What Does Oil in Coolant Look Like? (Explained)

What Does Oil in Coolant Look Like

Cars can develop a fault with time but to ensure you get the best out of your car; a consistent routine check should be done by you or a professional. This will help discover what problems your car may have, is having, or is likely to have.

A coolant is as important as a car engine. It ensures a circulation of fluid around the engine is possible. A routine check on this is required to ensure the engine is safe. Therefore, what if oil enters the coolant? What does oil in coolant look like?

Oil in the coolant will look like a thick, milky, or gravy-like substance which will do more harm than good to your engine if not replaced and the cause traced and fixed.

Can Oil Mix with Coolant?

Yes, there are possibilities for car owners to experience oil mixing up with their coolant. It is a serious problem that requires immediate attention.

When oil mixes with coolant, it can cause serious damage to the car engine, causing you to either get a new one or spend costly on fixing a sustaining repair.

Your oil shouldn’t get mixed up with your coolant because they are both separate parties with separate spaces. It is possible for this to happen, but it isn’t a normal thing and it is dangerous for the car engine.

What Causes Oil to Mix with Coolant?

Oil in your coolant is expensive and you need to know why this is happening, so next time you can prevent it from happening. Here are a few details to why oil can mix up with your coolant:

1. Your Oil Cooler is Probably Cracked

You can find oil cooler filters in almost every car because it is modern. A crack in the oil cooler will cause a leak in which the oil escapes into the coolant.

Depending on how cracked the oil cooler is, it is reasonable to act fast in replacing it before it causes severe damage to the engine.

It is cheap to replace your oil coolant. It wouldn’t cost you much compared to how much cost you would bear if anything goes wrong with your engine.

A daily routine of checking these few details will help you discover if your oil cooler is aged enough to be changed before it develops a crack.

2. Your Cylinder Head is Probably Cracked

The major problem with why your oil leaks are because of a crack somewhere in your vehicle. When your engine experience consistent overheating, it causes a crack in the cylinder, which isn’t good for the engine performance.

The cylinder head is built in such a way that it can only take it with no heat or a limited amount of heat. If the engine produces more heat than expected, the cylinder cracks, and the air and oil contents in its escape.

If you notice this, a quick replacement should be done. The price varies depending on what model of the car you are using and who will do the replacement for you.

3. A Crack in the Engine Block

Your engine producing too much heat isn’t good for the car. When there is excessive heat, the engine block also experiences some cracking; it cracks because of limited oiling and excessive heating.

Anytime there is a crack, the oil leaks out straight into the coolant.

You need to do as many checks as you can to always prevent this from happening because repairing this will require replacing the engine most times and it is quite expensive to get it done.

What Does Oil in Coolant Look Like?

If you notice a thick, milky, or gravy-like substance, be sure your oil is mixed up with your coolant and you need to act fast in rectifying the issue before things go south.

Oil is expected to float, after opening your radiator or your coolant tank, when you see separate mixtures, then you have oil in your reservoir, as the coolant and oil mix and the engine runs, it will turn out into a sort of milky liquid.

What Color Is Oil Mixed With Coolant?

A milky liquid is formed because of oil mixing with the coolant in a functioning engine. When this happens, tracking out the leaks and flushing out the contents from the radiator should be the utmost priority.

What Happens If Oil Gets Into The Coolant?

Do you want to avoid this nightmare? Having your oil mix up with the coolant will cause your car to experience severe overheating, causing more cracks to other places of the car, and causing the engine to be seriously damaged, sometimes beyond repair.

Most of the time, a replacement will be done, which is expensive and might cost your car to stay a little bit longer with the mechanic.

A day-to-day routine of a few basics of your car can help you detect a fault fast before your engine gets affected.

How to Get Rid Of Oil in Your Coolant

You can do it yourself. You don’t need to hire a professional to get rid of the oil in your coolant. Check out the details below on the easy way to get it done.

1. Have the Car Prepared

Take away the radiator cap, and open the top of the overflow bottle. Kickstart the car, and keep it steady enough until it’s warm.

Find a dishwasher detergent that foams less or find a liquid dishwasher that doesn’t contain 4-D Butyl Ester to prevent a reaction with the coolant content.

Use ¼ if you will use the liquid and ½ if you will use a detergent dishwasher. Pour the dishwasher content into the overflow bottle so it can foam.

Don’t freak out when it foams, it is a good sign…

2. Have it Flushed Out

Keep a drain pan underneath the radiator and open up the bottom valve of the radiator so as to drain down the contents into the pan. You might likely require over one pan to finish the entire process.

Have your hose ready, point the nozzle into the overflow bottle or into the radiator directly, and flush out the contents with a hard flow enough to replace the coolant that is gushing out through the bottom of the radiator.

3. Have the System Cleaned

Have the draining continue until the coolant system is free from foaming completely. Ensure the hose is running and replace the drains in the drainage systems.

Never allow the coolant to drain itself into the earth, it can be highly toxic and can cause pollution.

After your coolant system is free from any traces of form because of the dishwasher used, ensure you turn the engine off and close up the radiator cap.

Ensure the coolant system is full of water and the drain pans are emptied appropriately.

4. Flush the System Again and then Refill

Keep the system flushed again by draining out and using the hose to bring more water into the cooling system to ensure the oil is expunged.

Ensure the engine is turned on while doing the flushing and, once you are done with refilling, turn off the engine. Ensure during refilling, you use 50% distilled water and 50% coolant.

Can I Drive My Car With Oil In My Coolant?

It is dangerous to drive your car with oil mixed up in the coolant. It can cause a severe overheating of the car and which is likely to lead to a damaged engine. Never take your chances. If you notice any symptoms, reach out to a professional as early as possible.


Oil in your coolant is dangerous and can be pretty expensive when it causes your car engine to get severely damaged. A consistent routine, and keeping check of the car is a good way to detect any crack or issues before it causes a bigger problem.