Is Subaru piston slap bad?

Is Subaru Piston Slap Bad?
Subaru piston slap refers to the noise produced when the piston moves within the cylinder bore and makes contact with the cylinder wall. It is often described as a tapping or knocking sound and is more prevalent in Subaru boxer engines due to their design. Piston slap is generally considered to be a nuisance rather than a serious concern for automobile owners.
The symptoms of piston slap include a tapping or knocking noise, particularly during cold starts, which diminishes as the engine warms up. It is important to note that piston slap is not typically fatal to the engine, but it is not ideal either. Subaru had a significant issue with piston slap in the past, and their fix involved using slightly oversized pistons to address the problem.
In terms of the repair, there are conflicting opinions on whether fixing piston slap is effective. Some individuals have reported that the repair works and eliminates the piston slap, while others have mentioned that the noise returns after some time. It’s important to consider the specific circumstances of the repair and the expertise of the technician performing the work. The repair typically involves replacing the affected pistons, and in some cases, slight modifications to the pistons may be necessary to equalize them.
Ultimately, while piston slap can be an annoyance, it is not generally considered to be a serious issue that significantly impacts the longevity of the engine. However, it’s always advisable to consult with a qualified mechanic or Subaru specialist to assess the specific situation and determine the best course of action.
If you have any further questions or need additional information, feel free to ask!

How much damage can a slap do?

A hard enough slap will jar the brain inside the skull, causing it to impact the skull and transfer a lot of energy to it. This in turn will damage the cells quite severely and has a high chance of leading to death.

Is it okay to drive with piston slap?

Providing it is piston slap and not a cracked piston it is OK. A thicker oil might help.

What happens if you don’t fix piston slap?

It can lead to the engine oil burning which is caused by excessive wear between the piston skirt & cylinder walls because oil will eventually make its way past the piston rings then into the combustion chamber.

Will piston slap hurt an engine?

Piston slap won’t hurt your compression itself. The piston slap can be caused by a number of things. One being a long stroke witch moves the pin up farther in the piston and caused more sideload on the skirts of the piston causing them to wear excessivly or the bore to wear excessively or a combination of both etc…

Should power slap be banned?

The risk of brain trauma, and subsequent long-term damage or death, is higher in power slapping events, compared to other combat sports, she said. “The issue with power slap is they’re told to stand still, so there’s nothing that the person being slapped can do to protect themselves,” Peek said.

Will thicker oil stop piston slap?

Likely it will shorten the period of piston slap. If piston slap is there hot then a thicker oil is unlikely to help much.

Does piston slap go away when engine warms up?

An engine will run with quite bad piston slap for a long time. Generally, it will be worst when the engine is cold, and quieten down as it warms up. A thicker oil may help slightly, but creates other issues so is not really a great idea.

Is it bad to have a piston slap on startup?

This doesn’t necessarily mean the pistons are worn, because some new engines will slap a bit when first started. But if the slap doesn’t go away as the engine warms up, it usually means the pistons and/or cylinders are worn.

Does piston slap cause damage?

Well, the downsides of piston slap are: Bore wear; Friction; Which, in turn causes some additional heat and power loss.

Is piston slap harmless?

As we’ve discussed in the past, piston slap is usually more of an annoyance rather than an issue compromising engine performance or durability.