Engine Oil Sludge – Is Caused By Your Engine Oil Breaking Down

Engine Oil Sludge - Is Caused By Your Engine Oil Breaking Down
Engine Oil Sludge - Is Caused By Your Engine Oil Breaking Down

So, engine oil sludge, is actually the thickening and breaking down, of your engine oil.

As a result, it’s increasingly less able to do the hard work, of lubricating and cleaning the engine.

Engine oil sludge, is also caused by, deteriorating piston rings and seals. Meanwhile, allowing partially combusted fuel, to escape into the crankcase.

So, the oil now carries, engine oil sludge through the engine.

But, at some point they will find, somewhere to settle. As a result, restricting or blocking the surrounding oil flow, which causes increased engine wear. That’s why, proper maintenance, is the most important key to the prevention of, engine oil sludge.

Keeping your engine clean and your oil changed, will help your vehicle run great for years.

What Is Sludge Made Of:

  • Unburnt and partially burned fuel.
  • Metal fragments from engine component wear.
  • Dirt and debris, that find a way inside your car’s engine.
Sludge Buildup In Cylinder Head
Sludge Buildup In Cylinder Head

What Can Cause Engine Oil Sludge:

  • Excessive idling and lots of short trips, which prevent the oil from fully cycling.
  • Environmental contaminants in the oil (like dirt and debris).
  • Condensation, which can contaminate the oil, with moisture.
  • Hot spots, which bake clumps and oil, right onto the engine.

So, heat from the engine will quickly cook the deposits solid. And, once a blockage spot is established, new buildup will often settle on top of it. Soon, there are hard layers of grime, which are difficult to remove. Prime targets for various forms of deposits include, the fuel injectors, piston rings and valves.

All of which will interfere with, the engine’s smooth and efficient operation. Also, as the oils lubricating properties are diminished, they are less able to clean the engine’s surfaces.

Engine Oil Sludge In Oil Pan And Pickup Screen
Engine Oil Sludge In Oil Pan And Pickup Screen


There are some signs and symptoms that you can look for:

  • You experience low oil pressure in your car.
  • You hear clicking sounds from the valve tappets.
  • Your oil check light comes on.
  • Draining engine oil becomes slow.
  • There is visible greasy and oily substance, inside the oil filter.

Will Synthetic Oil Stop Sludge

Synthetic oils are at less risk, of temperature damage than conventional oils. For drivers in extremely cold climates, synthetic oil helps your car start more consistently. It also reduces the wear that occurs, once your very cold engine is running.

Synthetic oils also have, a much lower evaporation rate than conventional oils. So, if you do a lot of stop and go driving, the heat inside your engine increases. Synthetic oil provides greater protection against, extreme heat for a longer period of time. Yes, synthetic oil is good, but it’s not a magic cure for oil sludge. Synthetic engine oil, is still oil.

Engine Sludge Buildup Inside Valve Cover
Engine Sludge Buildup Inside Valve Cover

How To Slow Down The Development Of, Engine Oil Sludge

Make sure that you change your oil and oil filter, on a regular basis. Since the development of engine sludge is directly related to, how often you change your oil.

Manufacturers market their oils with specific additives, to customize their products for different cars, varying weather conditions and purposes:

  • High-mileage cars.
  • Stop-and-go commuting.
  • Racing applications.

As a result, these oil additives include, conditioners that lubricate the seals and detergents that help clean. Detergents are there, primarily to prevent deposits. They’ll also inhibit rust and corrosion, inside your car’s engine. Consequently, helping dissolve existing buildup, before it becomes a problem.

Also, dispersants break down build up and suspend the particles in the oil. The end result is, the filter catching the contaminants.

Cylinder Head Covered With Engine Oil Sludge
Cylinder Head Covered With Engine Oil Sludge

Engine Flushing To Remove Sludge

So, the best method of removing engine oil sludge is, frequent oil changes. A good quality engine oil, will have the proper detergents that can, dissolve engine sludge, deposits and varnish.

Note: The use of any aftermarket additives, may or may not help. So, lots of research needs to be done, before using them at your own risk.

The simplest solution here is to use a, chemical engine sludge remover. There are some that don’t really like them, but they are the easiest way, to get rid of sludge. They are typically added to the old oil, then you idle the engine for 5-10 minutes without driving it.

This gives the chemical solution time to, dissolve the sludge and draw it back into the oil. Then you change the oil and the engine sludge, is removed along with the old oil. Finally, be sure to follow the specific application directions, for whatever you are using.


Over time, engine oil breaks down and becomes contaminated with dust, dirt and debris from the engine.

Top reasons oil and filter changes, are so important to a car engines well-being:

  • Maintains engine lubrication.
  • Cools engine components.
  • Removes engine wear particles and engine oil sludge.
  • Improves gas mileage.
  • Promotes vehicle longevity.

Finally, the bottom line is that regular oil changes are the single, most important part of vehicle maintenance.

Thank You !