Crush Washers and Drain Plug Washers: Small Parts with a Big Role in Engine Health

When it comes to maintaining your car’s engine, most people focus on oil quality, filters, and service intervals. But there’s one small component that often goes overlooked and can make a significant difference in engine performance and longevity: the drain bolt crush washer. Whether you're using an aluminum drain plug washer, a crush washer M12, or a crush washer M14, this small ring ensures your engine oil stays sealed and secure. In this article, we explore the importance of choosing the right car drain plug washer, how it works, and where you can find quality options—including those from Advance Auto Parts.

What Is a Crush Washer and Why Does It Matter?

A crush washer is a type of sealing washer designed to create a tight seal between the oil drain bolt and the oil pan. Unlike flat washers, crush washers deform slightly when tightened, "crushing" into place to fill any gaps and form a leak-proof seal.

Key Functions of a Crush Washer:

Seals the oil drain plug to prevent leaks

Distributes pressure evenly to avoid damaging the oil pan

Compensates for minor surface imperfections between the drain bolt and oil pan

Protects the bolt threads by providing a cushion during tightening

Even though this washer is small and inexpensive, it plays a big role in your engine’s health. A missing or damaged washer can result in persistent oil leaks, leading to low oil levels, poor lubrication, and eventually, engine damage.

Different Types of Drain Plug Washers: Materials and Sizes

Drain plug washers come in various materials and sizes, and choosing the right one is critical for proper sealing.

Common Materials:

Aluminum Drain Plug Washer: Lightweight, corrosion-resistant, and commonly used in many OEM applications. Aluminum is soft enough to deform and create a seal but durable enough for multiple uses in some cases.

Copper Crush Washer: Known for excellent sealing properties and high heat resistance. Commonly used in European and performance vehicles.

Nylon or Fiber Washers: Typically used in lower-pressure systems or temporary fixes. Not ideal for long-term use with hot oil.

For most modern vehicles, aluminum drain plug washers are the go-to option due to their balance of performance, cost, and availability.

Common Sizes:

Crush Washer M12: Fits M12 (12mm diameter) drain bolts. Often found in smaller cars and motorcycles.

Crush Washer M14: Fits M14 (14mm diameter) drain bolts. A very common size used across a wide range of vehicles.

Using the correct size is crucial. A washer that's too large or too small won’t create a proper seal and could cause leaks.

Where to Find the Right Washer: OEM, Aftermarket, and Auto Parts Stores

Many vehicle owners forget to replace the drain bolt crush washer during an oil change. In fact, some oil change services reuse old washers—leading to gradual oil seepage over time. Thankfully, these washers are inexpensive and widely available.

OEM vs. Aftermarket Washers:

OEM (Original Equipment Manufacturer) washers are designed specifically for your vehicle make and model. They offer guaranteed fit and performance.

Aftermarket options are available in universal sizes like crush washer M12 and M14, and often come in multi-packs for convenience.

Buying from Advance Auto Parts:

Auto parts retailers like Advance Auto Parts carry a wide selection of crush washers. Whether you need a car drain plug washer for a Toyota, Honda, Ford, or BMW, you’ll find compatible parts based on vehicle specifications.

When purchasing from Advance Auto Parts or similar stores:

Look for application guides by vehicle make and model.

Choose the correct material—aluminum or copper for most modern vehicles.

Double-check bolt size before purchasing. Use calipers if unsure whether you need M12 or M14.

How to Replace a Drain Plug Washer: Step-by-Step Guide

Replacing your drain plug crush washer is simple and should be done every time you change your oil. Here’s a quick guide:

What You’ll Need:

New crush washer (correct size and material)

Socket wrench and oil drain pan

Torque wrench (recommended for precise installation)

Drain the Old Oil: Loosen the oil drain bolt and let the oil drain completely into a pan.

Remove the Old Washer: It might stick to the bolt or the pan—be sure to remove it fully.

Install the New Washer: Place the new crush washer onto the bolt before reinstallation.

Tighten the Drain Bolt: Use a torque wrench to tighten the bolt to the manufacturer’s specification—usually between 25–30 lb-ft for most vehicles.

Check for Leaks: After adding new oil and running the engine briefly, inspect the drain plug for any signs of leakage.

Using the wrong washer—or forgetting it entirely—can lead to poor sealing. It’s a small part, but it makes a big difference.

Final Thoughts: Don’t Overlook the Washer During Oil Changes

The drain plug crush washer might be one of the smallest components in your vehicle, but its role in protecting your engine can’t be overstated. Whether you're using an aluminum drain plug washer, a crush washer M12, or M14, always make sure to replace it during every oil change.

Purchasing the correct car drain plug washer is easy through retailers like Advance Auto Parts, which offer a variety of materials and sizes tailored to your vehicle. Remember: skipping this simple step can lead to oil leaks, messy driveways, and even engine damage.

For just a few cents and a few seconds of effort, you can ensure a proper seal—and peace of mind—every time you change your oil.