What Causes Metal Shavings in Oil?

by Synthetic Oil | Last Updated: August 13, 2022

When maintaining your vehicle, you may see things that you didn’t anticipate. Dirt and leaves and sometimes even remnants of a mouse’s nest are common. But what about small metal shavings in the motor oil? You may be immediately alarmed by the sight. Metal shavings are not normal and need to be investigated. The quicker you act, the faster you can solve the problem. For that, you are going to need to know what causes metal shavings in oil.

Let’s get started.

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What is a Metal Shaving?

For the sake of comprehension, let us first define metal shavings and flakes. Metal shaving refers to a tiny chip, flake, or piece of metal that is sometimes the result of wear and tear or contamination. Metal shavings often stick to the drain plug, crankcase, dipstick, and oil filter, but you may also see them at the bottom of the barrel used to change your oil.

The kind of metal shavings you see may also point to various issues, including:

• Aluminum: points to wear and tear on engine surfaces
• Iron: points to issues with the camshaft, crankshaft, or valve train sections
• Copper, bronze, or brass: indicates damage to the engine bearings and bushings

Don’t worry if you cannot tell one piece of metal apart from the others. As long as you know any issue related to metal shavings is serious, you can start working towards a solution.

Is it Normal to Have Metal Shavings in Oil?

The engine is made of many metal components, and many can grind together or wear down over time. During these moments, small, nearly invisible metal pieces are shed. Rarely do they cause problems. However, if you see these metal particles sticking to the drain plug or any other magnetized object, it could cause those particles to stick to the engine.

If you spot metal shavings in the oil filter or in the oil after an oil change, do not consider it normal. Oil full of metal shavings is a huge problem. Something is wrong, and you are going to need to fix it to prevent a disaster from occurring.

What Do Metal Shavings Indicate?

As mentioned above, when you spot metal shavings in oil, it often means damage or degradation of some kind. Metal wears down, and the shavings start to collect in the engine’s oil as it sweeps through and cleans away sludge and other debris. This is one of the reasons why oil changes are so important. Unfortunately, when these components are wearing down at an accelerated rate, it can cause bigger pieces of metal to fall off, making the shavings far more visible.

Sources of Metal Flakes in Oil

Motor oil has many functions, and in order to do its job, it passes through many moving parts of the engine. Given the speed at which these moving pieces function, it makes sense that there would be some wear. The oil filter is designed to pick up the contaminants that the oil gathers on the way through the engine. Yet, the oil filter is not perfect. It can’t catch all the metal shavings present.

Using an oil filter magnet will significantly help.

The parts that have the most influence on metal shavings in the oil are the bearings. Engine bearings, which consist of main, small-end, connecting rods, and camshaft bearings, are often made with two or three metals. The bearings usually have a surface of brass, aluminum, or copper—all low-friction—and are backed with resilient steel for more longevity.

An auto technician can use the metal shavings to determine the true source of metal shavings in oil. They may also check to see if the metal is magnetic or not. Non-magnetic particles will tell a technician that the bearings are failing. If the metal is magnetic, then they may end up checking the crankshaft or other engine components for issues.

Signs of Metal Shavings in Oil

Most people have a decent understanding of their vehicle and how it handles when they are behind the wheel. Should you notice something amiss, it is best to get the problem diagnosed immediately. You could potentially evade hundreds or thousands of dollars in repairs if you find an issue before it gets more severe. Metal shavings in oil are one of those problems you should not ignore.

Here are some signs that your engine oil contains metal shavings:

• Ticking noises. When there is a large buildup of metal shavings in oil, it will start to block the flow of the oil through the engine. This can result in less than ideal lubrication, which causes a ticking sound, even while the car is idling.
• Reduced engine output. How does your car feel when you step on the gas? Does it hesitate to accelerate? If you notice a struggle, it could mean that there are metal shavings contaminating the oil or congesting the filter.
• Engine knocking. Any debris will start to negatively impact the vulnerable parts of the engine. You will hear knocking noises when oil is burning unevenly on the engine cylinders because the burning fuel is feeding on air.
• Rough idling. Poor lubrication—of a lack of it—will result in friction. The parts making rough contact with one another will cause vibrating and shaking elsewhere in the vehicle, especially when you are idling.
• White exhaust fumes. This is always a cause for concern, and the issues can be hard to pinpoint until you get under the hood. If you see white exhaust, it could be a sign of oil getting inside the combustion chamber, past the cylinders. If you see this, go to the repair shop as soon as you can!

Metal shavings in oil can cause many other issues, some of them dealing with oil pressure. In many modern vehicles, a sudden drop in oil pressure or issues dealing with the oil will cause the check engine light to switch on.

In short, keep your eyes, ears, and nose active while driving. Your senses will help you figure out what needs to be repaired.

Potential Problems Caused by Metal Shavings in Oil

Metal shavings may not be as problematic as cracks and leaks within the engine, but they are nefarious. As the metal shavings travel through the engine, they pass between bearings and crankshaft journals and through the oil filter. Along this journey, those shavings might scratch, gouge, and puncture various parts of the engine.

Metal shavings can also congest oil passages, preventing oil from doing what it is meant to do. If the oil passages remain restricted for too long, your car could experience premature engine failure.

Yes, there is always some metal in the engine and the oil, but if you see loads of metal shavings, nothing good will come from it.

What Should I Do If I See Metal Shavings in Oil?

Prevention is key to stopping issues like metal shavings getting into the engine oil. Remember, metal shavings are a sign that there is a lot of friction occurring between internal engine pieces. The best method for keeping the number of metal shavings reasonable is to change your oil regularly. These days, you do not have to change out synthetic oil every 3,500 miles. It is more like 5,000-7,500 miles or more, depending on the quality of the oil.

If you have recently bought a used car from a dealership, consider swapping out the oil filter and oil as soon as you can. Then changing the oil after 1,500 miles to check for any metal shavings in the oil. Should everything look okay, you can start doing the oil every 5,000 miles.

Otherwise, if the metal shavings happen suddenly, be your vehicle new or old, you will need to see a mechanic. Driving around with an excess of metal flakes is a poor choice. You could inadvertently cause irreparable damage to the engine. Even those damages that are fixable will cost you a lot of money.

Is It Normal to See Metallic Shavings in Oil After an Engine Rebuild?

Yes, if you have rebuilt an engine, you can expect there to be metallic flakes in the oil. Your mechanic will recommend changing out the oil and the oil filter within 2-3 weeks of the rebuild.

After that, there should be no metal shavings. If you continue to see them, something is wrong. Try a second oil and oil filter change before calling the mechanic for assistance.

Wrapping Up

Metal shavings in oil may not seem like a big deal, but you should not underestimate the damages metallic flakes can cause. If you fail to handle the issue in a timely manner, the damages to the internal engine are nothing short of catastrophic. Whether you decide to solve the problem with DIY solutions or to take your car to an auto repair shop, metal shavings cannot be left alone. Afterward, routine maintenance will keep the shavings in check.