What is your motor oil color trying to tell you?
We’ve all seen a commercial showing golden fresh oil poured out of the container and into the engine. Some would call it caramel colored, while others may say it is something more yellow than brown. Regardless of what color it starts, the end result will be a transition to a dark brown and eventually black. If you change your vehicle’s engine oil based on mileage, could you be spending more money than necessary on maintenance? Your oil color is an indicator of when to change the oil. Learning what to look for is what we’ll discuss moving forward.
Why Does Your Oil Change Color?
Over time you’ll notice that your engine oil changes from golden brown, to dark brown, and eventually black. Oil naturally darkens when heat is applied. One of oil’s main functions is to continually lubricate bearings and moving parts while the engine is running. It is also to absorb the heat the combustion process creates. Your engine typically operates between 180ºF – 220ºF, and then cools when it is turned off. This heat cycle of heating and cooling darkens the oil a small amount every cycle.
Beyond heat, there are other factors that affect your oil with use. Oxidation can also change the color of your oil. Oxidation occurs when oxygen contacts the engine oil and causes a chemical breakdown. It’s a similar process to watch the surface of steel or iron rust. Soot from the combustion process will also cause oil to turn black over time. Soot is primarily associated with diesels. But the current technology of direct-injected engines can produce more soot than the diesels of yesteryear.
How Oil Additives Work with Your Oil Filter
Your oil filter and engine oil have a one-two punch when it comes to keeping your engine clean inside. The engine oil has additives blended in that act as a detergent to keep your engine internals clean. Soot and other combustion particles are absorbed into the engine oil, then routed to the filter for removal. The engine oil filter traps small particles. It keeps them from returning to the engine where they can build up and cause potential blockages and subsequent damage.
What Other Problems Occur with Engine Oil?
Your engine oil turning black may just be the beginning. There are other things that can happen with your engine oil that signal bigger problems that need to be addressed. If you find that your engine oil looks like a silky chocolate milk, you may have coolant mixed into the engine oil. It’s most likely a leaking gasket somewhere in the engine that has allowed the coolant to leak into the engine oil. The mixed oil and coolant will lead to foam bubbles that leave the engine’s metal components unprotected against wear. It will also allow oil sludge to form and accumulate that can clog oil passages and damage the engine.
Does it Have a Smell?
There are times that your oil may smell like fuel. It’s not a common problem in newer vehicles. But as engines age and piston rings wear, you may find your oil looks or feels thin compared to new oil. If there is enough fuel in your engine oil, you can smell it on your fingers or your dipstick. The fuel reduces your engine oil viscosity. It also allows premature engine wear on critical engine components.
One last problem happens if your oil becomes gritty or extremely dirty. Oil filters have a bypass function built in that allows oil to return to your engine without being filtered if the filter is full. Even on extended oil change options, the filter needs to be changed periodically to keep your engine lubricated properly.
How Long Can I Run Engine Oil Before It Hurts Performance?
It’s easy to say that you should change your oil when it turns to a dark brown color but not reached the blackened stage. But could you continue to run oil longer than recommended without hurting engine performance? The complicated answer is ‘maybe’. Your eyes can see the rough color of the oil. However, the true way to get the best picture of how well your oil is performing an oil analysis. You can submit a used oil sample to a testing facility that can determine the current viscosity of your oil and if you should continue using the oil longer. The results can show current wear particle amount, water contamination, fuel dilution, and more. You can order your Oil Analysis Test Kit.
The old “3,000 miles rule” is no longer valid with today’s engines. Today’s synthetic engine oils, such as AMSOIL Signature Series 5W-30 can be used well beyond 3,000 miles between oil changes without risking lubrication or performance. Partnering those with superior AMSOIL EA Filters will keep your oil performing at its best also. If you need help with determining a complete maintenance plan for your vehicle, your local AMSOIL dealer at Buy Great Oil is here to help with a complete package of products and hints to make the job easier.