Engine Oil Leak Repair Cost: Causes, Symptoms, Costs, and Fixes

The proper supply of engine oil is very important for the efficient working of the engine. When the oil is leaked, it starts to decrease immediately. An engine oil leak produces different signs. Immediate attention to an oil leak is crucial to prevent yourself from an expensive repair cost.

engine oil leak

The sight of oil seeping from under the vehicle can momentarily halt your heartbeat as you contemplate the potential costs involved. Undoubtedly, engine repair is one of the most expensive parts when it comes to vehicle maintenance. This article explains the engine oil leak causes, symptoms, and repair cost.

Common Oil Leak Causes

Following are the major causes of an engine oil leak:

1) Bad Oil Filter

Oil Filter

A bad oil filter is one of the major causes of an oil leak. Although it is not a frequent occurrence, the filter housing can sustain damage, leading to leaks. In some cases, internal engine pressure may cause the oil filter to loosen with time if it was not initially secured tightly enough.

Similarly, over-tightening the filters during installation may also result in gasket damage. Additionally, while changing the filter, if the old gasket of your vehicle sticks to the engine, it can lead to oil leaks.

It is crucial to maintain the integrity of the oil filter to prevent dirt of the engine oil from entering the engine and causing damage. Generally, if your filter is regularly changed as recommended, it should continue performing its function effectively unless a defective one is installed.

2) Faulty Gasket

Blown Head Gasket

Gaskets are essential components that ensure proper fluid containment within the engine. They also regulate the flow of oil during its pumping throughout the engine.

However, the gaskets of your vehicle have a limited service life and gradually degrade over time, eventually becoming weak enough to allow oil seepage. Typically, this degradation should not occur before reaching 100,000 miles, but if your engine is subjected to continuous use, it is not uncommon for it to happen sooner.

3) Excessive Amount of Oil

In the event that you recently added oil, a small error may lead to the leak. It is possible that during the oil change, you might add the excess amount. In such cases, removing the surplus oil is all that is required.

Another likelihood is that oil was spilled while you changed the oil. Cleaning up the spill with a rag is recommended.

4) Damaged Oil Filler Cap

Oil Filler Cap, reasons of oil leak

If you observe rapid oil puddles forming beneath your vehicle or near the engine, it means that there is something wrong with the filler cap connected to the valve cover.

Over time, the oil filler cap may become loose or easily break when detached. Additionally, it is possible that the oil filler cap was unintentionally left off after an oil service.

Fortunately, this is typically one of the simplest issues to address. If readjustment of the cap does not solve the issue, replacing the cap is a viable solution.

5) Faulty Crankshaft Seals

Crankshaft Seal, causes of engine oil leak

A damaged crankshaft seal is also one of the most common causes of oil leaks. The engine has two spots where you can see the crankshaft sticking out a little bit. These spots have special seals designed to prevent oil from leaking. The crankshaft comprises rear and front seals.

When the front crankshaft seal is damaged, the engine oil may start to accumulate towards the engine front, near the belt. Alternatively, if you notice oil between the transmission and the engine, it may indicate a leak in the rear crankshaft seal.

Read More: What Happens If You Add Wrong Oil?

Symptoms of An Engine Oil Leak

You can easily identify the oil leaks by different symptoms such as dark puddles under your car, smoke from the engine, oil light, engine overheating, burning oil smell, or poor engine performance.

Following are the major symptoms of an engine oil leak:

1) Dark Puddles Under your Car

Dark puddles under car

The dark puddles under your car are one of the clear symptoms of an engine oil leak. While driving your vehicle, be vigilant for yellow or dark brown puddles.

If you don’t have a specific parking area, consider placing a cardboard piece or plastic plate under your vehicle when parked. This will help you figure out if the oil leak is coming from your vehicle or from another car. If your oil pan is leaking, it can cause oil to spill directly onto the ground, which may cause problems with the oil level and oil pressure in your engine.

2) Poor Engine Performance

Poor Engine Performance, symptoms of oil leak

Insufficient lubrication due to an oil leak can lead to increased friction and wear on engine components. This can result in decreased engine performance, such as reduced power, rough idling, or misfires.

3) Oil Light

oil warning light

When the oil light starts to illuminate on your vehicle dashboard, it’s a very important warning that you shouldn’t overlook. It means that the oil level or pressure in your engine is too low. It doesn’t always indicate an oil leak, but you should get your car checked to find out what’s causing it.

4) Burning Oil Smell 

oil smell

When oil leaks onto the hot metal components of the engine, you may detect a distinct burning oil smell and hear a sizzling noise. The sizzle occurs when the leaking oil makes contact with the heated engine components.

If you observe a thick, bitter odor resembling that of burning oil and hear a noise similar to bacon frying under the hood, it is likely an indication of an oil leak.

5) Engine Overheating

Symptoms of Engine Overheating

Engine oil plays a crucial role in regulating the temperature of the engine. It provides essential lubrication to the pistons, ensuring their smooth movement within their casing.

Insufficient lubrication can result in the pistons grinding against other engine components, generating excessive heat and potentially causing engine seizure and stalling. Additionally, an oil leak can lead to engine overheating if the oil level drops more than a specific level.

