If you own a vehicle, you probably know the importance of keeping an eye on your engine’s fluids.
One of the most critical fluids in your engine is the coolant. It is responsible for regulating the temperature of the engine and preventing it from overheating.
However, sometimes coolant can find its way into the engine oil system, causing potential damage to the engine.
In this blog post, we will explore the causes of coolant in oil, how to diagnose the problem, and possible solutions.
Coolant In Oil Not Head Gasket
If there is coolant present in the oil of an engine, it can be an indication of a serious problem.
However, it does not necessarily mean that the issue is with the head gasket.
The source of the problem could be a faulty intake manifold gasket, a cracked engine block or cylinder head, or a damaged intake manifold.
It is essential to determine the specific cause of the issue as soon as possible.
Failure to address the problem promptly can cause severe engine damage, overheating, poor performance, and potentially lead to catastrophic engine failure.
How To Diagnose Coolant Contamination In Engine Oil
Here are some ways to diagnose coolant contamination in engine oil:
Symptoms of Coolant Contamination in Engine Oil
One of the most apparent symptoms of coolant contamination in engine oil is the milky appearance of the oil.
The coolant mixes with the oil, creating a milky or frothy appearance.
The coolant can also give a sweet smell to the oil. Other symptoms of coolant contamination in engine oil may include:
- Engine overheating
- Coolant level dropping
- Coolant warning light illuminating
- Engine overheating in heavy traffic
- Air in the radiator with a full overflow tank
- Bubbles in the overflow tank
Analytical Methods for Coolant Detection in Engine Oil
Fluid Life, a company with over 30 years of experience in oil analysis and lubrication, has developed a proprietary analytical method to detect and quantify the presence of coolant contamination in used (in-service) engine oil.
This method was developed in partnership with Dr. F.R. van de Voort, Professor Emeritus, at McGill University.
The method uses chemometrics to detect the unique chemical signature of coolant in engine oil .
Special Tests to Detect Coolant Contamination in Engine Oil
Detecting coolant contamination in engine oil can be difficult, and sometimes special tests are required.
Coolant contamination can be a phantom contaminant that is difficult to detect directly.
The analytical method mentioned above is an example of a special test to detect coolant contamination.
Pressure Test for Coolant System
To diagnose coolant contamination in engine oil, it is important to first determine if there is a coolant leak.
A coolant system pressure test can be used to identify leaks. In this test, the coolant system is pressurized, and the pressure loss is measured.
If pressure is lost, it indicates that coolant is leaking somewhere in the system.
Other Engine Oil Contaminants to Consider
It is also essential to consider other engine oil contaminants, such as dirt and water, which can be damaging to lubrication systems and engine components.
The Effects Of Using The Wrong Type Of Coolant In An Engine
Here are some of the effects of using the wrong type of coolant:
Corrosion and Damage to Engine Components
Using a coolant that is not recommended for a vehicle can cause corrosion and damage not only to the engine but also to components such as the water pump, radiator hoses, and cylinder head gasket.
The engine coolant should be changed more frequently as the protective layers in the cooling system gradually become thinner and more porous.
Using the wrong coolant or mixing different types together can hinder the car’s performance and may increase corrosion in the radiator.
Using the wrong type of coolant can cause the engine to overheat, especially if the coolant doesn’t have the correct boiling or freezing point.
The cooling system’s flow can be disturbed, causing the engine to overheat, if there is air in the coolant system due to driving around with low coolant.
Clogs and Blockages
Using the wrong coolant can cause clogs and blockages in the cooling system, which can lead to overheating and engine damage.
For example, Dex-Cool, an OAT-type coolant developed in 1995 for GM cars, must never be mixed with other antifreeze types.
As blockages frequently occur when owners mistakenly add green coolant to systems that contain Dex-Cool systems.
Using the wrong coolant can cause leaks in the cooling system, which can lead to a loss of coolant and overheating.
For example, mixing OAT and IAT coolants if they are not compatible can cause leaks and other cooling system problems.
Damage to Engine Gaskets
Using the wrong coolant can cause damage to engine gaskets, which can lead to oil leaks and engine damage.
For example, mixing different types of coolant can cause damage to the cylinder head gasket .
