Block?

Oil/coolant leaks, low engine compression, engine stalling, and overheating are all signs of cracked engine blocks. You may also get to see the crack appear physically when you look closely at your car’s engine blocks.


How long can you drive with a cracked engine block? You can drive quite for a long time depending on the severity of the crack and where it happened. However, it is not advisable to drive with cracked engine blocks.

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