Read More: Engine Overheating Symptoms and Causes

6) Low Oil Level

If you regularly check your engine oil and notice a gradual decrease in the oil level despite not having performed an oil change, it could indicate an oil leak.

7) Smoke from the Engine 

If oil enters the exhaust manifold, it may produce smoke emanating from the engine. It’s important to know that ignoring an oil leak for a long time can cause damage to the O2 sensors or result in gasket failure.

Function of Engine Oil

Engine oil is a vital component that contributes to the overall health of your vehicle’s engine. Its primary function is to provide lubrication, effectively reducing friction and dissipating heat caused by the combustion process and mechanical processes.

Engine Oil

Additionally, oil plays a crucial role in maintaining engine cleanliness by carrying microscopic deposits and debris to the filter, where they are captured and trapped.

Moreover, engine oil serves as a protective shield against corrosion. The combustion of the air-fuel mixture produces corrosive acids that can damage the metal components of the engine.

The oil acts as a barrier, slowing down the corrosive process and forming a protective layer on the cylinders, crankshafts, and pistons, safeguarding them from damage.

How to Repair an Oil Leak

Follow the below-given steps to repair the oil leak:

1) Find the Issue

Firstly, you need to identify the main cause of an oil leak. This process requires some investigation. Begin by examining the seals underneath the car.

Additionally, ensure that the oil pan plug is properly installed. In the case of old vehicle models, it is possible to encounter several oil leaks, leading to a more significant issue.

2) Use an Additive

Depending on the situation, an oil leak additive may offer a solution. The oil leak additives are designed to condition rubber seals, enhancing their flexibility and improving oil retention.

But it is important to note that these additives may require time to fully address the issue. It is advisable to use additives only if the leak is very small and time is a limiting factor. Nonetheless, it is suggested to follow proper repairs for the leaks.

In the case of an old vehicle model that may not be worth extensive investment, using an additive could be considered a last resort.

3) Consult Service Manual

Prior to beginning the oil leak repair, it is essential to consult your vehicle’s service manual. In some situations, you may discover that the repair is straightforward, and you can do it yourself.

However, there are cases where the complexity of the fix exceeds your capabilities, and it is advisable to seek assistance from a mechanic.

4) Get to Work

In case of uncomplicated repairs, you will only require a torque wrench, jack stands, a floor jack, and a few hand tools. Ensure that you have all the necessary tools before beginning the repair process.

When tightening the bolts, it is crucial to torque them according to the owner manual’s recommended specifications. Throughout the repair, refer to your service manual for guidance.

5) Test Drive the Vehicle

Once you believe the issue is resolved, you need to verify the repair by performing the test drive. Check the oil level and add more if necessary. Switch on the vehicle and open the hood. When your car is running, inspect your engine for any signs of oil leaks.

After driving for a brief period, you may move it a little and observe if any fresh oil gathers in the area where the repair was performed. If oil is present, it indicates that the leak persists and further attention is required.

Conversely, if no oil is detected, it is time to perform a test drive to ensure that everything is functioning correctly.

How Much Does an Oil Leak Repair Cost?

The average repair cost of an oil leak depends on the vehicle model and the size of the leak. The average cost of repairing an oil leak may vary significantly, ranging from $90 to $2,100.

By properly maintaining your engine and adhering to control oil changes, you can prevent yourself from an expensive repair. It is recommended to allocate a small amount of money towards this regular maintenance, as it can assist in preventing expensive engine repairs in the future.

Repair Estimated Costs 
Repairing an oil pan $90 to $520 
Repairing gasket damage $80 to $210 
Replacing a new oil filter $30 to $70 
Exchanging an oil drain plug gasket  $35 to $45 

FAQ Section

What is engine oil? 

Engine oil serves as a lubricant, reducing friction and keeping engine components moving smoothly. It also helps clean the engine by preventing contaminants buildup. Consult your vehicle’s service manual to determine the recommended oil change intervals.

How serious is an engine oil leak? 

Oil leaks can cause damage to your car’s cooling system, radiator, and engine, as well as harm the environment. Neglected leaks can lead to premature wear of rubber hoses and seals in these components. Moreover, oil leaks may also lead to fire and safety hazards.

How long will it take to fix an oil leak? 

Repairing an oil pan gasket typically takes 1 to 2 hours at a mechanic’s shop or around six hours if attempting a DIY fix.

Can I drive with an engine oil leak? 

Yes, you can drive, but it is not suggested to drive with an oil leak. Oil leaks can be dangerous and may lead to a fire. If left unaddressed, it can lead to early engine damage.

How long can you drive your car with an oil leak? 

It is not advisable to drive long distances with an oil leak. But, if necessary, it is generally safe to drive up to 10 miles before getting the leak fixed as soon as possible.

Can oil leak damage your engine?

Oil leaks can result in both reduced oil pressure and increased engine wear and tear. If you observe typical indications of an oil leak, like dark patches beneath your car or the oil light on the dashboard turning on, it’s essential to address the problem promptly. Delaying the necessary repairs can exacerbate the situation and lead to more significant complications.

What is the most common cause of oil leak?

The gasket is the most common cause of the oil leak.

How much does it cost to repair a Mercedes oil leak?

This cost varies according to the labor cost and the nature of the leak. The average cost to repair a Mercedes Benz oil leak is from $500 to $1000. 

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