How To Flush Coolant Out Of An Engine Oil System
Here are some steps that can be followed to flush coolant out of an engine oil system:
Identify the problem
Coolant getting into the engine oil system can be due to several reasons such as a blown head gasket, cracked engine block, or a faulty oil cooler.
Identifying the root cause is important before starting the flushing process.
Drain the coolant system
Before flushing, drain the coolant system. Locate the drain plug at the bottom of the radiator and place a pan underneath to catch the old coolant.
Loosen the drain plug and allow the coolant to flow out. Tighten the drain plug when the flow of coolant stops.
Remove the thermostat (optional)
Removing the thermostat can help in the flushing process as it allows for better circulation of the cleaning solution.
However, this step is not compulsory.
Add cleaning solution
After draining the coolant, add a cleaning solution to the coolant system. Dish soap should not be used as it can cause damage to the engine block.
Instead, use a specialized cooling system flush solution that is designed for this purpose.
Pour the cleaning solution into the expansion tank or radiator and fill with water to the fill line.
Run the engine
Start the engine and run it for a few minutes to allow the cleaning solution to circulate throughout the coolant system.
It is recommended to run the engine for at least 45-60 minutes to ensure that the cleaning solution has thoroughly flushed out the system.
Drain the cleaning solution
Once the cleaning solution has been circulated throughout the coolant system, drain it out completely. Loosen the drain plug and let the cleaning solution flow out.
Refill with coolant
After draining out the cleaning solution, refill the coolant system with a 50/50 mix of antifreeze and distilled water.
Make sure to follow the manufacturer’s instructions for the type and amount of coolant to use.
Frequently Asked Questions
What Causes Coolant To Mix With Oil In An Engine?
The most common cause of coolant mixing with oil in an engine is a damaged head gasket.
However, other causes may include a damaged engine block, cracked cylinder head, damaged oil cooler, or a damaged transmission cooler.
It’s important to diagnose the root cause of the problem to prevent further damage to the engine.
How Do You Know If There Is Coolant In The Oil?
A visual inspection of the oil can help determine if there is coolant in it.
Coolant in the oil will give it a milky or creamy appearance. In addition, the engine may also emit white smoke from the exhaust and run hotter than usual.
A proper diagnosis from a professional mechanic is recommended.
Can Drive With Coolant In The Oil Damage The Engine?
Driving with coolant in the oil can cause serious damage to the engine if left untreated.
The coolant can dilute the oil, causing it to lose its lubricating properties, leading to premature wear of engine components.
In addition, it can cause overheating and potential engine failure if not addressed in a timely manner.
Can A Damaged Head Gasket Cause Coolant In The Oil?
Yes, a damaged head gasket is a common cause of coolant mixing with oil in an engine.
The head gasket seals the gap between the engine block and the cylinder head and prevents coolant and oil from mixing.
When it fails, it can allow coolant to seep into the oil passages and mix with the oil.
How Is The Coolant In The Oil Fixed?
The proper repair for coolant mixing with oil depends on the root cause of the problem.
In cases where a damaged head gasket is the cause, replacing the gasket is necessary.
Other causes may require more extensive repairs such as replacing the engine block or cylinder head.
A professional mechanic can diagnose the issue and recommend the appropriate repair.
Is It Safe To Continue Driving With Coolant In The Oil?
It is not safe to continue driving with coolant in the oil as it can cause significant damage to the engine.
The coolant can dilute the oil, leading to premature wear of engine components and potential engine failure.
It is best to have the issue diagnosed and repaired as soon as possible.
How Can Coolant Mixing With Oil Be Prevented?
Proper maintenance of the engine cooling system can help prevent coolant from mixing with the oil.
Regularly changing the coolant and checking for leaks can help identify potential issues before they become major problems.
In addition, performing regular oil changes can help prevent contamination from coolant or other substances.
If you find coolant in your engine oil system, it is crucial to take action immediately. Neglecting the problem can lead to severe damage to your engine and costly repairs.
By understanding the causes, symptoms, and solutions, you can take the necessary steps to prevent this issue from occurring in the future.
Regular maintenance, such as coolant flushes and oil changes, can also help keep your engine running smoothly and prevent costly repairs down the line.