What Causes an Oil Pan Leak & How to Spot One?

Worried about that puzzling oil puddle beneath your car?
It might be an oil pan leak.

But how can you tell for sure?

Don’t worry!
We’ll dive into the causes and telltale signs of an oil pan leak. We’ll also discuss its severity, repair costs, and more.

Let’s jump right in!

This Article Contains:

What Causes an Oil Pan Leak?
6 Fool-Proof Signs of an Oil Pan Leak
How Serious Is an Oil Pan Leak?
How to Diagnose and Fix an Oil Pan Leak
How Much Does it Cost to Repair an Oil Pan Leak?
What Are the Other Sources of an Oil Leak?
How to Prevent Oil Pan Leaks in the Future

What Causes an Oil Pan Leak?

An oil pan is made of aluminum or stamped steel and forms a tight seal with the engine base through an oil pan gasket. It stores the motor oil (engine oil) that keeps a running engine lubricated. It also has a drain plug screwed into it that helps with the oil change process.

But why would it start leaking oil?
Here are five common causes behind a leaking oil pan:

1. Damaged Oil Pan

The engine oil pan can develop a crack or a hole from debris impact encountered on the road while driving. It can also leak due to a worn drain plug, which can happen over frequent screwing and unscrewing during any oil change.

2. Worn Oil Pan Gasket

An oil pan gasket leak is often the leading cause of car leaking oil. The pan gasket sits between the engine block and the oil pan, acting as a seal.

An oil pan seal can develop cracks over time due to frequent temperature-related expansions and contractions in the adjoining metal components. This can result in oil leaks.

3. Improperly Tightened Parts

An oil leak can result from a loose pan bolt holding the oil pan in place, an ill-fitted oil filter housing, or a loose drain plug after an oil change.

4. Improper Gasket Installation

Using an inadequate sealant or a liquid gasket (like silicone RTV and Right Stuff) that isn’t recommended by the oil gasket manufacturer can result in an oil pan gasket leak.

5. Contaminated Contact Surface

Oil, grime, and particles deposited on the surfaces of the engine block and the oil pan prevent the pan gasket from forming a tight seal. This results in a leaking oil pan gasket.

Now that you know the reasons behind a car leaking oil, let’s explore the symptoms.

6 Fool-Proof Signs of an Oil Pan Leak

Here are some common indicators of a leaking oil pan:

1. Oil Puddle or Stains Under the Car

If you have significant oil leakage, you may notice a puddle of black or brown liquid under your parked car. However, a small leak may result in a less noticeable oil stain, so it’s good practice to pay attention to any unexpected dripping under your vehicle.

2. Oil-Coated Undercarriage

A severe oil pan gasket leak can result in the oil getting blown backward along a moving vehicle’s undercarriage.

3. Illuminated Oil Light

The low oil level warning light will show up in your car’s instrument panel when you have a substantial oil loss. This is especially alarming if you’ve recently refilled fresh oil.

4. Low Oil Level

If you have a lit warning light, you can do a quick dipstick test to confirm a low oil level. If the reading is low, especially if you recently had an oil change, it could indicate an oil pan leak.

5. Smoke or Burning Oil Smell from the Engine

An oil pan gasket leak may let engine oil trickle to the heated exhaust manifold and pipe, which burns instantly and releases smoke.

Likewise, a strong odor of burning oil is a good indicator of a car leaking oil.

6. Engine Overheating

If your motor has lost a lot of engine oil, it’ll result in overheating due to inadequate lubrication. If ignored, this can lead to irreversible engine damage.

Having learned about the symptoms of an oil pan leak, let’s see if you can take a chance to drive with it.

How Serious Is an Oil Pan Leak?

Oil loss results in a low engine oil level and low oil pressure, which increases frictional wear and can cause irreversible engine damage. This makes it a moderate-to-serious issue that can quickly progress into a troubling problem.

Moreover, engine oil is flammable and can catch fire upon coming in contact with hot engine and exhaust parts. It can also damage sensors, rubber hoses, and seals designed to be used in an oil-free environment.

What if you’re already on the road?

If you have no option but to drive with a leaking oil pan, keep an eye on the engine’s oil level and get the problem fixed ASAP. It also helps to carry along some extra motor oil and a fire extinguisher for emergency use.

Alternatively, you could use a stop-leak engine oil additive to fix a gasket leak. But remember, these additives provide a temporary oil leak repair solution, and you’ll eventually need to get the pan gasket replaced.

Now, how do we get to the actual source of the leak?

How to Diagnose and Fix an Oil Pan Leak

It’s important to correctly diagnose the source of leakage before it can be fixed, lest the oil leak repair expenses and efforts get wasted. That’s why it’s best left to an auto repair mechanic. They’ll have a better understanding and the right tools to identify the issue.

