How To Remove Antifreeze From Engine Oil (9 Steps & Cost)

Does your car’s antifreeze mix with engine oil? Or Do you accidentally put coolant in engine oil? 

No matter what. At first glance, it seems to you a complete oil disaster for your engine system. Because your car won’t appreciate it to run smoothly. 

So, what’s the solution to running your car’s engine to its optimal performance? Yes, it is removing antifreeze from engine oil and pouring new company-recommended oil into its reservoir. But, to do that, it’s important to know how to remove antifreeze from engine oil. 

Don’t panic, as removing antifreeze oil is a DIY job with little patience. This guide is dedicated to letting you know the step-by-step instructions with simple words. So, you can effortlessly change the antifreeze oil. Let’s get started together. 

Antifreeze In Oil Causes

Yes, it’s tough to detect why antifreeze is mixed with engine oil. But, solving the issue without knowing its reasons isn’t a great idea. As it can repeat the antifreeze mixing with oil, so this head-turning problem may appear again. That’s why, here we enlist 5 possible antifreeze in oil causes for your convenience. 

  • If there is any leaking in the oil cooler, the antifreeze may seep into the leak and mix with the engine oil. 
  • The blown cylinder and the head gasket may be the most common reasons for leaking antifreeze. When the head gasket blows, it mixes with the engine oil.
  • If your engine overheats during running, it may cause coolant system failure, a faulty water pump and radiator. Any of these can affect the coolant and oil passing system. As a result, you may face antifreeze in the oil. 
  • Though the engine block is durable enough to last longer, it can damage due to age or other reasons. The antifreeze may mix because of the damaged block engine. 
  • If your vehicle has a transmission cooler and somehow it cracks or leaks, that can also be a reason for antifreeze in the oil. 

How To Tell If Antifreeze Is In Oil 

There are a few symptoms and signs to determine antifreeze in engine oil. Knowing the signs and observing your engine can help you to tell if antifreeze is in the oil or not. 

  • Antifreeze is thinner than engine oil. The engine oil viscosity will deteriorate if antifreeze is mixed with it. 
  • You may face less lubrication and frequent engine oil breakdown for the presence of antifreeze in the oil. 
  • If the antifreeze is mixed with the engine oil, you’ll notice a brown, red, or green mixture in the engine’s crankcase. When the engine runs, all those contaminated particles turn the oil creamy like coffee. 
  • If the coolant enters the engine oil due to coolant leaking,  the coolant level will drop out sooner. So you may face regular coolant loss. 
  • If the antifreeze dissolves into the oil, it leaves a sweet odor. To check the odor, you have to remove the dipstick from your engine oil reservoir, and try to smell it. If you get a sweet aroma, you should understand the antifreeze is mixed with the oil. 

Most of the cases, all of these signs won’t appear at a time. If you find any of these signs matches with your engine, that might be the reason for your antifreeze in engine oil. 

How To Remove Antifreeze From Engine Oil 

Removing antifreeze from engine oil is a really cheaper option than repairing your engine. So it’s time to learn how to fix coolant mixing with engine oil. 

Step 1: Determine the causes

Your first task is to determine the causes of why and how antifreeze and engine oil get mixed. Otherwise, removing the coolant won’t be effective for you because they will get mixed again within a few days. 

Note: If you find the cause and that is a DIY job, you should repair it first. But, if that needs professional mechanical engineering expertise, you should take your car to a garage and seek professional help. 

You can skip this step if you accidentally put coolant in engine oil

Step 2: Keep the engine cool

You shouldn’t run the car to keep the engine and the oil cool. Because when the engine remains cool, the antifreeze won’t mix with the oil. Instead, it goes to the bottom of the sump. So it helps you to remove the oil with all contaminated particles. 

Step 3: Prepare the car 

Now, park the car on an even surface and engage it with an emergency brake. Turn the engine off and place a jack below the car to raise it. So that you can easily reach the oil-drain plug, which is located underneath the car.

