Assign a 'primary' menu

What Oil Does In My Engine

Published June 7, 2018 in Uncategorized - 0 Comments

Engine oil has been described as the life blood of engine. Similar to the blood in our circulatory system oil circulates throughout the engine to supply a lubrication layer to the mechanical components of an engine. Here is the link to a short video that show just how oil lubricates an engine. How Engine Lubrication System Works.   I covered this in my Blog Post on The Journey of Oil in My Engine

Oil does much more for an engine than lubricate. It provides cooling, cleaning, and a bunch of other chores.  When oil is not present serious degradation and ultimate engine failure will occur. One can find a number of videos on You Tube, where people have driven a car or ran a piece of equipment without oil and recorded the failure results. Here is just one example that though not spectacular highlights how oil functions using an infrared heat sensor. What Happens to an Engine Without Oil

You already know engine function is degraded when you run out of oil. Let’s see if we can run it down to make more sense for you how it happens.

Let’s say, for lack of argument, your engine is running with very little to no oil. The engine oil light is on as the engine is running. Antifreeze is up to snuff, but that won’t stop overheating for too long. Here is what happens:

As whatever limited oil is in the engine is pushed around, it becomes hotter and hotter. It becomes hotter because the oil isn’t allowed enough time to cool down a little before it is required to go back into the engine and do its thing. As this happens, the oil will wear out faster. Fully synthetic oil will last longer than dino (refined) oil, but it will suffer defeat sooner or later as well. Several reactions happen to the oil, to include oxidation, thermal degradation, and compressive heating. Mind you, all of these things are created under normal use conditions (and thus the reason we change oils when we should), but under extreme conditions of low oil, high temperature, high load (towing) or racing, it all happens much faster.

This is a great image which describes what happens from the Machinery Lubrication website




These breakdown of the oil creates the regular: tar; sludge; varnish; soot; etc. All of these things start depositing on the internals of your engine, such as the rings, bearings, cylinder walls … anywhere oil would normally flow. If you go back to your chemistry teachings, you’ll probably remember that a large portion of oil is carbon. All of the previously mentioned nasty substances are actually carbon byproducts. As these carbon substances continue to deposit, any part which comes in contact with them gets wear on them as carbon can become quite hard and/or sticky under the right circumstances. This starts creating more friction on these parts. So now instead of cooling/lubricating/cleaning, the oil has broken down is now heating (due to more friction), creating deposits, and making the engine a really filthy place. You should realize it is now doing everything it was originally meant to replace.


As previously mentioned, this can occur under regular operation and can result in engine degradation or failure if the oil is not changed on a maintenance schedule. To see exactly what this looks like here are the links to a 2 part video produced by Cooper Lake Automotive which describe what happens when you don’t change the oil in your vehicle. They show the work needed to be done to get a 2006 vehicle with a 130K miles on it that had maybe 1 or 2 oil changes.


In the next blog article, I will cover why and what additives are put in motor oil to improve its operating efficiency.

No comments yet

Leave a Reply: