How to perform an oil flush

Why You Should Perform an Oil Flush on Your Engine

An oil flush is important for several reasons, all of which contribute to the overall health and longevity of a vehicle's engine. Here are some key reasons why an oil flush is considered an essential maintenance procedure:

Removal of Deposits

Over time, contaminants such as dirt, sludge, and varnish can build up within the engine due to the combustion process and normal wear and tear. These deposits can accumulate in critical engine components, such as the oil passages, piston rings, and valve train, hindering proper lubrication and reducing engine efficiency. An oil flush helps to dissolve and remove these deposits, allowing for better oil flow improving engine lubrication.

Prevention of Engine Wear

Accumulated deposits can lead to increased friction between moving parts within the engine, resulting in accelerated wear and tear. This wear can cause premature failure of engine components, leading to costly repairs or even engine replacement. By removing these deposits, an oil flush helps to reduce friction and wear, prolonging the lifespan of the engine and its components.

Improved Lubrication

Clean engine components allow for better circulation and distribution of fresh engine oil, ensuring that critical parts are adequately lubricated and protected against friction and heat. Proper lubrication is essential for maintaining optimal engine performance and preventing premature wear of components.

Enhanced Fuel Efficiency

A clean engine operates more efficiently, as it can more effectively burn fuel and convert energy into motion. By removing deposits and ensuring proper lubrication, an oil flush can help improve fuel efficiency, saving money on fuel costs in the long run.

Performing the Oil Flush

Start by gathering all the necessary materials and tools. An engine oil flush is best performed while doing an oil change.

Tools for the Job

• Oil flush additive for your engine type (petrol or diesel, most flushes do both)
• New oil filter
• Spanner
• Drain Pan

Note that if the sump plug has a seal, they are worth replacing at each oil change. Ensure you have the correct quantity of flush and oil for your engine and that it meets the manufacturers specifications.

Prepare Your Vehicle

Park your car on a level surface, engage the handbrake.

Introduce the Additive

Refer to the instructions on your oil flush additive to determine the correct dosage. Carefully pour the additive into the engine through the oil filler cap.

Idle the Engine

Start your car and let it idle for the recommended duration specified in the product instructions. This allows the additive to circulate and break down any sludge and deposits inside the engine. Do not rev the engine or drive the car. Just let it idle.

Drain the Old Oil

Shut down the engine.  Let the engine cool though do not let it get cold. Drain the oil while it is still warm as it flows better than cold oil.  Locate the oil drain plug underneath your car and use the spanner to loosen it. Have an oil drain pan ready to catch all the old oil. Drain the old oil and flush from the sump. Don't forget to remove the old oil filter using the oil filter tool. Take care handling it as it may be full of hot oil.

Note: Take care during this process as parts of the engine can be hot. Wearing mechanics gloves is a good idea. If it feels too hot, let it cool a little longer.

Replace the Oil Filter

Install a new oil filter securely. Make sure it's tightened properly to prevent any leaks. If it is a metal can type oil filter, a light smear of new oil on the rubber sealing ring helps. 

Refill with Fresh Oil

Replace the sump plug seal and install the sump plug. Start it by hand to avoid cross threading.  Torque to specs. Pour the correct amount of fresh oil into the engine through the oil filler cap.

Idle the Engine

Start your car and let it idle for 5 minutes or so then switch it off. This gets the new oil circulating through the engine.

Check for Leaks

Before wrapping up, inspect around the oil drain plug and oil filter for any signs of leaks. Tighten them if necessary to prevent any oil seepage.

Inspect Oil Level

Use the dipstick to check the oil level. Ensure it falls within the recommended range. If not, add more oil as needed until the level is correct. When checking the oil level, it is important that the car is resting on flat surface. If on a hill or tilted to one side the reading on the dipstick will be incorrect as oil, being a liquid, will run to the lowest part of the sump.