Low Cost Oil & Filter Change Plan at HAC Rockhampton

What does oil colour tell me about my car’s health?

Engine oil colour can change with age, additive degradation, contaminants, and heat, among other factors. Although certain shades of motor oil may help you sniff out possible problems, colour alone should not be used as an excuse to delay an oil change or as a DIY diagnostic tool.

In fact, most carmakers suggest using kilometres, driving conditions, and the oil change intervals in your owner’s manual to tell when to schedule your next oil change.

How to check your engine oil colour and clarity

Checking the colour of your oil doesn’t take very long and doing so also allows you to inspect the oil levels at the same time! When you’re ready to check your engine oil, park your car on flat ground and allow the engine to cool for 10 or 15 minutes. The only tools you’ll need are gloves if you prefer to keep your hands clean, and a rag or paper towel.

With the engine turned off and slightly cooled, pop the hood and locate the oil dipstick — it typically has a plastic orange or red pull-tab. If you’re having trouble locating it or find two dipsticks under the hood instead of one, consult your vehicle’s owner manual to help you pinpoint the right one.

Pull the dipstick out, wipe it clean with a paper towel or rag, and then place it all the way back into its tube. Wait for a moment, then pull it out once more and observe the oil level, colour, and viscosity. After you get a clear reading of your engine’s oil colour, give the dipstick one last wipe, and then make sure to fully insert it back into place.

What colour should my engine oil be?

Typically, brand new engine oil is a slightly translucent amber colour that has the consistency of olive oil. After new oil is added to your motor, it circulates through the engine block, lubricating its moving parts, redistributing heat, cleaning the engine, and helping inhibit rust and corrosion from forming as it goes!

Over time, the oil typically becomes darker and thicker, which makes it less efficient at its core jobs. Oil that can’t perform the way it should may compromise your engine’s health and create wear and oil consumption. These issues can lead to scary symptoms like blue or grey exhaust smoke, reduced fuel efficiency, and shaking while idling!

The colour of clean engine oil: shades of amber

Clean engine oil can appear as different shades of amber, depending on the type of oil in your car and the age of your vehicle. According to Car Buyer Labs, certain additives may cause your oil to become darker faster.

Motor oil also darkens as it absorbs by-products from combustion. Because of this, darker shades of amber by themselves aren’t a sure-fire sign that your engine oil is old or dirty. In fact, oil darkening may indicate it is doing its job well.

What does black engine oil mean?

Engine oil that’s turned from a dark shade of amber to black could be a sign that your oil is old, especially if it is thick or sludgy. In some cases, black engine oil can indicate a clog in the fuel return line, which could allow contaminants into the engine, causing poor engine performance, inefficient fuel mileage, and possibly engine failure.

What does brown or grey engine oil indicate?

If your engine oil turns brown or grey, you may need to do a little more investigating. Brown engine oil shouldn’t be an immediate cause for alarm. However, brown or greyish engine oil with a milky or foamy consistency can be a sign of contamination from a coolant leak or a sign that the engine idles excessively and seldom reaches operating temperature — which tends to happen to cars that are only driven for short periods.

Here’s the problem with short trips. Water is produced as an engine burns fuel. It’s part of the chemical equation. Hopefully, the water travels out of the tailpipe with the exhaust. However, some water can make its way into the engine oil and accumulate if the engine doesn’t reach its optimal operating temperature often enough and for long enough. The optimal temperature is hard to reach on a short trip!

What causes rust-coloured engine oil?

According to the RACQ, motorists who own older vehicles and live in areas with more humid or cooler weather may find themselves with rust-coloured engine oil. Humid conditions can cause condensation build up and surface rust on your metal dipstick, resulting in a rust-coloured reading when checking motor oil. Alternatively, a reddish appearance in the oil might indicate the presence of automatic transmission fluid, which should be diagnosed by an automotive technician.

Check oil frequently to identify irregularities

Colour is not the be-all-end-all indicator of engine oil health. However, it’s important to note colour changes in your engine oil, especially when paired with fluctuations in oil consistency and volume, as they can help clue you into oil-related problems!

At the end of the day, checking your engine oil is a proactive form of DIY car care. But evaluating your engine oil takes more than just looking at it's colour — it takes professional services and maintenance, guided by the recommendations in your owner’s manual. Visit your local Highway Auto Rockhampton for an expert opinion on the state of your motor oil, affordable oil changes, and all things car care.