How Do I Know If My Oil Filter Is Bad? (Symptoms)

Bad oil filter symptoms - thumbnail

A clogged or bad oil filter is detrimental not only to the engine’s performance but also to the entire motorcycle. It’s important to address it as soon as possible.

So, how will you know if your motorcycle oil filter is bad or clogged?

Here are the major symptoms of a clogged oil filter:

  • Oil light or engine light is ON
  • Oil is dirty and dark in color
  • Gray smoke is coming from the exhaust
  • Engine overheating, high vibrations, and noise
  • Oil filter is leaking oil

Let’s discuss each of these symptoms one by one in detail followed by suggested solutions and preventive measures for a clogged oil filter.

Bad oil filter symptoms

Here are the symptoms of a clogged up or damaged oil filter in a motorcycle:

#1. Oil light or engine light is ON

Most modern motorcycles have engine malfunction indicators now.

If the oil filter is clogged up or has gone bad, the engine receives unfiltered dirty oil. Leading to engine problems.

Engine malfunction indicator on motorcycle

In such cases, the engine malfunction light gets ON on the motorcycle dashboard.

That’s one of the major symptoms to the rider that something is wrong.

Even better. Some motorcycles have oil pressure warning lights.

Oil pressure warning light

If the oil light starts to beep, there is something wrong with the oil.

Either the oil level is low. Or the oil is of poor quality.

From there you can trace the problem to the engine filter.

#2. Oil is dirty and dark in color

Oil filters have a bypass valve. If the filter is clogged, the oil flows through the bypass – without being filtered.

The bypass valve ensures that the oil flows to the crankcase even when the oil filter is clogged.

Oil filter - cross section

So, rather than cleaning the engine oil, the oil filter lets the oil pass through.

The dirt and contaminants in the oil do not get filtered.

As a result:

The oil gets dirty. The oil gets blackened. The oil color turns dark.

Drained engine oil

Even if you fill a new engine oil with a bad oil filter, in no time the engine oil quality will degrade so much that you will be forced to change the engine oil again.

To check the quality of the engine oil you can check the color, smell, and stickiness.

Checking motorcycle engine oil level with dipstick

If the oil is black in color, then it is already of poor quality filled with sludge and dirt, and needs to be replaced as early as possible.

For more details, here is our guide on how to check engine oil quality.

#3. Gray smoke is coming from the exhaust

When the oil filter is bad and not working properly, there won’t be any engine oil cleaning.

As a result, the contaminants in oil start to accumulate and even enter the combustion chamber.

Motorcycle with the engine protruded

Once these contaminants enter the combustion chamber, they will eventually mix with fuel and burn and will eventually flow through the exhaust along with exhaust gases.

What this results in is the burnt contaminants will mix up with the exhaust gases and thus, you will start noticing gray exhaust smoke coming out of your motorcycle mufflers.

White smoke coming from a motorcycle exhaust

The gray smoke is nothing but the engine oil mixed with dirt and other contaminants. the contaminants which the oil filter failed to clean.

If left unchecked, over time these burnt contaminants start accumulating on the walls of the exhaust system and will harm the exhaust as well along with the engine components.

#4. Engine overheating, high vibrations, and noise

Engine overheating is mainly caused by low oil levels or poor quality oil rather than directly because of bad oil filters.

However, since clogged oil filters eventually decrease oil quality, engine overheating is an eventual phenomenon caused by bad oil filters.

Motorcycle Engine

The same can be said about vibrations and the noise coming from the engine.

With poor-quality oil coming from the oil filter, the metal-to-metal contact increases between the engine components.

The bad oil filter eventually increases engine vibrations and noise.

On the other hand, if you have a clean and new oil filter fitted on your motorcycle, the oil filter will clean the contaminants in the engine oil – which translates to a better engine lifespan for the motorcycle.

#5. Oil filter is leaking oil

The last and the most straightforward symptom:

The oil leaks from the oil filter.

Oil leaking from motorcycle

In such a case, you don’t even need much diagnosing. You know something is wrong with the oil filter.

The oil leakage from the oil filter points directly to an oil filter problem.

Check the oil filter.

There might be rare cases of overtightening.

But usually, the oil filter has gone bad. There is a gasket leak, the outer case breakage, or straight-up filter damage.

Diagnosis and Solution

Now that you see the symptoms of a bad oil filter on your motorcycle, it’s time to check the filter.

Remove the oil filter from the motorcycle.

Check the outer casing and the gasket first. If they are damaged, throw out the filter.

If not, take the filter out of the casing.

Inspect the filter material.

Motorcycle oil filter - old and used

Is it blackened? Is there too much sludge? Is the filter bent?

If yes, to any of the above, the filter has gone bad.

Motorcycle oil filter - old and filled with sludge

The only solution is – replacing the oil filter.

You cannot just run your motorcycle with a bad or clogged oil filter.

Running your motorcycle with a bad oil filter will harm your motorcycle from the engine to exhaust eventually and you might have to pay a higher cost only because you were too lazy to replace the oil filter.

Preventive measures

Motorcycle oil filter

Here are the measures you can take to maintain the oil filter and prevent it from going bad or getting clogged up:

  • Change the oil filter regularly: Make sure you change your motorcycle oil filter on a regular basis, at least for every 6000 miles of distance traveled.
  • Avoid double gaskets: When replacing the filter, the oil gasket of the old oil filter sticks with the vehicle rather than coming off. Ensure there are no double gaskets while fitting.
  • Change the oil while replacing the filter: Don’t top up the oil when changing the oil filter. A new oil filter deserves new oil.
  • Use high-quality engine oil: The efficiency of the oil filter reduces rapidly as the oil quality degrades. Use good quality oil in your motorcycle.
  • Use the right filter: Use the same OEM oil filter models while changing. Or at least the filter that is very similar to the one that the manufacturer recommends.

How much does it cost to replace a motorcycle oil filter?

A motorcycle oil filter typically costs around $15 to $20. If you are replacing the filter by yourself, that will be the cost. But if you are going to a service shop, changing the oil filter along with the engine oil might cost around $60.

Where is the oil filter in the motorcycle?

The motorcycle oil filter is located mostly in either of the two locations.
1. oil filter is fitted alongside the crankcase, right below the engine block or
2. oil filter is directly fitted without casing at the bottom part of the motorcycle, right below the crankcase.

Do all motorcycles have oil filters?

All motorcycles have oil filters installed in them. In fact, it’s not just all motorcycles, but all cars and all vehicles and locomotives that have an engine or oil usage in them – have oil filters.
So, in short, all motorcycles, as well as all cars, have oil filters fitted in them.

Can you run a motorcycle without an oil filter?

You can run a motorcycle without an oil filter. But, there will be a huge impact on the performance as well as the lifespan of the motorcycle engine and its components.
The engine will see higher wear and tear. And the oil will form deposits and sludge on the components.

Before you go…

Here are a few more oil filter posts for you: