Discovering oil in your coolant reservoir can certainly ruin your day. In this post, I’ll go through in detail the most common causes of oil in coolant and how to remedy this problem.
There are various causes of oil getting into coolant that you should be on the lookout for, hence this article. Do remember that coolant in oil and antifreeze in coolant are two different problems and warrant different levels of attention.
It is my hope that, for the sake of saving you hundreds of dollars in parts costs, I’ll let you into a little trick that I’ve used in the past. It will cost you less than $60!
How do I know if there is oil in my coolant?
When you take off a radiator or coolant reservoir cover, you should see the color of your antifreeze in the reservoir tank.
If you see oil getting into coolant, there would be a residue of oil seen in the radiator cap.
There are different antifreeze colors. Depending on your engine coolant specification, your coolant could be red, green, orange or pink.
Now that you have removed your coolant reservoir tank and seen an oil-like substance, you probably have oil getting into your coolant somewhat.
You may wonder, what does oil in coolant look like? Well, if you have an oil and coolant mixture, you would see a milky color liquid in the reservoir tank. Failure fix this issue promptly, will cause catastrophic damage to the engine.
What causes Oil in Coolant?
There are many reasons this may happen. Let’s quickly run through the possible causes.
#1. Leaky Head Gasket.
The gasket referred to here is the one that lies between the head cylinder and engine block to prevent coolant and oil from leaking out or into each other.
If your vehicle has a blown head gasket, it can cause oil and antifreeze to mix which may have caused your issue. If you have Overheating with oil residues in coolant as well, it indicates a blown head gasket that requires proper attention.
You can either take your car to the mechanic garage or get a head gasket tester kit and see if the head gasket is to blame.
Suppose the head gasket tester determines that a leaky head gasket is a culprit, you will contact your mechanic to pull off your head cylinder and replace the lousy gasket.
Or you read on to find the trick I use to repair leaky head gasket without pulling off the engine. I really do not recommend you to attempt to pull off cylinder head yourself unless you’re a certified mechanic.
#2. Oil Cooler.
Some cars are equipped with oil coolers. These help the motor oil to be at the optimum temperature for operations in the engine. There is a little crack in the oil cooler, which will cause oil and coolant to miss their passage route-ends up being an oil and coolant mixture in the ending.
This can cause other issues to your cooling system. So, you should fix it within the time you notice it. As a DIY enthusiast, you can replace the oil cooler. It does not take much skills.
#3. Overheating.
An Overheating engine will damage your head gasket at a faster pace. Once you have a damaged head gasket, it’s for sure going to cause oil and coolant mixture which can be the cause of Oil in your Antifreeze.
#4. Cracked Cylinder head.
Sophisticatedly speak, if you have a cracked head cylinder, it’s going to make Oil to mix with your coolant. The best way to detect if you have a crack in your head cylinder is to let a mechanic pull out the head cylinder so you can inspect it properly.
If you see cracks in the one you inspected, you can replace your entire engine or just the head cylinder. Whichever you chose is going to be cheap to go and buy another for replacement from your local dealer, and you will be good to go.
#5. Damaged Engine Block.
Damaged Engine Block will be the cause of Oil in Coolant, not the head gasket. This is the least scenario to happen due to how resilient the engine blocks are.
If you have a damaged engine block, the best option is to buy a new or fairly used engine, and have your car running again.
How to fix oil in coolant?
How to fix coolant mixing with engine oil could either be a complicated or straightforward fix depending on what the problem is caused by.
First, you would want to drain out the old contaminated coolant from your radiator petcock or down hose that you won’t have contaminated antifreeze in your car.
Depending on your findings, you would want to face the problem either by repairing or replacing the cause which could be friend leaking head gasket, cracked head cylinder, oil cooler or transmission cooler.
Once you have replaced or repaired what caused the mixing you want to fill your coolant tank with your recommended antifreeze. You can refer to your owner’s booklet to know the right coolant for your car.
The next thing to do is to go for a test run. If you observe any new residues of oil, you want to start double-checking other possible causes and fix them thoroughly. But if there is no sign of oil residues in your coolants? it means you have done an excellent job.
Remember, I promised to show you the trick that I have been using over the years? That said, if you want to know how to remove antifreeze from engine oils or how to stop oil and coolant mixing, you will find the correct answer, in the next few paragraphs.
If you don’t want to spend hundreds of dollars repairing this fault, you can try the steel sealant.
To use the steel sealant method, you want to make sure that you flush your radiator with a water hose until there is only clean water coming out. The clean water shows that you have successfully flushed out the contaminated coolant out of your system.
Next, refill your radiator with a distilled water and pour a bottle of a steel seal or a blue devil. (There are other steel sealant out there, but I recommend these two product).
Then turn your engine on and allow it to idle for about 1hour. You want to make sure you blast your heater and monitor the temperature. Once the engine had idled for 1 hour, you want to turn off the car and allow it to cool down.
After 30 minutes, open your radiator or reservoir cap and inspect for new oil residues. If your coolant is clear of oil residues? it means you have done a quick fix.
The next thing you want to do is to do a test-run. You have to baby the baby for the sealant to have a better chance to do its work.
Some head gasket holes are unfortunately big enough for it not to work on. However, it remains the best first option to try out.
FAQs.
Q: Can I use vinegar to flush my radiator?
Vinegar is ordinarily a 5% mild acetic acid. It is good in itself to use for the purpose of the removal of system rust.
All you do is, to add a gallon of distilled water and vinegar and turn the engine on. Let it run at idle for 30 minutes or so. Don’t forget to blast the heat to clean your heater core out also. Vinegar may be used to flush a clogged radiator.
Q: Can you drive a car with oil in Coolant?
Oil and coolant have a different passage approach, hence driving your car or truck with oil in coolant but no coolant in oil. The limits located on your vehicle are not as forgiving as those on our bodies.
It will most likely be catastrophic to the engine which damage rendering you to do costly engine repair or total engine replacement.
Q: What happens when oil mixes with coolant?
If you find oil mixes with coolant then you need to find out the cause of the problem.
If you pay no attention to it then motor oil will lose its viscosity also lose its lubricating power consequently causing engine Overheating that might in the end blow your engine.
Final word
At this juncture, I believe this article has adequately answered all the questions you may have concerned oil in the Coolant Reservoir.
We have effectively highlighted the symptoms, causes and how to fix this problem. So, once you notice oil mixes with coolant you can try the quick fix method first, or contact a professional mechanic to have your vehicle inspected and repaired.