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

Motorcycle oil filter - old and filled with sludge

A clogged or a bad oil filter can be detrimental not only to the engine’s performance but also to the entire motorcycle. It is 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:

  • Black smoke coming from the exhaust
  • Increased engine vibrations and noise
  • Rapid decreasing of oil quality
  • Poor engine performance and low mileage
  • Engine overheating

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

#1: Black Smoke Coming From Exhaust

When the oil filter is bad and not working properly, there won’t be any cleaning of contaminants from the engine oil. As a result, these contaminants start to accumulate and even enter the combustion chamber.

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 black exhaust smoke coming out of your motorcycle mufflers.

The black smoke is nothing but the dirt and other contaminants from the engine oil which the oil filter failed to clean.

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

#2: Increased Engine Vibrations And Noise

A clogged oil filter sometimes will send oil full of sludge to the engine crank case. Not to mention, there will be metal contaminants as well in the oil.

Bot these combined will hinder the engine performance by not lubricating the engine components properly. This results in increased metal to metal contact of the engine components along with sludge and metal particles adding to the friction between the metal components without much lubrication.

This increased friction between the engine components causes increased noise and vibration in the engine.

However, this is just a small part of the larger problem. If left unchecked, the metal friction can eventually lead to high wear and tear of the engine parts and even engine sputtering and seizure.

#3: Rapid Decreasing of Oil Quality

Even if you fill a new engine oil with a bad oil filter, the quality of this new oil will decrease at a rapid rate. In no time the engine oil quality will be degraded 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.

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.

If the oil has a burnt smell, then the oil is not right for the motorcycle. The oil has been burnt or the oil filter has degraded to a far lower quality for the engine. Either way, you need to change the engine oil.

And lastly, if you feel the oil is sticky and a small line of oil is forming between your thumb and the forefinger when you check its stickiness, then the oil has lost its desired viscosity and lubricating properties. You must change the oil again.

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

#4: Poor Engine Performance and Low Mileage

All these poor oil filter working will lead to poor oil condition, which in turn results in poor engine performance.

The clogged oil filter will eventually result in poor performance for the motorcycle. Poor performance coupled with normal combustion of fuel levels will also result in low mileage for your motorcycle. The fuel efficiency will lower drastically all because the oil filter is in bad working condition or clogged.

Again, the magnitude of poor performance is directly proportional to how long you leave the clogged or bad oil filter unattended in your motorcycle. The longer you leave the oil filter like that, the worsen the engine performance and mileage will be.

Plus, this poor performance compounds overtime until and unless you get your ass up and replace the bad oil filter either by yourself or through the service center. I have seen numerous bike riders who change the engine oil religiously at set intervals and yet, completely ignore oil filters.

#5: Engine Overheating

Engine overheating is mainly caused by low oil levels or poor quality oil rather than directly because of bad oil filters. But since clogged oil filters will eventually decrease oil levels and oil quality, engine overheating is an eventual phenomenon caused by bad oil filters.

An overheating engine is detrimental to both the engine parts as well as a motorcycle in general. While the specific causes for engine overheating may vary, a clogged oil filter is one of the definite culprits having a hand in overheating your engine.

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

Solution and Preventive Measures

The solution for a clogged oil filter is simple and straightforward. The oil filter needs to be replaced. 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.

In a similar vein, to prevent a clogged oil filter, make sure you change your motorcycle oil filter on a regular basis, at least for every 6000 miles of distance traveled.

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.