What the Color of Your Engine Oil Tells You
We have a task for you.
Go to your car, pop the hood, and pull out your oil dipstick. Is the oil still good? Do you need to replace anything under the hood? Is anything leaking into the oil? The color of the oil will tell you.
Take a look at three of the most common oil colors you’d find on your dipstick and learn what each color means.
Amber motor oil = good. Photo credit: Dvortygirl
Good news: you have nothing to worry about. Clean oil is amber in color, so if you’re seeing amber on your dipstick, your oil is good for the remainder of whatever interval your vehicle manufacturer recommends.
Still, it's wise to check your oil on a regular basis. It's a smart way to keep an eye on your vehicle.
Dark Brown or Black
Dark brown or black motor oil = maybe good, maybe bad. Photo credit: Dvortygirl
This could mean one of two things:
- The oil is fine and you have nothing to worry about.
- The oil is contaminated and needs to be changed.
So how do you differentiate between the two? Check the thickness of the oil.
If the oil’s still thin and runny, it’s likely fine. Some additives darken oil without affecting its quality. If you check the oil immediately after a long trip and it's brown or black, it’s possible that the oil is actually amber but was darkened by high heat.
If the oil is thicker than usual and clings to the dipstick, that usually means contamination. Either your car’s way overdue for an oil change or your car was recently exposed to a lot of dirt, dust, and grime. Whatever the cause, it’s time for an oil change.
Cream-colored motor oil = bad. Photo credit: Scott
Milky, frothy cream-colored motor oil is always bad news. A broken head gasket leaking coolant into the oil is usually the culprit, and fixing the problem is going to require quite a bit of work. Typically, vehicles with this problem will also leave a trail of white smoke wherever they go.
If you notice cream-colored oil, call your local repair shop and ask them about getting your vehicle in for a diagnosis ASAP. In the meantime, keep a close eye on your vehicle's temperature gauge...if the engine gets hot, pull over the vehicle and let it cool down.
NOTE: There's a chance that cream-colored oil is not evidence of a head gasket failure. Oil that's contaminated with water will look cream colored, and if the source of the contamination is incidental, an oil change might be all you need.
How to Read an Oil Dipstick Like a Pro
Keep in mind that the above guide is not definite. Not all cars are created equal. Also, there are outside factors, such as weather, that can affect the color of your oil. You can still do an accurate reading, though.
The key to an accurate reading is to continually observe the oil in your car. Take a few seconds a couple times a week to check the oil. Soon enough, you’ll see how quickly your oil changes color over time. For some cars, dark brown oil is still good. For other cars, dark brown oil means that the car is overdue for an oil change.
Check the owner’s manual and see when your oil is supposed to be changed, and make a mental note of the oil color at that point. For example, if you have to change your oil every 5,000 miles, note what color the oil is at the 5,000 mark.
The more you know your car and its oil, the more accurate your reading can be.