Oil Sludge - An Engine's Worst Nightmare

You have probably heard all the bad things surrounding oil sludge. But what exactly is it? Oil sludge is a dense, jelly substance that is formed when engine oil is oxidized and contaminated in a car. It is made up of contaminants and often sticks various engine parts, and inhibits oil flow. 

How Does It Form?

Oil sludge can be found anywhere: on the surface of the engine, inside the oil pan, or a valve cover. Because engine oil goes through high temperatures and pressure, it is susceptible to oxidizing when exposed to air. The molecules in motor oil break down during oxidation and can combine with dirt, fuel, metallic scraps, water, gases, and even coolant. This combination of gunk is sludge and stores heat instead of releasing it, making it more challenging for the cooling system to do its job. 

Sludge can form for various reasons. The most common explanation for oil sludge is frequent drives in heavy traffic. Too many short-distance trips and long periods of stop-and-go traffic can also stimulate oil sludge build-up.

How Harmful Is It?

As mentioned earlier, oil sludge negatively affects the oil flow in your engine. Since oil is liable for cooling and lubricating your engine, weakened circulation will make your engine susceptible to damage. It can also put your motor at a higher chance of overheating. In addition to lower performance, oil sludge will ultimately result in costly repairs.


In summary, oil sludge is your engine's worst nightmare. The good news is that if you regularly examine your oil and check its condition, you can prevent sludge from forming in the first place. If you require an oil service or want to get rid of sludge in your engine, we invite you to Autoworks of Issaquah today!

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