A few days ago, I too pondered, “does engine oil absorb moisture?” as I thought about the damp weather conditions and my car’s maintenance.

Well, as it turns out, engine oil does absorb moisture, playing a crucial role in destroying lubricant oil and machinery. But how does this exactly happen? There are many answers.

Along with all the different situations where water can access the engine’s oil, this article will help you find ways to prevent it from happening. Let’s begin.

How Does Water Get Into Engine Oil?

There are numerous reasons engine oil mixes with water, causing wear-and-tear of the engine.  This mixture’s most common causes include a blown head gasket, damaged cylinder head, or cracked oil cooler.

Since engine oil’s purpose is to lubricate parts of the vehicle, water contamination reduces friction, causing it to overheat. On the other hand, coolant flows through automotive components, eliminating heat.

Blown Head Gasket

Faulty head gasket is the most common cause that helps water to get into the engine oil. A Head gasket forms an airtight seal to ensure that grease doesn’t leak out.

When the engine stays overheated for long periods, it destroys the Head Gasket. Faulty head gasket supports oil leakage resulting in severe engine damage.

Damaged Cylinder Head

Engine’s overheating results in cracks in the cylinder head. These cracks allow the oil to leak out and mix with coolant. Fixing a damaged cylinder head is complicated, so we recommend you change it.

Tip: if you want to cut costs, replace the damaged cylinder head with a used one.

Cracked Oil Cooler

Again, a cracked oil cooler is one of the most common causes of engine oil and water mixing. The cracked oil cooler is comparatively easy and cheaper to replace.

What Happens When Engine Oil Mixes with Water?

It is a frequently asked question. Engine coolant and oil are two essential liquids of a vehicle.

While engine oil lubricates the vehicle’s parts, coolant makes sure they stay cool, causing no damage to the vehicle’s engine. The issue arises when both of these essential liquids mix.

Symptoms that Engine Oil Contains Water

Does your vehicle’s engine oil look milky? Or does the vehicle’s coolant smell nauseatingly sweet? Well, in that case, we have bad news for you.

The symptoms mentioned above ensure that either your engine oil contains coolant or coolant contains the engine oil. This mixture eventually results in terrible car health, and in the worst possible scene, it can cost you up to $1,000.

How to Detect if Engine Oil Contains Water?

As an experienced driver, it is not difficult for you to find out that your vehicle is not doing well. Here is how to detect leakage while driving:

  1. Brown liquid on the dipstick is the first indication of internal or external leakage.
  2. If engine oil and coolant mix, none of these liquids will be able to perform well. The engine won’t cool or lubricate. Soon, your vehicle will overheat and wear the motor.

To make sure that doesn’t happen, keep an eye on the temperature gauge and take immediate action when the car overheats.

  • Large smoke clouds will likely emerge from the exhaust due to a destroyed head gasket or cracked cylinder. It is time to check for engine oil too.
  • If your vehicle’s coolant continues to lessen, but it doesn’t drop on the ground, it will probably go into the engine oil.

Keep monitoring your car’s condition to timely detect when coolant contaminated engine oil. This way, you can get it repaired soon, preventing engine wear and tear.

How to Test if Engine Oil Contains Moisture?

When you see your vehicle overheating or thick smoke emerging from your vehicle’s exhaust, it is time to go for an engine oil test. There are several procedures you can use to check moisture in engine oil.

Visual Crackle Test checks for moisture level, the limitation for moisture level is up to 500ppm. However, it only checks for free and emulsive water. A drop of oil is dropped on a hotplate set about 160°C and heated. If the oil contains moisture, it produces bubbles and crackles.

Karl Fischer Method is a moisture checking method that is widely accepted. With its precise reading, it gives highly accurate results. A considerable benefit of this method is that it checks free, emulsive, and dissolved water.

The use of Calcium Hydride Kits is also an effective method. A sealed container contains a particular volume of oil and calcium hydride. It is shaken, allowing water in oil to react with calcium hydride. If it carries water, hydrogen gas will come out.

The hydrogen gas produced is proportional to the amount of water.

