How to Fix Piston Slap? Step-by-Step Guide

Piston slap is a common issue for many car owners, and it’s not very pleasant to deal with the constant sound of it. In that case, repairing the slapping noise is a necessity if you want to enjoy a pleasant ride on your vehicle.

Luckily, the piston slap cure is a reasonably simple process. And with the proper knowledge and tools, you can do it as well in hours. But, you need to follow the accurate steps for it.

Below, we’ll go over an easy step-by-step guide on how to fix piston slap that you can follow to solve that annoying issue. Make sure to go over them thoroughly not to mess things up during the process.

piston slap

What is a Piston Slap?

A piston slap is a noise produced by the pistons in the car engine. Once that problem occurs, it starts to damage the engine, leading to more expensive repairs, which is not a good thing.

Luckily for you, the repair is not that hard, and you can do it for yourself if you have basic automotive engine parts knowledge. But for that, you need to have a clear understanding of what’s causing the problem and the right way to get rid of it.

What Causes Piston Slap?

Piston slap is caused by the pistons inside the engine going back and forth, making a constant noise that can get annoying pretty soon. Many think that it doesn’t damage any parts of a vehicle. But the fact that it creates a metal squeaking noise every moment you’re driving your car is pretty annoying.

The key reason of piston slap is worn cylinder walls or damaged pistons, generating a large space between the cylinder wall and the piston. When the clearance is high, the piston starts swaying side to side as well as makes noise. It is known as the piston slap.

However, piston slaps can damage the engine over time as it wears down the parts and bores, which can easily cause engine failure making your car die sooner than usual. So, you should take steps to solve this issue and deal with it when it’s still in its early stage.

How to Fix Piston Slap

Now that you understand what a piston slap is, and what causes it, it’s time to go over the steps on how to quiet piston slap easily. Below, we cover the step-by-step process you can follow and solve that issue for your vehicle. Without any further ado, let’s check it out right now.

Step 1: Get the Tools Ready

First, you need to get the tools ready for the job. You don’t need a lot of tools. A ratchet extension, a screwdriver, a socket wrench, and a tap and die set should be enough for the job. You’ll find these tools very easily in your local hardware store. You can also shop them online for more convenience.

Step 2: Open up the engine

Once you have the tools near you, it’s time to work. Start by removing the intake and exhaust manifolds from the engine, which might contain the leading cause of the piston knurling.

Step 3: Start inspecting thoroughly

After you open up the parts, it’s time to inspect them very carefully. The most obvious signs you’re looking for is the signs of overheating, corrosion, cracks, broken welds, etc. That should tell you that the parts are damaged inside, causing the slapping noise.

Step 4: Clean it up

As the system is open now, it’s good to clean pistons thoroughly. Start with the joints at connections, including the manifolds, rings, cylinder wall, and exhaust pipe, and work your way through the clamps to clean each part correctly.

Step 5: Make the necessary repairs

If you see that any part is damaged, now it’s time to make the repairs and do all the replacements. You might want to replace loose clamp bolts as it’s very common for them to get loose after a while. That should help to solve your problem of vehicle’s piston slap issues.

Step 6: Upgrade parts if needed

Upgrading your engine block parts is always a good idea to make it work better and more smoothly in the long run along with the piston slap fix. Go for good quality products as they will give you more longevity and better overall performance. That will cost you a little extra money but it’s totally worth it.

Step 7: Go for a new exhaust system

Replace your car’s exhaust system with a new exhaust system that’s more powerful and can operate with less noise. That’ll make your ride much more enjoyable, and it’s a significant upgrade to make for your car.

Step 8: Change the oil

As you might already know, changing the engine oil regularly is one of the most important maintenance steps you need to do to keep your car running smoothly. So, take your time and change the oil before reassembling the parts.

Step 9: Go for a good air filter

If you can, it’ll be a great time to install a high-performance and silent air filter on your car. That’ll make the vehicle run so much smoother with less noise.

Step 10: Install a more powerful ignition system

Finally, if you feel like the ignition system is causing piston smacks, you can always replace it. Make sure to go for a powerful one as it’ll help make things much better. Also, it’s well worth it in the long run and a great investment for your car.


Question 1: How long will an engine last with piston slap?

Answer: There’s no fixed answer to how long an engine will last with a piston slap. That’s because it depends on the vehicle that you’re dealing with. For every car, it can be a different number, and that’s why it’s impossible to tell precisely how long the engine will last with a piston slap. In some cases, the car might last up to 35,000 to 50,000 miles as well, and that depends upon the severity of damaged parts.

piston slap fix

Question 2: How do you test a piston slap?

Answer: After you’re pretty sure that your vehicle has a piston slap, it’s time to test it to confirm that. Now, answering how to diagnose it, you need to check the front engine and open the pistons. If there’s a piston whack in your car, the pistons will be worn off, and that’s a dead giveaway.

Question 3: What oil is good for piston slap?

Answer: Any oil that can help to cushion the piston to bore clearance will be a great oil to use for piston slap. However, you should also go for something high pressure as it’ll help to deal with the issue as well. Also, premium quality oil like Rotella T4 is a far better option than the cheap ones, and you should gravitate towards something that’s on the more premium end.

Question 4: Can overheating cause piston slap?

Answer: Generally, overheating won’t cause piston slap as that doesn’t directly impact the engine internal parts. So, you don’t have to worry about the overheating temperature of your car damaging your pistons, which is not a very common case.


The piston slap noise can undoubtedly become one of the most annoying things while driving a car. With its easy fix, there is no excuse not to try and repair it for yourself. But, you need to know the structure and functions of basic engine parts of a vehicle.

Hopefully, as you just went through our step-by-step guide on how to fix piston slap, you should have no trouble doing that for yourself. Make sure to follow the instructions accurately so that you don’t run into any issues while trying to reduce the noise.

But if you are not confident enough to do it yourself, then you can hire an expert mechanic by all means. That will cost you a little bit of money, but you’ll get an easy solution.


Mr. Rubel is an Engine Mechanic. He has more than 15 years’ experience on repair and maintenance of different kinds of vehicles. He is also providing training to mechanics and works as a Senior Mechanic of a well-known organization. He is sharing his knowledge to support the car lovers to solve the vehicle issues.

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