Metal flakes in oil and why they appear
Any observant driver will notice that something is wrong with their car. Many observations are harmless, but sometimes they indicate a bigger problem. If you find shiny metal particles in your oil, this is one of the warning signs.
Learn the underlying causes of microscopic metal shavings and metal flakes suddenly appearing in your car’s oil and what to do if you find yourself in such a situation.
Are metal flakes in oil normal? Almost all vehicle engine oils contain tiny, microscopic metal particles, but these particles are never visible to the naked eye. The only exception to this rule is when these particles adhere to a magnetic drain plug or other polarized objects. But even so, such particles should be rare in nature.
The sudden accumulation of metal particles in your engine’s lubricating oil should never be considered “normal.” On the contrary, this anomaly is often an indication that something is wrong with the engine’s internal components or rotating assemblies.
An exception may be made if the threads on the oil drain plug wear away during an oil change. As a result, even if the drain plug is removed and replaced, and possibly the oil pan is re-threaded, small amounts of metal shavings may remain in the oil drain pan.
What does it mean if I find metal shavings in my oil?
Unfortunately, once one or more bearings in your engine begin to wear out faster, irreparable damage has already been done. This wear pattern usually continues and gets worse over time. In most cases, metal shavings are produced with every subsequent oil change.
How serious is this problem?
The problem with accelerated bearing wear is that it’s a never-ending cycle. As engine main bearings, connecting rod bearings, and camshaft bearings wear, their tolerances increase beyond the manufacturer’s specified values. These tolerances are critical to the operation of the engine because they are directly related to the engine’s ability to maintain proper oil pressure.
Over time, worn bearings can no longer hold pressure as well as new ones, allowing oil to flow through them without resistance. This often results in a noticeable loss of oil pressure.
As a result of this loss of oil pressure, the engine’s bearings are starved of critical lubrication. This exponentially compounds the problem and can cause multiple bearing failures in a short period of time.
In severe cases, a knocking or clicking noise may be heard while the engine is running, which primarily indicates a lack of oil in the upper engine sections as well as bearing failure at a later stage.
Does the oil filter trap metal particles?
Oil filters are good at trapping most of the metal contaminants in engine oil, but they are not foolproof. In general, the oil filter will trap most of the larger metal shavings circulating in the engine. However, many metal particles are too small to be captured by the oil filter.
As a result, these microscopic particles travel further through the engine’s bearings, where they act as a kind of abrasive. Over time, this can further accelerate the wear of the bearings, especially if the engine oil is not changed at the manufacturer’s recommended maintenance intervals.
What to do if you find metal shavings in your engine oil?
If you find metal shavings in your engine oil, it is definitely a cause for concern and should not be taken lightly. In any case, further diagnosis is required.
In most cases, this will require removing the engine’s oil pan and bearing caps to carefully inspect the bearing surfaces for wear. If the surfaces are scratched or show any type of accelerated wear, you have a bigger problem.
Unfortunately, if the bearings in your engine’s rotating assembly wear out quickly, your options are limited. In most cases, you will need to remove the engine and overhaul it. What about metal shavings in gear oil?Unlike your car’s engine oil, transmission fluid is expected to contain metal shavings. This is especially true if your vehicle’s transmission oil hasn’t been changed for a long time.
These visible metal pieces are usually the product of normal gear meshing and probably don’t indicate anything other than normal wear. In fact, most transmission pans contain magnets to trap such deposits. However, be wary of metal shavings large enough to pinch between your fingers or that have sharp edges.