Engine oil is a slightly translucent, amber substance. A darker shade accompanied by small particles could mean that it’s contaminated. But what does it mean when the oil appears milky?
What Does A Milky Engine Oil Indicate?
Milky engine oil could mean that water has infiltrated the engine chamber. A certain amount of condensation in the oil cap is acceptable and shouldn’t be a problem because it might have been caused by changing weather conditions.
Milky residue on the oil cap could also mean that the vehicle hasn’t been driven for quite some time. Fortunately, under this circumstance, a long drive is enough to burn the water vapors and keep the vehicle running as it should.
However, if you see milky oil on the dipstick, it could mean that the engine oil has been mixed with water and should be flushed out immediately.
Small milky deposits on the oil filler cap can be due to a clogged PCV system. A gasoline engine creates a gallon of water for every gallon of fuel burned (note the steam from the tailpipe on cold mornings), and some of that water will make its way into the crankcase as blowby from the piston rings. Even new engines have a certain amount of blowby.
The PCV system is supposed to pull filter air through the crankcase to remove that moisture/steam by pulling it through the intake manifold where it is eliminated during combustion. If that moisture isn’t purged out by the PCV system, it begins to mix with the engine oil and can cause milky deposits that eventually become dark and ugly sludge, which can clog the oil pump screen and destroy the engine.
What Causes Water or Coolant to Mix with Engine Oil?
Driving in flooded areas can cause water to make its way to the engine chamber. Gasket leaks and contaminated filters can also cause the same problem.
How to Deal With Milky Engine Oil
Don’t start your car once you’ve confirmed that the engine oil has been contaminated with water or coolant. These substances could have messed up the oil’s lubricating properties, which could mean trouble for your engine.
Instead, get an oil change as soon as possible. You might need to flush the contaminated oil multiple times to ensure that the engine is free of water or coolant.
Dangers of Driving with Contaminated Engine Oil
Motor oil is the lifeblood of any engine, and failure to get an oil change can result in a series of problems for your daily driver. Here are some of the most common ones.
Loud Engine Noises and Engine Damage
Contaminated oil won’t be able to keep engine components lubricated, causing them to grind against each other loudly. You might also hear banging or rumbling noises because of dirty oil circulating the engine.
As sludge forms, engine heat tends to melt the sludge and gravity will carry it to the engine oil pan where it can clog the oil pump pickup screen. This process always accelerates engine wear and can even destroy the engine without warning.
Excessive Smoke from the Exhaust
Increased harmful exhaust emissions can also be a result of contaminated engine oil because it can affect the fuel injectors’ flow pattern.
Oil Change Basics: Here’s What You Should Know
Getting an oil change is one of the simpler tasks when maintaining your daily driver’s performance. Here are some things you might want to keep in mind.
Oil Change Interval
Oil change intervals are usually indicated in the owner’s manual. But in most cases, manufacturers recommend getting an oil change anywhere between 7,500 to 12,000 miles or every six months.
There are, however, some exceptions to this rule. A vehicle might need to get an oil change after a shorter interval if any of the following operating conditions exist:
- Driving in dusty areas
- Frequent towing
- Operating below freezing temperatures
- Operating with extended idling periods
Oil Brand Compatibility
According to the Society of Automotive Engineers (SAE), any engine oil can be used regardless of the brand as long as it meets the viscosity ratings set by the vehicle manufacturer.
There are, however, some drivers that prefer a certain brand over another, claiming that it performs the best among other variants. But following the SAE standards, you can rest assured that any brand is safe to use when getting an oil change.
SAE and API Ratings
The SAE and American Petroleum Institute (API) ratings are the only indicators that the motor oil is safe to use in an engine.
The SAE rating refers to the grade number or viscosity range into which the oil fits.
Meanwhile, the API rating on the container, which is represented by a doughnut symbol, signifies that the oil has been tested in automotive engines.
Engine Oil Type
There are generally four types of engine oil一conventional, synthetic, synthetic blend, and high-mileage.
Conventional Motor Oil
Conventional motor oil is the most common type of engine oil. It’s refined crude oil designed for light-duty, late-model vehicles.
Synthetic Motor Oil
Synthetic motor oil is the most expensive type because it undergoes more refining processes than the others. It also contains several additives that help prolong the engine’s lifespan and reduce maintenance costs.
Synthetic Blend Motor Oil
Synthetic blend motor oil is an alternative for those who want to enjoy some benefits of synthetic motor oil without having to pay the full price for it. This type also comes with a higher grade than conventional oil.
High-Mileage Motor Oil
High-mileage motor oil is designed for vehicles that have over 75,000 miles on their odometer. In most cases, this type of oil has a higher viscosity rating and lacks friction-reducing additives.
High-mileage motor oil also contains esters, which help swell oil seals.
The Bottomline
Unusual color and consistency of engine oil is a cause for concern, especially when it appears to be milky. Once this happens, be sure to bring your vehicle to the nearest repair shop to get an oil change before taking it out on the road.
Failure to get an oil change can lead to several problems, including poor engine performance and fuel economy, as well as performance issues, so it’s a good idea to check your vehicle’s engine oil regularly.
Lastly, getting an oil change is one of the simplest yet most important maintenance tasks you’ll need to keep up with to ensure that your vehicle is working as it should. Make sure to stick to the recommended intervals set by the vehicle manufacturer, and know the appropriate oil viscosity before heading to the shop.
Replacing Damaged Engine Components Caused By Milky Engine Oil
Driving with milky engine oil can cause complex and costly problems for your vehicle down the road. Because of this, it’s important to get an oil change as soon as possible.
Fortunately, you can easily get your hands on a new oil filter and engine oil with the help of CarParts.com.
You won’t even have to take one step outside your door to get the things you need for an oil change. Simply visit our website or download our mobile app to shop from the comfort of your home.
Use our vehicle selector to check for compatible parts, and toggle our search filters to shop according to your preferred brand or price range. Placing your order online takes just a few clicks.
We make it a point to get our auto parts from some of the most trusted manufacturers in the industry. On top of that, our warehouses are strategically located all over the US, meaning any of your orders will reach you in just a few days.
Get yourself engine parts that are built to withstand the test of time by browsing our collection at CarParts.com.
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