Oil in Coolant Reservoir: Common Symptoms, Reasons as well as Solutions

oil in coolant

Every Car User must have to be aware of the Coolant. If you open the front hood of your car, you can see the Coolant reservoir Plastic tank in the engine bay. In the reservoir tank, you will see a green or light red or orange color coolant. You should top up the coolant level if you notice it low. But one thing you need to keep in mind that you should always use the same color coolant that is in the reservoir. 

Every car user should check the coolant level regularly. Many car users ask us why their coolant color is becoming milky or why there’s oil in the coolant. Most of the car users do not know the main cause of this and very few users are aware of it. 

Okay, don’t worry. We will discuss the details of this issue, its reasons, and how can you solve it.

Engine Oil and Coolant Functions:

The function of Oil and Coolant is a little similar to each other. Both of them minimize the temperature at different places and in different ways but you shouldn’t mix them. Here is how they work:

Engine Oil: It’s a Lubricant. Each movable part of the engine produces a high amount of heat. The engine oil controls this heat. If the temperature is increased so much any kind of metal will be swollen. Oil reduces the frictional temperature of the metals and protects the parts. It also helps to move the parts smoothly. So we always suggest using proper and quality engine oil.

Coolant: Without the cooling system you cannot find a modern engine. It can be an air-cooled engine or a liquid-cooled engine. These two types of engine cooling systems are popular in the automotive industry. We are talking about the liquid-cooled engine here. This system operates by sending the coolant through passages in the cylinder head and engine block.

The coolant continuously moves through the engine head and the engine block to the connected radiator with a rubber hose. The coolant picks up the excess heat and reduces it. Besides, it helps to make the engine run perfectly. 

Possible Reasons for Oil in coolant:

Head Gasket: The head Gasket plays the most important role in any Engine. It makes the engine Separated from the Engine Block, and seals the Oil and Coolant line of Engine head and block. If the Head gasket is blown, oil goes to the coolant or coolant goes to oil and get mixed. 

Oil Cooler: Engine Oil Temperature is controlled by the Oil Cooler. If the Oil Cooler is faulty or internally cracked or it has any leakage, the engine oil and coolant will get mixed.

Engine Head: Another significant reason for oil in coolant is cylinder head internally cracked or water line is worn out badly. You can minimize this issue by following the proper maintenance guideline of your car. Use proper coolant and fulfill the shortage from time to time. Keep your eyes on the dashboard. 

If you observe your temperature indicator is crossing the red level, you should check the engine cooling system and fix the issue. If you don’t fix the issue and continue driving, your car engine cylinder will get cracked or damaged.

Engine Block: Frequently overheating and careless mentality minimizes your car life as well as your engine block’s life. It can be internally cracked. Cracked engine block causes a little amount of oil in the coolant. The amount can be high. It depends on the engine block’s condition and how much it is cracked. 

Engine Overheating can make the Head gasket Blown. Broken or cracked Engine head and engine block can cause the oil in the coolant.

Do you know what are the main causes of engine overheating? There are a few reasons for making your engine overheated. Those are:

oil in coolant

Radiator: If Your Vehicle Radiator is clogged, inside Coolant can’t move properly as well as air supplied from the radiator fan can’t reach. As a result, the engine becomes overheated. So, if you notice the temperature gauge of your dashboard is increasing, you must stop the vehicle and solve the issue as soon as possible. We don’t recommend driving with an increased temperature gauge.

Radiator Fan: Sometimes, radiator fan failure can cause engine overheating. So, you must check the radiator fan if your engine is overheating. If you find it defective, change it as soon as possible.

Temp Sensors: Faulty Temperature Sensor Cannot indicate the proper temperature of the coolant. As a result, you can’t understand if your car engine is getting overheated. But if you’re a smart driver, you can easily understand.

Your vehicle will not run smoothly, fuel consumption will get high, and the air conditioning system performance will be poor. If you run your vehicle with an overheated engine, your engine head and engine block will be cracked. 

Water Pump: If your Vehicle water pump is leaky or damaged, your car engine will be overheated. So, you should be aware of the water and you should be able to understand the symptoms of a bad water pump.

Thermostat: Another issue is the thermostat. The function of this component is to keep the coolant at a standard temperature. This helps at operating the engine smoothly. A faulty thermostat cannot open in time. As a result, the engine gets overheated quickly.

Oil In Coolant “What to Check when you find Oil in Antifreeze” YouTube Video :

How to fix oil in Coolant:

Coolant and Oil both are very much important for the Engine. They should not be mixed. If you observe oil in the radiator reservoir tank, it’s an abnormal case and you should check it out. It means there is something wrong. So, you need to find out the actual reason or you can take your vehicle to an experienced mechanic.

Okay, to help you understand in a more specific way, here are some tips regarding this issue. 

If you fill the ATF or Engine oil in the Coolant reservoir by mistake, you should flush the cooling system completely. You can do it by yourself or you can get help from a professional mechanic. Don’t run your vehicle with a diluted coolant. If you continue the vehicle, it will be overheated constantly. By the by, it can damage your vehicle engine too! So, you must have to be serious about this issue and solve it as soon as possible. 

Another thing is, if you cannot identify the problem, you must take the vehicle to a garage nearby or call a mechanic for solving the problem. If your problem is at the intermediate level, it will take a little time. Just cleaning some components and replacing the oil filter will help at making your problems eliminated. If you got problems of an extreme level, it would be better to overhaul the complete engine.

In general, lack of proper maintenance of car users can make this issue. This issue not only wastes your coolant and Oil but also damages your car engine. So, we always suggest taking good care of your car and resolving the problems when they’re at the intermediate level.

oil in coolant

Frequently Asked Questions (FAQ)

What does it mean when there’s oil in the antifreeze?

Ans: It means something’s wrong with the cooling system or lubricating system. It can happen if the head gasket is blown, or the oil cooler is problematic, or from the cracked engine head or block.

Can you still drive a car with a blown head gasket?

Ans: No, you cannot! If you notice your car head gasket is already blown, it should be fixed as soon as possible. Only then you can drive the car. If you drive the car with a blown head gasket, it’ll cause complete engine damage.

How can you tell if there is coolant in your oil?

Ans: We have already discussed this issue. If you feel your car engine Is knocking, the temperature is increasing, abnormal noise or unsmooth driving, you must check the engine oil level by oil deep stick gauge.

What happens if you put engine oil in the coolant?

Ans: Don’t do it! If you’ve done it by mistake, so many things can happen. Such as your vehicle engine will get damaged and you should not start the car until the issue is fixed.

How do you know if your Head gasket is blown?

There are so many Symptoms that will indicate your head gasket is blown. Such As: 

  1. Coolant leaking through the Exhaust manifold
  2. White smoke from the exhaust 
  3. Loss of coolant with no visible leaks
  4. Engine Overheating
  5. Bubbles in the radiator while opening the radiator cap or overflow tank
  6. White, milky oil
  7. Poor engine performance 

Also, Learn More by Reading our articles. Click here 

Final Words:

Little Leakage of cooling system lubricant can create this problem. It seems like a minor but this minor problem can be a big problem. Whenever you see Oil in coolant reservoir, you should fix the issue immediately. We hope you understand how much damage can happen to your car if you avoid it. 

So, save your car and save your money and time. Take good care of it.

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