The FTIR method holds the same purpose; however, it is not as effective as other methods. It can check samples containing about 1000ppm water. Lower precision means less desired technique.

Finally, the use of humidity sensors is a standard method to check moisture levels in oil.

How to Remove Water from Engine Oil?

The next query that arises; how to fix engine oil and water contamination. There are multiple ways to clean your engine oil and make it moisture-free.

Coalescer Strategy

The coalescer method refers to joining water droplets in engine oil to form a bigger water pool. Throw excess water into the drain and reuse the oil.

●      Advantage: you can reuse the oil.

●      Disadvantage: You can only reuse it with low-viscosity liquids.

Centrifugal Strategy

This method separates two liquids with different densities. It removes free and emulsified water from engine oil. Oil is purified and put back into the tank.

●      Advantage: helps remove solid contaminants too. It is a more flexible method comparatively.

●      Disadvantage: initial investments are higher.

Vacuum Oil Removal

Vacuum Oil Removal strategy helps lower partial pressure of engine oil. In turn, it aids water to boil at low temperatures. The dehydrator then dries moisture from the oil.

●      Advantage: removes dissolved water and low-boil liquid impurities present inside engine oil.

●      Disadvantage: costs comparatively higher than other methods.

Air-stripping Oil Removal Method

An introduced alternative to vacuum oil removal and used to remove water, the air-stripping oil removal method is effective against gaseous contaminants.

First, the heated oil draws air. The air mixes with engine oil and absorbs water and gases. Now, the air is released, taking all the impurities within it.

●      Advantage: removes gaseous impurities and dissolved water to less than 100ppm, costs less than vacuum dehydrator.

●      Disadvantage: Although it costs less than vacuum removal, its cost is still high.

Absorption Removal

Filter media absorbs moisture to make engine oil moisture-free.

●      Advantage: it removes solid contaminants and is cost-effective

●      Disadvantage: We cannot use it for a large amount of water present in engine oil.

Prevent Engine Oil from Moisture

Prevention is better than cure, right? Well, the same rule applies in this case. It is better and comparatively cheaper to prevent oil leakage than to fix or replace it.

The issue arises from the cylinder head and gasket. Make sure that the radiator is in good condition with a sealed cap above it. Also, keep checking that your engine’s thermostat and the fan are working well.

Moreover, frequently check the coolant levels of the vehicle. If low, it can cause severe overheating and blow the head gasket.

Leak-proof agents are a cost-effective technique that can come in handy when needed. It softens the rubber packing and prevents oil from leaking. No leaking means no contamination.

FAQs – Does Engine Oil Absorb Moisture?

The questions below will help you regarding engine oil contamination.

Is Engine Oil Hygroscopic?

A hygroscopic refers to a substance that absorbs moisture from the air. Engine oil is hygroscopic by nature. However, the more additives in engine oil, the more hygroscopic it is.

What is Acceptable Water Content in Engine Oil?

Please note that the more additives in engine oil, the more water it absorbs. The acceptable water content in engine oil should be 0.005% to 0.03%.

However, while referring to a specific type of engine, it is a little different. For crosshead engines, acceptable water content should be less than 0.2%. For trunk engines, the water content should be less than 0.1%.

If the water content in engine oils increases, it will wear out the engine’s internals and cause serious harm to your vehicle’s health.

Can I Drive if my Car Engine Oil has water?

The worst you can do to your car is drive when the water range in engine oil increases its acceptable value. Doing so will cause overheating of the vehicle and destroy the engine‘s internals.

It is best not to drive the car under this condition and replace the engine oil as soon as possible.

Final Words

Like most substances, engine oil absorbs moisture too. Don’t ignore your contaminated engine oil, as it can be hazardous enough to cause you serious problems – and that’s undesirable.

Make sure you keep monitoring your vehicle to prevent any unfortunate accidents. If you notice your car overheating more often, or thick clouds of smoke coming out of the exhaust, take your vehicle to repair immediately.

Next time anyone asks you, “does engine oil absorb moisture?” you know the answer – happy reading, happy driving!