Let’s check out how they would go about fixing a leak.

A. Diagnosing an Oil Leak

Here’s what a mechanic would do:

Use jack stands to raise the car.
Clean the undercarriage using brake parts cleaner and water and let it dry.
Spray the suspected oil leakage sites with white foot powder.
Turn on the engine.
Use a source of bright light to look for any signs of an oil leak on the sprayed undercarriage.

B. Fixing an Oil Leak

They’ll begin by checking if each oil pan bolt and the oil drain plug are tightened as per the manufacturer’s specifications.

If they find that the leak demands something more than tightening a loose drain plug or pan bolt, here’s what they’ll do:

Park the vehicle on a level surface and raise it using jack stands.
Disconnect the cable at the battery’s negative terminal.
Remove the drain plug to let the engine oil drain.
Gain access to the oil pan by removing the required components.
Remove the oil pan bolt, gasket, and oil pan.
Clean the engine and pan contact surfaces with a solvent to ensure a perfect seal.
Replace the leaking oil pan gasket or the oil pan.
Place the bolts into their respective positions and tighten them using a torque wrench.
Screw the oil drain plug back into the pan and tighten it using a torque wrench.
Lower the vehicle to the ground.
Refill the engine with fresh oil (new oil).
Reconnect the cable to the battery’s negative terminal.
Start the engine and check for oil leaks.

Note: A mechanic would also check the drain plug and its gasket for signs of wear and replace them if necessary.

So, what kind of repair costs can you expect for this fix?

How Much Does it Cost to Repair an Oil Pan Leak?

Here are estimates for repairing an oil pan leak, depending on the issue:

Oil pan gasket: Around $450 and $600. This includes the new gasket, which ranges from $300 to $400, and the labor charges, varying from $120 to $140.

Oil pan with drain plug: Around $300 to $1000

However, labor costs can vary across vehicles depending on the ease of accessibility to the oil pan.

But what if the leak isn’t from the oil pan?

What Are the Other Sources of an Oil Leak?

It’s easy to misinterpret the cause of an oil leak, given the multiple sources that it can arise from, including a worn camshaft seal or damaged head gasket. So, it’s possible your engine oil leak may not be due to an oil pan issue.

Here are four other common sources for oil leaks:

1. Oil Filter

Oil can leak if the filter is not installed correctly in the oil filter housing or if the oil filter gasket is damaged.

2. Oil Pump

Inside the upper oil pan, the gasket attaching the oil pump to the engine block may get worn, causing an oil leak and low engine oil pressure.

3. Valve Cover

The valve cover is sealed against the cylinder head using a cover gasket. Loose bolts on a valve cover or a worn valve cover gasket (rocker cover gasket) may lead to an engine oil leak.

4. Rear Main Seal

Also called crankshaft seal, this seal is located on the rear side of the engine where the crankshaft connects to the transmission. It prevents the motor oil from leaking from the crankshaft. If the rear main seal fails, it can lead to oil loss.

Is there anything you can do to avoid leaks?

How to Prevent Oil Pan Leaks in the Future

Whether you drive a Honda Motor Company car, a BMW, or a Ford, here are some ways to minimize the risk of oil pan leaks:

1. Get oil changes at recommended intervals: Old, dirty oil can contribute to the deterioration of seals and gaskets, increasing the likelihood of leaks. Regular fluid and oil filter changes help keep the engine and its components in good condition.

2. Schedule professional inspections: Have a mechanic inspect your vehicle periodically to identify potential issues before they become serious problems.

3. Opt for high-quality or OEM parts: OEM parts are designed for your vehicle and generally offer better fit and durability compared to generic alternatives. Likewise, invest in a high-quality oil pan seal that can withstand heat and pressure.

4. Drive carefully: Be mindful of road conditions and avoid driving over debris, potholes, or rough terrain whenever possible.

5. Regularly check your vehicle’s oil level: Consistent low oil levels can indicate a leak. Detecting a small leak can prevent more significant issues.

6. Learn basic maintenance: Educate yourself on DIY vehicle maintenance tasks, such as checking oil levels and identifying common signs of leaks. Being knowledgeable allows you to address minor issues before they escalate.

Get Oil Pan Leaks Fixed with AutoNation Mobile Service

A leaking oil pan may be fixed by tightening a loose bolt, or you may require a gasket or pan replacement. While you can tend to the former yourself, the latter is best left to a qualified professional.

Want an easy and accessible automotive repair solution?
AutoNation Mobile Service can help you out!

We are a mobile auto service solution available seven days a week.