Step 4: Reach the oil drain plug 

You should wear safety goggles and hand gloves to avoid getting you messy. Crawl under the car and reach the drain plug. Keep a drain pan exactly below the drain plug. You should choose a pan that can catch a good amount of oil that you predict to drain. 

Step 5: Remove the antifreeze engine oil

Now, open the drain plug with a 6-point socket or an adjustable wrench. As soon as you remove the plug, the antifreeze oil starts to drain. Wait a few minutes until a single drop of antifreeze mixture oil drains from the oil reservoir. 

Step 6: Secure the drain plug

The space may be getting messy due to dirty oil. So clean the entire oil-draining space with a rug. Replace the plug with the socket or wrench from where you open it. If the plug is not in that good condition, it’s better to use a new one. 

Step 7: Pour new oil

You need to open the car’s hood to reach the oil reservoir. Remove the oil-filling filter plug with a wrench. Wipe the space to clean the surrounding particles. Pour your car’s manufacturer-recommended oil till the reservoir neck. Don’t overfill it, as the oil may overflow when you run the engine.

Step 8: Reinstall the filter

How you open the oil-filling filter plug, reverse the process to reinstall it. Ensure the plug is tight enough not to leak oil. 

Step 9: Test the engine 

Slowly and safely remove the jack stand from the car to get it down on the ground. Start the engine and run the car for 1-2 minutes. Observe your car while running whether antifreeze or oil still gets mixed or not. If not, congratulations. You have successfully done the job. If yes, check where it leaks, and repair it. 

How Much Does It Cost To Remove Antifreeze From Engine Oil 

Various factors will influence the overall cost of removing antifreeze from engine oil. So it’s very tough to inform you of the real cost, as it depends on many parameters. Here we just let you know some situations and their cost. So, you have an idea about the cost. 

  • If you accidentally put antifreeze in engine oil, your oil will be wasted. And if you remove the oil yourself, the oil price, approximately $15-$25 is only your cost.  
  • If the antifreeze gets mixed due to coolant leaking, it needs diagnosis. If you can find it, that’s good. But if you need mechanic help, the coolant leak diagnosis cost may be around $43 to $55. It may add more than $100 to $1000 to fix the leak depending on your needed materials, location, mechanic expertise, etc. 
  • If that needs transmission cooler repair, you must purchase a new radiator and consult the transmission service provider. This total package may cost you approximately $350 to $450. 
  • If antifreeze leaks due to a blown head gasket, you must replace it. This repair may cost you around $1200 to $2000, including material and labor charges. 
  • If your engine block is damaged, and for this, you find antifreeze in the oil. You should replace it entirely. The engine block is a pricy automobile part, and requires an expert automobile mechanic for replacement. It costs you a higher amount, like $4000 to $8000.

So, after analysing your car condition, you may get an idea how much you may need to spend to remove antifreeze from engine oil 

What Happens If Antifreeze Won’t Be Removed From Engine Oil 

You have to face some consequences if you don’t remove the antifreeze mixture engine oil. Such as 

  • Lubrication deprivation won’t support your engine to run for a longer time. 
  • The engine’s internal parts’ frictional engagement will increase. 
  • Excessive metallic engagement will reduce the engine’s performance. 
  • The fuel consumption and releasing toxic emissions also increase. 
  • Antifreeze produces an acidic condition in engine oil. If that isn’t solved, gradually, it impacts or may damage the entire engine. 


Does antifreeze in oil damage engine?

Both yes and no are the straightforward answers to this question. Antifreeze in oil won’t damage the engine instantly. But gradually reduces the oil’s viscosity grade, lubrication efficiency, and increases oil breakdown. So, in the long run, it’ll damage the engine. 

Oil in coolant reservoir but car not overheating? 

The car engine has two seals or gaskets. If there is coolant in the oil, in most cases, it fails one of the gaskets between the two. So the other gasket can help to smoothly flow the engine oil to lube its parts and prevent the engine’s overheating. 

Final Words 

Once you notice antifreeze in oil, you must instantly attempt to remove it to avoid long-run damage. You can easily replace the antifreeze mixture engine oil following the process that we described. But, if you aren’t confident, it’s better to take professional help. 

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