What Does Milky Oil on the Dipstick Mean? | How to Fix Milky Oil in Engine?

If you see milky oil on the dipstick, it usually indicates an issue with the engine or cooling system. Learn the milky oil on the dipstick causes and how to fix it.

Regularly monitoring your oil levels offers a higher chance of detecting issues in their early stages, preventing them from escalating into major problems.

A prime example of such caution comes into play when you come across a milky white substance on the dipstick.

This article deeply explains the causes of milky oil dipstick, presenting both the straightforward solution and the more complex, less desirable scenario.

Causes for Milky Oil on the Dipstick

A milky white appearance on the oil dipstick usually signifies the presence of water in the oil. This mixture results in the formation of a whitish sludge. Given that water should never be present within the engine, it’s crucial to investigate the root cause of this issue, as it might be connected to a faulty head gasket.

The following are the most common causes of milky oil dipstick.

1) Coolant Contamination

Coolant contamination is one of the major causes of milky oil in the engine. If your vehicle’s engine cooling system is leaked due to a cracked engine block or a blown head gasket, coolant may mix with the engine oil.

The engine coolant most commonly contains a color and has a sweet smell. As it is mixed with oil, it may lead to a milky appearance on the dipstick.

Read More: Causes of Oil in Coolant

2) Wrong Oil Type

The use of the wrong oil type may also cause milky substance accumulation in the engine. Therefore, it is recommended to use the best suitable oil for your vehicle. Consult your vehicle’s service manual to find the best oil suitable for your vehicle.

3) Condensation

One of the most common causes of milky oil is condensation.

If you live in a region contending with higher levels of humidity and dampness, then your engine might accumulate moisture. You may observe this issue through the emission of water vapor in the exhaust gases.

Normally, as the engine attains normal operating temperatures, this moisture evaporates. Yet, not all drivers cover sufficient distances to sufficiently heat up the engine, resulting in moisture lingering within the motor. If this condensation is overlooked, it may culminate in the development of a milky white substance on the dipstick.

Furthermore, water could have infiltrated the engine during engine bay cleaning activities. Employing a pressure washer, for instance, might inadvertently introduce water into the oil. Similarly, water might find its way through the air filter or the power steering cap, all of which pose undesirable outcomes.

4) Bad Oil/Coolant Heat Exchanger

Certain vehicle engines contain a heat exchanger designed to regulate oil temperature by leveraging the coolant temperature. Occasionally, a gasket within these heat exchangers can deteriorate, or the exchanger itself might develop an internal crack. Consequently, this situation can lead to the appearance of milky oil on the dipstick.

Nonetheless, it’s important to note that the majority of car models lack this component. To determine if your engine features a heat exchanger, it’s advisable to consult your owner’s manual or conduct further research.

5) Blown Head Gasket

For anyone familiar with engine issues, encountering a blown head gasket is a scenario best avoided. A blown head gasket may also cause milky engine oil on the dipstick.

The head gasket’s crucial role lies in maintaining a hermetic seal around the cylinders. This seal ensures proper cylinder function by maintaining the required compression levels. Moreover, the gasket serves to separate coolant and oil, even though both coexist within the engine.

In the event of a blown head gasket, the coolant begins to seep into the combustion chamber or the oil lines. The outcome is the appearance of a clear white, milky substance on the dipstick.

This issue of a blown head gasket doesn’t come alone; it’s accompanied by other discernible symptoms.

Experiencing engine overheating or observing white smoke emanating from the tailpipe are clear symptoms of a blown head gasket. Likewise, you might detect air bubbles in the radiator or coolant overflow tank. If you’re frequently refilling coolant without detecting any external leakage, it’s plausible that the coolant is leaking into the oil passages instead. 

How to Fixe Milky Oil on Dipstick

Follow the below-given steps to fix milky oil on the dipstick:

1) Drive For A Long Time

If your engine is in good condition, it’s feasible to eliminate any internal moisture by following a simple approach. Extending the duration of your typical short trips can facilitate the evaporation of condensation within the engine.

For trips lasting under ten minutes, the engine might not achieve the optimal operating temperature, particularly during casual town drives. To counter this, consider dedicating more time to your journey.

 Opting for a lengthier route to your destination, especially if you anticipate a prolonged period without driving, is recommended. Additionally, attaining speeds of around 60 mph is beneficial, as it expedites the dissipation of condensation compared to driving at 25 mph.

2) Replace the Blown Head Gasket

Identifying issues with a heat exchanger can pose challenges unless you possess the appropriate expertise. Engaging in online research to ascertain whether other individuals with the same engine have encountered similar problems is recommended.

A proliferation of reports about failed exchangers on your specific car engine model might suggest a common issue. To diagnose a problematic heat exchanger, you’ll either need to conduct a thorough inspection involving the removal of the exchanger to assess the gaskets or employ a pressure tester.

Once a head gasket failure is confirmed, the available options become limited. A multitude of head gasket sealers are available in the market. While some caution against their use, the decision to use one should be based on your judgment of what’s most suitable for your vehicle. It’s worth noting that the use of a sealer is unlikely to worsen the situation, so it could be a viable avenue to explore.

3) Clean Your Engine

If you’re considering cleaning your engine bay, undertaking the task yourself is possible, but exercising caution is essential. Preventing water from infiltrating the engine is paramount to avoiding significant damage.

Prior to commencing, remove the oil cap and assess its seal. If the seal displays signs of wear, it’s imperative to replace it beforehand, as a compromised seal can’t effectively prevent water from entering the engine.

With a well-maintained seal, proceed to lightly spray the engine using a low-pressure setting. A regular household pressure washer can be employed for this purpose, but it’s crucial to select the lowest pressure setting capable of accomplishing the task. However, it’s crucial to refrain from directly spraying the engine seals, as they are not designed to withstand such pressure.

Alternatively, an engine degreaser can be employed to achieve a clean surface. Utilizing a scrub brush and the cleaner, you can effectively eliminate debris. Subsequently, a small stream of water is sufficient for rinsing, minimizing any risk of introducing oil into the engine.

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