Caring for one’s car starts with checking one’s oil regularly and following the recommended oil change intervals. To get a quick insight into one’s car’s health, remember to check the level, consistency, and colour of one’s motor oil as it gives clues to the health of one’s engine, including helping spot potential issues like engine oil contamination and leaks.
Though colour on its own does not indicate oil performance, often a lubricant colour change can be a cause for concern, as it often shows the oil’s composition or chemistry has been changed, but one must first consider the lubricant’s original colour. New lubricants usually have a colour that is related to their viscosity and formula.
Certain additives and dyes can affect the original base stock colour. Contamination is another common reason a lubricant changes colour, with the oil becoming darker if there is lubricant cross-contamination or solid particles from the environment. If the same lubricant is used in several machines and all of them show a progressive change in oil colour, this likely would show natural lubricant ageing.
While some shades of motor oil may help one figure out potential problems, colour alone cannot be used as a DIY diagnostic tool. A gradual darkening of the engine oil is normal and indicates that the engine oil is working as expected by cleaning the engine and carrying the deposits and sludge.
To check the engine’s oil colour, here are some steps one needs to follow:
- Park your car on flat ground and let the engine cool for 10 or 15 minutes. Keep gloves or paper towels or a rag handy. Ensure that these are free of dirt to avoid introducing external contaminants into the oil.
- Next, open the bonnet and locate the oil dipstick, it typically has a plastic orange or red pull tab. If you’re having trouble locating it, consult your vehicle’s manual.
- Once located, pull the dipstick out, wipe it clean with a clean paper towel or rag, and then place it back into its tube without introducing external contaminants. Then pull it out once more and look at the oil level, colour and viscosity.
- Use the below yardsticks to get an idea of the colour of one’s engine oil.
- Clean engine oil can appear in different shades of amber (unless it has been dyed), depending on the type of oil in your car and the age of your vehicle.
- 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.
- Brown or greyish engine oil with a foamy consistency can be a sign of contamination from a coolant leak or a signal that the engine idles excessively and rarely reaches operating temperature.
- Humid conditions can cause condensation buildup and surface rust on your metal dipstick, resulting in a rust-coloured reading when checking motor oil.
- A reddish appearance in the oil might also show automatic transmission fluid though some engine oils could be dyed red too.
