Subaru vehicles are known for their quality and performance, but like all vehicles, they are not immune to issues. One common issue that Subaru owners or potential buyers may encounter is piston slap. This article will explain what piston slap is, its symptoms, how it can affect the performance of a Subaru, the underlying issues that cause piston slap, and how to prevent it from occurring in the future.
What is Piston Slap?
Piston slap is a knocking noise that can be heard from the engine of a vehicle, typically when it is cold. The noise is caused by the piston rocking back and forth inside the cylinder due to excessive clearance between the piston and the cylinder wall. This excessive clearance can be due to worn bearings or cylinder walls, which would allow the piston to move around more than it should.
How to Identify Piston Slap in Your Subaru?
The easiest way to identify piston slap is to listen for a knocking noise coming from your engine when it is cold. If the noise gets quieter or disappears completely as the engine warms up, it is likely to be piston slap. You can also check the oil pressure gauge or light, as low oil pressure can contribute to the issue.
How Does Piston Slap Affect the Performance of Your Subaru?
Piston slap can affect the performance of a Subaru in several ways. The knocking noise can be irritating and affect the overall driving experience. It can also cause premature wear and tear on the engine components, reducing the lifespan of the engine. If left unaddressed, piston slap can lead to more serious engine problems, such as engine failure.
What Causes Piston Slap?
There are several underlying issues that can cause piston slap in a Subaru, including:
- Worn bearings: If the bearings that hold the crankshaft in place are worn, it can cause excessive movement of the crankshaft and, therefore, the piston.
- Worn cylinder walls: Over time, the cylinder walls can become worn, which can cause the piston to move around more than it should.
- Excessive engine wear: General wear and tear on the engine components can contribute to piston slap.
- Improper engine repairs: Incorrect repairs, such as incorrect bearing installation or using oversized parts, can cause piston slap.
How to Fix Piston Slap in Your Subaru?
The most effective way to fix piston slap in your Subaru is to replace or repair the worn components that are causing the issue. This may involve an engine rebuild or replacing specific engine parts, such as the bearings or cylinder walls. If caught early enough, replacing the engine oil and performing regular engine maintenance can prevent the issue from developing in the future.
How to Prevent Piston Slap in Your Subaru?
Preventing piston slap in your Subaru can be done by performing regular engine maintenance, such as oil changes, and using high-quality engine oil that is suited for your vehicle. Avoiding harsh driving conditions, such as excessive idling, can also help prevent the issue from developing.
Frequently Asked Questions (FAQs)
Q: Is piston slap a common issue in Subaru vehicles?
A: Yes, piston slap can be a common issue in Subaru vehicles, particularly in high mileage or older vehicles.
Q: Can driving with piston slap cause damage to my engine?
A: Yes, driving with piston slap can cause premature wear and tear on your engine components and lead to more serious engine problems if left unaddressed.
Q: Can I fix piston slap myself?
A: While there are DIY methods to fix piston slap, it is best to have a certified mechanic diagnose and repair the issue to ensure it is done correctly.
Piston slap can be a common issue in Subaru vehicles, but with proper diagnosis and repairs, it can be fixed. Regular engine maintenance and avoiding harsh driving conditions can also help prevent the issue from developing in the future. If you suspect piston slap in your vehicle, have it diagnosed by a certified mechanic to avoid more serious engine problems down the line.