When you really push engines hard, there’s going to be parts failures. Piston failures happen all the time, but do you know what can lead to a piston having problems? The truth behind broken pistons goes deeper than you might think, and we’re here to talk about it.
Other Parts Will Break The Piston
Anybody who’s had an engine go through a high-energy engine disassembly that wasn’t scheduled wants to know what caused it. You can usually figure out what the culprit was, and if it’s piston-related, there might be some additional causes. Contrary to popular belief, the piston itself isn’t always the reason a piston failure occurs.
One of the most common ways a piston’s life comes to an end has something to do with other parts stopping by for a visit. A dropped valve, connecting rods snapping, and rod bearings locking up are just a few of the things that can cause a piston to fail.

Dirt and debris that get into your engine can cause significant damage to a piston. It will cause serious wear to the piston skirt and rings. That’s why it’s important to clean your engine parts before and during assembly
Brandon Burleson from MAHLE Motorsports explains why these types of failures usually result in pistons being sent back to them in multiple pieces.
“We see pistons sent back to us for analysis all the time after a failure that were taken out by something else inside the engine. Contact with the piston inside the cylinder just happens to be the end game. What we do is then try to figure out what failed first that led to the issue for the customer. It’s actually helpful for us to get the rest of the connecting rod, valve, or whatever else was in the pan. The reason is because a lot of times, that’s what fails first, but if we only get back the piston, it’s hard to diagnose what caused the failure.”
Abnormal Combustion
A piston feels the full force of the combustion process. Abnormal combustion, whether it’s detonation or pre-ignition, can cause a piston to fail. Signs of this will show on the crown or fireland of the piston as pitting or erosion. The abnormal combustion will lead to the ring lands or the center of the piston crown to crack on its way to total failure.
Abnormal combustion and detonation will do a lot of damage to a piston.
“Typically, an abnormal combustion issue is something that’s outside of the piston’s control. This can be caused by a parts failure, a tune-up issue, or it’s a case where the piston is being used in the wrong application. If something changes the octane rating of the fuel, like oil in the combustion chamber, or you’re just using the wrong fuel, it will create abnormal combustion problems. If you’re lucky enough to catch this during routine maintenance, you can save the piston. If not, it’s going to lead to cracking and failure,” Burleson says.
These issues are typically the result of an incorrect air/fuel mixture, the wrong heat range for the spark plugs, too much advance on the ignition timing, the wrong fuel octane, and elevated air inlet temperatures.
Here's a great chart that shows all the different types of common piston failures and what causes them.[
It’s Getting Hot In Here…
If you create a blowtorch situation inside the cylinder, your piston is going to have a bad time. When you expose a piston to abnormally elevated levels of heat, it’s going to fail, no matter how well it’s designed.
“Pistons don’t like extreme levels of heat in the combustion chamber. There’s a limit to what they can deal with, and when you exceed that, that’s when you’re going to see these melting issues. An injector failing is one of the big causes of pistons getting melted. A bad tune will also cause these types of problems because the air/fuel mixture will be so far off. If we see on,e it looks like there’s been a torch that’s run through the middle of it, that’s usually a lien condition,” Burleson explains.
A piston is designed to deal with a certain amount of heat. Too much heat will melt the crown and top land, or it will cause skirt seizure.
Mind The Skirt
The fourth main cause for piston failures that Burleson wanted to cover is any type of piston skirt seizure. This issue will be caused by overheating and can show up on just one skirt of the piston. Now, if there’s insufficient piston-to-wall clearance, you can see the evidence of skirt seizure on both piston skirts.
“Cooling system problems can cause overheating-related skirt issues. You’ll get a hot spot that breaks down the oil film on the cylinder wall, and that’s what leads to the skirt damage. If the cylinder wasn’t machined right, or the wrong piston was selected, these can be other causes for skirt failures. Another cause could be the incorrect piston for a power-adder application, which will lead to skirt failures,” Burleson states.
Saving The Slugs
There are some basic things you can do to help ensure you don’t activate the piston delete sequence inside your engine. Most of these items revolve around correct parts selection, common sense, and basic maintenance. Remember, it’s the small things and details that prevent disasters in a high-performance engine environment.
Let’s look at parts selection first. Just because a piston is the correct size doesn’t mean it’s the right fit for your build. Everything from the material to the design of the piston needs to be taken into account to avoid issues once the engine is assembled and running.

You need to make sure the piston you select is going to work for your application. For example, a boosted piston that you order from MAHLE should be made of a 2618 alloy that’s stronger and can handle boost better
“The most important thing is to match the piston to the application or intended usage. If you buy a piston from us, but don’t tell us that you are going to spray it with a 500-shot of nitrous, then that is a recipe for disaster. If we know that you are going to spray it, then we can do things like moving the top ring down and increasing the crown thickness to help avoid failure issues. We also have a thermal barrier coating that we can apply to help keep heat out of the piston,” Burleson explains.
Looking at the common sense part of the equation, starting with a safe (rich) tune and dynoing the engine before you really beat on it is a good idea. The more you can do to make sure the air, fuel, and timing are all in a good spot will assist with avoiding any possible piston damage.
A good tune will prevent a lot of the issues that cause piston failure.
“Having a safe tune in the car when you first start it really is important. The last thing you want to do is drive the car, or even run it hard, when there’s a lot of detonation. That detonation will destroy a piston in a hurry, so do whatever you can to avoid that situation,” Burleson says.
If you don’t install all of your engine components correctly, there’s a real good chance they’ll start to self-clearance at some point. Once that starts to happen, it’s only a matter of time before you run into the situation we covered earlier about parts failing and taking out a piston or three. You can also add to this making sure you perform regular maintenance. By checking your engine over on a regular basis, you can catch problems earlier enough to prevent larger issues.

Not installing parts correctly will lead to a horror show like this. You can also prevent carnage by just checking your engine over on a regular basis.
“Regular inspections and maintenance are the foundation for preventing piston failures. For example, keeping track of your valve lash is a good indicator of how the engine is doing. If the lash suddenly changes a lot, there is probably something going wrong. Depending on your application, you should also rebuild or cycle out suspect parts such as rods and valve springs. All the little things add up and can save your pistons if you find a problem soon enough,” Burleson explains.
There are a lot of different things that can cause pistons to fail. Thankfully, you have the ability to prevent these failures by doing your research on what piston is best for your application, and taking the time to make sure your engine is always in tip-top shape. Remember, you have the ability to keep the expensive disassembly smoke inside your engine….