Car Engine

How To Tell If Your Engine Has Sludge?

Mike Cross
Updated May 19, 2021
How To Tell If Your Engine Has Sludge

Perhaps the dreaded check engine light has come on. Maybe your car just seems “off” or less responsive. It is possible that your low oil light has come on. Your vehicle may be having an issue with engine sludge. It is crucial that you identify and take steps to correct this before it becomes an even bigger problem. You should also know that all vehicles, no matter what make, model, or year, can develop engine sludge.

How To Tell If Your Engine Has Sludge
How To Tell If Your Engine Has Sludge

What is engine sludge?

Engine sludge will develop both on or around your vehicle’s motor. This happens when the oil starts to break down and remains around the engine. Once this sludge is present, the oil is not able to properly lubricate the moving parts of your car’s engine.

What causes engine sludge?

There are a couple of reasons why your vehicle might develop engine sludge. If you tend to drive your vehicle short distances only, this can be a factor. Another cause of engine sludge is driving in stop and go traffic.

Sludge is also caused by the breakdown of oil, this is why mechanics recommend you use a good, quality motor oil in your vehicle. If you go longer than the recommended time for an oil change, this too can contribute to engine sludge.

Engine sludge is made up from the oxidized motor oil, dirt, soot, water vapor, and leaked coolant. Using a good motor oil helps to keep these things suspended in the oil, which then gets flushed out with your next oil change.

How to check for engine sludge?

It is simple to check for engine sludge by yourself. There are a few steps you can take.

  1. Start your car up. Look to see if your check engine light has come on. Another sign would be if your change oil light comes on as well.
  2. Turn your car off. Look for any signs of oil splatter on the outside of your car.
  3. Open the hood of your vehicle. Examine your engine’s oil pan. The oil pan should appear to be clean and the sides should still show some metallic color. If you do not see this, or you see thick, dark, gel-like substance, you have sludge.

What does engine sludge look like?

Engine sludge will look like thicker than normal oil and it will seem to be in clumps. It is also possible that you might notice other debris that has become trapped in the sludge as well.

How can you get rid of engine sludge?

If you have determined that you do have engine sludge, it needs to be removed from your engine quickly. Engine oil can cause your car to have major problems that can be expensive to fix.

You can try and flush the sludge out by yourself at home. You will need a few things to get started.

  1. Engine flush or engine oil flush treatment
  2. New motor oil
  3. Container to collect the dirty oil in
  4. A new oil filter
  5. Wrench for oil filter
  6. Pressurized air
Checking oil level
Checking oil level

Once you have these items, you are ready to begin cleaning out the engine sludge.

  1. Make sure you are parked on level ground
  2. Open the hood and remove the oil cap
  3. Pour the bottle of engine flush or treatment into the engine. Replace oil cap
  4. Start your vehicle and let it idle for about 15 minutes.
  5. Turn off the car and get ready to drain the oil. Hopefully the treatment has had a chance to mix with the sludge so you can flush them out together.
  6. Remove the drain plug from the oil pan and let the dirty oil and sludge drain into your container.
  7. You can also use your air compressor if you want, to help make sure that all the sludge and debris have been removed.
  8. Remove the oil filter and let the oil drain out from there too.
  9. Replace it with a new oil filter. Use a tiny bit of new, clean oil to rub around the oil filter gasket to ensure an airtight seal.
  10. Use your hands to install the new filter. Be sure to turn the filter in a clockwise direction to tighten it.
  11. Put the oil drain plug back in and begin to fill with clean oil. Use the dipstick to check the levels and replace the oil cap when it is filled properly.

If you are not comfortable doing this by yourself, take your car to your local mechanic to do it as soon as possible.

How can I prevent engine sludge from happening again?

Now that you have cleaned the sludge from your engine and replaced it with new, clean oil you want to be sure this does not happen again. Having sludge in your engine can cause problems that are expensive to fix and will impact your car negatively.

One of the easiest things you can do to help prevent the sludge from happening again is to make sure you get regular oil changes. You also want to be sure you have your vehicle serviced according to the manufacturer’s recommendations.

Another way to help prevent sludge is to use the best quality motor oil for your car. Your dealer or owner’s manual will have suggestions for you.  And you should always change the oil filter when changing your oil.

You also want to be mindful of how you drive your vehicle. Stop and go traffic is a contributing factor to engine oil sludge developing. And if you drive your car under extreme conditions, this will also cause sludge to develop. If you do drive your car under these conditions, then be sure to schedule regular maintenance with your mechanic and have the oil changed more frequently.


Owning a car requires you to be mindful of routine maintenance.  Part of that schedule includes regularly changing your oil and the oil filter. Although it may seem to be a pain, it will go a long way towards preventing engine oil sludge from developing and the problems that often go with it.

Mike Cross
Life is too short to drive with stock audio

Leave a Reply

Your email address will not be published. Required fields are marked *

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram