My Car Has Metal Shavings In Motor Oil – Is It Bad?


Oil is just as important for the engine as blood for humans. It is designed to lubricate the moving parts of the engine to ensure its smooth operation.

When oil becomes contaminated with debris, such as metal shavings, it can no longer function properly.

Performance impact is only a minor change that metal shavings can do to your engine. If untreated it can have catastrophic consequences to your engine.

In this article, we’ve gathered everything you need to know about metal shavings.

How Do Metal Shavings Get Into Oil?

Metal shavings form when two metal engine parts rub against each other. Then the oil flows into the engine, taking the metal shavings with it.

They get in between each moving part and the surrounding surfaces, scarring them up. This often occurs when oil pressure is low for a second, right at start-up.  And that’s how metal shavings get into the oil.

Metal Shaving Types

Iron: You can test if they are iron with a magnet, if that’s the case it can be assumed that they are from rotating parts such as the camshaft, crankshaft, or valve train parts.

Copper/Brass/Bronze: it’s likely a worn bearing or bushing, camshaft bearings, crankshaft, wrist pin bearings, or turbo thrust bearings.

Aluminum: It’s likely from the wear on the surface of the bearing for the overhead camshaft or the aluminum caps holding the camshaft in place.

Chromium/Molybdenum: It’s likely from the wear of pistons and piston rings.

Why Are Metal Shavings Bad?

Metal shavings can form from many different parts, but typically, it’s something to do with a rod or main bearing being “spun”.

This does not necessarily imply that your engine is beyond repair, but the damage is very bad.

In almost every scenario the engine comes out to be completely torn, leaving a very pricy repair 

The crankshaft is milled to a very strict tolerance to fit inside a hole called a journal; the journal is lined with a bearing made from relatively soft metals such as brass and lead.

When the engine is turning the oil pump will send oil into tiny passages into the journal suspending the crankshaft in a very thin film of oil.

The crankshaft will touch the bearing when there is no oil resistance and the friction will take it and it will continue to travel within the journal; this scratches the journal.

Many car shops can not fix this sort of damage because they do not have the equipment to do it because you need to do something called “align honing” to ensure that the center fits the center of all the other journals on which the crankshaft sits as you repair the broken journal.

To sum it up. The oil flows into the engine, taking the metal shavings with it.

Then they get in between each moving part and the surrounding surfaces, scarring them up, making them lock up in several cases.

After that, since it will seal or slip smoothly, the vehicle will never run correctly. The added friction would continually cause the engine to overheat as well.

Repairing this would mean that the entire engine would be totally disassembled and any scarred part replaced.

The labor costs would be astronomical, and only purchasing a new engine would be cheaper.

Will Oil Filters Catch Metal Shavings?

The primary job of an oil filter is to not let debris through, but whether it can catch metal shavings is a different question. it all depends on the size and the type of filter.

Metal shavings come in different sizes, but they’re mostly very thin. Usually, many metal shavings are too small to be caught by any oil filter.

In a paper filter, metal particles that are a few microns in size will go on through. Paper oil filters are meant to catch sludge, which has much bigger particles.

Small metal shavings are not caught by disposable oil filters (with paper filter media). Reusable filters do, only if they have strong magnets.

You can’t rely on a disposable oil filter to filter metal shavings out of motor oil at all times.

Get a lifetime oil filter with solid magnets if you’re concerned about your engine oil being polluted with metal shavings.

Symptoms Of Contaminated Oil

Metal shavings contaminate your oil and can cause lasting effects if you don’t get rid of them. But what are the symptoms of metal shavings in oil?

First of all, there’s no point of figuring EXACTLY what are the symptoms of shavings on oil as it fits in the same category – oil contamination. And that we will gladly answer.

Ticking Noise

During operation, the engine continuously pumps oil throughout the entire block and cylinder head, after a while the oil becomes contaminated and loses its properties.

It becomes thicker, clogs the oil channels, and until the engine warms up, it does not go to all places of the engine to lubricate the moving parts.

A “ticking” or “clattering” sound indicates that oil is not flowing into the cylinder head. This is especially true for vehicles with hydraulic valve lifters.

Rough Idling

Another negative sign of contaminated engine oil is rough idling. if the vibration disappears as the engine warms up, the cause can be in dirty oil.

Dirty oil increases friction between pistons, rings, and bearings, which causes the motor to “shake”.

Decreased Power

Contamination in the engine oil can cause the car to become weak in acceleration. It feels like the engine has been “strangled”.

Old and dirty oil poorly lubricates the moving parts inside the engine and as a result, it does not work at its maximum power and efficiency 

Engine Knocking

Knocking when the engine is running may indicate a lack of oil level or its contamination. Ignoring this sound can lead to wear on bearings, bushings, and crankshaft.

This characteristic knock sounds like a toggle switch. Typically, the engine will jerk at the moment of knocking and the sound will increase as the engine speed increases.

Unfortunately, if you hear the sound of a knock, then a simple oil change will probably not solve the problem, although if you pay attention to the sound at the initial stage, it could be as easy as changing the oil.

White/Gray Smoke From Exhaust

Chromium and molybdenum are metals used in pistons and piston rings.

When pistons and piston rings wear, breakage occurs, making the exhaust emit white or grey smoke behind while using excessive amounts of oil.

Oil Pressure Light

If the engine oil pressure light is on, it means that the oil pressure in the system is very low. This warning cannot be ignored. 

In this case, you should stop and check the oil level. If the oil level is normal, the sensor is most likely faulty.

If the oil level is less than necessary, you should fill up the oil level and try to start the car again. If the light goes out, you can continue driving.

But in any case, a visit to the mechanic should not be avoided.

Read: Oil Light in Car: What To Do and How To Fix?

Other Signs

Most cars are pretty smart nowadays. Filled with computers and sensors, it could detect if your oil is contaminated. Here’s what you need to look for:

  • “Check Engine” Light
  • Service Engine Soon
  • Oil Pressure Light
  • Etc.


As you can probably tell by now, having metal shavings in your car is not a good sign, and by the time you even realize it’s a problem, it might not even be worth to fix it.

If you don’t want that scenario then make sure to have a good oil filter and routinely change your oil. Take good care of your car.

Leave a Comment