How much piston damage is ok?

A piston is a moving component that is contained by a cylinder and its main purpose is to convert heat energy produced in the engine to linear motion which ends as rotational energy that allows the car to move.

Like other engine components, the piston usually gets damaged over time and thus needs to be replaced. But a question that some automotive enthusiasts are asking is how much damage is ok for a piston? Continue reading to find out more.

So, how much piston damage is ok?

Every car component has its limitations when it comes to how much damage it can withstand and the same also applies to the piston. The piston can only handle damage up to a certain point before it completely fails.

So, piston damage is ok only if it does not affect the performance of the engine. The damage should also not involve the piston rings. If the piston gets damaged then it will result in oil finding its way into the combustion chamber causing more issues for the engine.

Damages that a piston can suffer

There are many damages that a piston can suffer. Below are common piston damages that your car is likely to suffer from.

1. Piston ring failure

The piston ring is a component that seals the gap between the cylinder and piston. It also controls the oil that lubricates the cylinder and dissipates heat away to prevent overheating.

When they wear out, they can reduce the engine performance as well as increase exhaust emission. Piston ring failure can also cause piston slap (noise caused by excessive rocking of the piston).

Additionally, it can also allow oil to leak into the combustion chamber thus causing engine failure.

2. Piston crown damage

Piston crown damage occurs when a detonation in the valve or combustion chamber comes to close or falls on the crown. The Crown is located at the top of the piston and its damage can be devastating to the engine performance.

3. Piston skirt damage

A piston skirt is a component that helps to balance the piston in the cylinder. This device is coated with a low friction material to allow seamless piston operation.

However, if the skirt wears out or deforms, it can increase piston clearance thus affecting the engine performance.

4. Cracked piston

A cracked piston occurs as a result of using low-quality fuel or failure of the exhaust gas recirculation system.

5. Burned piston

A burned piston can be spotted instantly when you remove the top of the engine. This problem usually occurs when you use dirty fuel injectors.

6. Snapped timing belt

A timing belt is a crucial component that keeps the valves and pistons in perfect alternating time. If the belt snaps, it can cause a collision causing further damage to the piston.

Out of the damages listed above, piston ring failure is the most lethal and will damage the piston faster. The reason why piston ring failure is the worst of all is that it allows oil to leak into the combustion chamber causing the piston to wear out faster.

How do you know if pistons are damaged?

Pistons usually work in extreme conditions which impact their performance over time. Below are signs of a damaged piston.

Decreased engine power

One of the main signs that indicate your piston is damaged is if there is decreased engine power. When your car piston is damaged, the engine efficiency will decrease, resulting in decreased power.

This means that your car will struggle to accelerate. A damaged piston can also result in oil seeping into the piston or increased friction all of which reduces efficiency.

Strange noise from the engine

Another sign that the pistons are damaged is if you hear squealing noises coming from the engine. This noise is usually generated when the piston slaps.

A piston slap is when the outer boundary of the piston slides with the inner cylinder wall. It also occurs when the piston shape changes because of increased friction.

White smoke coming from the exhaust

Perhaps the most visible sign of a damaged piston is white smoke coming from the exhaust. When the piston is damaged, the oil will leak into the combustion chamber and mix with the fuel. The additional burning in the combustion chamber is released in the exhaust in the form of thick white smoke.

Decrease compression

A damaged piston will allow extra air to penetrate inside the cylinder thus reducing the compression ratio.

More oil consumption

When the piston is damaged, you will notice that your car will consume more oil. This is because a damaged piston will leak oil into the combustion chamber, resulting in more oil consumption.

Can you drive with a messed-up piston?

Practically, yes, you can drive with a messed-up piston, for a short while, but I don’t recommend doing that, because the damage inflicted on the engine can be significant.

If you don’t repair or change the damaged piston in time, will damage the engine. A messed-up piston will not stall the car immediately unless the damage is serious.

So, if your piston is damaged, then it is just a matter of time before it completely breaks down. If you notice that your car has a damaged piston, make sure it is fixed as soon as possible to prevent it from causing further damage to your engine.

Can you reuse a damaged piston?

Yes, but it is not recommended. Reusing a damaged piston will save cost but will do more harm than good to your engine. A damaged piston will not seal properly and that will reduce the efficiency of the engine.

Oil will also leak into the combustion chamber, thus forcing you to use more oil. So, although it is possible to use a damaged piston, it is not a wise decision because it will not last for long and will also inflict more damage to the engine.

How much does it cost to repair a damaged piston?

The piston is one of the most expensive components of the engine. So, if your piston is damaged, it will cost you a lot of money to replace it.

The average cost of piston replacement can even be $1000 and $2000 depending on your car type and model. The main reason why repairing a damaged piston is so expensive is because it involves a lot of work to disassemble the engine and install new pistons.


Piston damage is a serious issue that should not be ignored because it can result in engine failure. If your car shows the symptoms mentioned above, then chances are that the piston is damaged and needs to be repaired. Take your car to a trusted mechanic to have them replaced to avoid compromising your car’s engine performance.

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