Do Generators Have Filters? (Why + What To Do)

If you have a generator, it is important to conduct proper maintenance. Regular maintenance includes changing the oil and oil filter. There are many types of generators. The two discussed in this article include portable generators and standby generators. 

Standby generators are designed to be stationary. They provide emergency power to buildings and other facilities. Portable generators are designed to move around as needed. Most standby generators will have an oil filter. Let’s look to see when they don’t and what to do.

Dirty Used Oil Filter

Do Portable Generators Have an Oil Filter?

While most portable generators do not have an oil filter, some do. You need to review the owner manual to learn if your generator has one. Typically, larger portable generators have oil filters. If you do not have the owner manual for your specific generator, you can find them online. 

How Do You Check the Oil in a Portable Generator?

All generators should have an oil dipstick to check the engine oil level. Generally speaking, portable generators have a small plastic dipstick. They are often located on the side of the engine. The dipstick has markings indicating the proper oil level. 

To check the oil, follow the steps below: 

  • Before checking the oil, make sure the generator is level.
  • Locate and remove the dipstick.
  • Wipe the oil off of the dipstick with a clean cloth.
  • Take note of any metal shavings or debris in the oil.
  • Replace the dipstick leaving it in the engine momentarily.
  • Pull out the dipstick again and look at the oil level on the dipstick. 
  • Add oil to the engine if the oil level is below the recommended level. 

Do Champion Generators Have Oil Filters?

Smaller portable Champion generators do not have an oil filter. However, larger portable Champion generators and standby models do have filters. Champion has a search function where for owners to find their generator manuals. To do this, owners just need the model number from their generator. 

It is important to review the owner manual for your specific model to determine what filters your generator has. 

Generac Generator Oil Filter

Smaller models may not have an oil filter as with the Champion generators. The larger engines on big portables and standby generators will have a filter. The owner manual for your specific model will provide a maintenance schedule and tell you if your generator has an oil filter. 

If you do not have the owner manual for your specific generator, Generac has them online. The website has a search function that locates owner manuals for each model. 

Why Does a Generator Have an Oil Filter?

Oil filters remove contaminants from the engine oil. Contaminants in the oil can cause damage to the engine. Smaller engines will not have a filter. Small engines use an oil slinger to splash oil onto the engine components.

Engines with an oil slinger do not build up oil pressure and will not have a filter. Larger engines use an oil pump. The oil pump generates pressure forcing the oil through the filter and removing impurities. 

What Type of Filters Do Generators Need?

In addition to oil filters, there are a couple of other filters on your generator. Most generators will have an air filter and a fuel filter. 

The air filter prevents contaminants from entering the engine through the air intake. Fuel filters keep water and sediments out of the fuel system protecting the engine from damage. 

Just as with the oil filter, these filters require regular replacement. The generator owner manual will have a maintenance schedule for filter changes. 

Where is the Oil Filter on a Generator?

Generators with oil filters will have a diagram of all parts in the owner manual. You can also see it on the manufacturer’s website.

Typically, the oil filter is on the lower half of the engine. The oil filter is a round canister that screws onto the engine. 

How Often Do I Need to Change the Filter?

You need to change the oil filter each time you change the oil. While some will only change the oil, not the filter, doing so leaves dirty oil in the engine. 

Not changing the oil filter can cause it to become clogged and ineffective. Changing the filter every time you change the engine oil is best. 

How Often Do You Need to Change the Oil in a Generator?

The answer to this question depends on how often you run the generator. Standby units that only operate in emergencies will not need the oil changed as frequently as regularly-used portable units.

For most standby generators, you should change the oil yearly. If the generator runs consistently, you may need to change the oil more often. Keep track of how many hours your generator is running. The owner manual will recommend changing the oil after a set number of hours. 

For most generators, you need to complete the first oil change after a short period. Changing the oil after the first few hours of use helps to ensure the removal of potential contaminants. 

New engines can have contaminants from their manufacturing process. 

Where Does the Oil Drain From a Generator?

Portable generators have a plug at the bottom of the oil pan. The plug is a small bolt that keeps the oil in the engine. When this plug is removed, the oil will drain out of the hole. 

Larger and standby generators may have a hose that drains the oil. The hose has a clamp on one end that is removed to loosen the hose. Once the hose is loose, it is placed in an oil drain pan to drain the oil. 

How Do You Flush a Generator’s Oil?

To change the oil in a generator, you can follow the steps below:

  • Run the generator for a few minutes to get the oil warmed up. 
  • After the generator is warm, shut off the engine.
  • Remove the spark plug wire to ensure the engine can’t accidentally start.
  • Remove the oil plug and drain the oil into a drain pan. 
  • Once the oil drains, remove the filter and replace it with a new filter.
  • Replace the plug and fill the engine with the recommended new oil.

After changing the oil, the generator needs to be started, and the oil checked after running for a few minutes. 

Will a Generator Work Without a Filter?

A generator designed to have an oil filter will not work without the filter. Removing the oil filter will cause oil to drain from the opening, and the engine will not have proper lubrication. 

Running a generator without a filter will ruin the generator. Without oil, the engine will not be lubricated and will seize. 

The Importance of Generator Oil Filters

Most larger generators have oil filters. Impurities in the oil can cause damage to the engine and shorten the lifespan. 

The filter is a critical part of the lubrication system as it cleans oil impurities. 

You should always review the owner manual for your generator. And follow the maintenance schedule prescribed. Doing this ensures a longer lifespan for your equipment. 


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