Why is My Car Leaking Oil When Parked?

Is your car leaking oil when parked? If so, you’re probably wondering where the leak is coming from, what’s causing it, and how to get it fixed. In this article, we’ll explain why your car is leaking oil when it’s parked, along with some tips to help you identify, fix, and prevent oil leaks.

In This Guide:

Why is your parked car leaking oil?
How to identify if your parked car is leaking oil
What to do if you notice a leak when your car is parked
Tips to prevent oil leaks
Conclusion
FAQs

Why is your parked car leaking oil?

Car engines need oil to remain lubricated. If there’s not enough oil because of a leak, your engine and its supporting components will wear down faster. This can lead to engine failures and other mechanical issues that are not only costly to repair but potentially dangerous.

Here are four of the main causes to investigate.

Damaged oil pan or oil filter

Your oil pan and oil filter are located underneath your car at the bottom of the engine, making them highly susceptible to damage. Road debris, knocks from speed bumps, and rough driving can all puncture steel oil pans or crack aluminium pans, causing oil to seep out.

Oil filters can become loose or damaged, which can also cause oil leaks.

Faulty gaskets or seals

Your car’s engine gaskets and seals are exposed to severe temperature changes, pressure, and the elements every time you drive your car. This can wear them down over time, causing damage and oil leaks. Some of the main gaskets or seals that could be at fault are:

Valve cover gasket: A valve cover gasket sits between your vehicle’s engine and the valve cover at the top of your cylinder head, sealing oil inside the engine. Cracks can form due to constant high heat, age, and physical damage.
Oil pan drain plug: If your oil pan drain plug is loose or damaged, you might spot used oil leaking from your car. A leaky drain plug can either be re-threaded or replaced, depending on the extent of the damage.
Oil pan gasket: Along with being subjected to high temperatures and excessive pressure, steel oil pan gaskets are susceptible to rust. This creates tiny holes through which oil can leak out.

Degraded crankshaft and camshaft seals

Crankshaft and camshaft seals are designed to prevent splashing oil from escaping the engine and leaking onto other car parts or outside of your vehicle.

Not only are crankshaft and camshaft seals constantly moving — putting them at high risk of wearing out over time — but they also have to withstand extreme heat, oil pressure, and vibration, which can lead to damage.

Your rear crankshaft seal — also known as your rear main seal — is especially prone to causing oil leakage when your car is parked and idling.

Getting worn crankshaft and camshaft seals replaced by a trained mechanic is crucial to prevent significant engine damage. Compare car repair quotes to find the best deal.

Loose or damaged filler cap

A loosely fitted filler cap will cause oil to splash out of the oil fill hole, leaking onto other vehicle components. Damaged threads and O-rings can also cause leaks, as they prevent the cap from fully sealing. These are relatively simple issues that you may be able to diagnose and fix yourself.

How to identify if your parked car is leaking oil

A car leaking oil when parked will usually leave behind very clear evidence. The most obvious signs are:

Puddles of oil under your car: If it’s a greasy black, brown, or amber puddle, it’s likely to be an oil leak.
Dashboard lights: If the oil light on your dashboard lights up, it might suggest that you’re losing oil due to a leak.
A burning oil smell: Oil doesn’t just leak onto the ground. It can seep over other hot engine components, causing a bitter burning smell when starting or driving your car.
Oily engine components: Are parts of your vehicle oily? You may have an oil leak somewhere in your vehicle.

What to do if you notice a leak when your car is parked

So, you’ve noticed that your car is leaking oil when parked — what next? Here are the key steps you should take:

Identify where the oil leak is coming from: The best way to do this is to look underneath your car — grab a torch — and note which part of your vehicle the leak is coming from.
Assess whether you can fix the leak or consult a mechanic: If you only have a minor leak, you might be able to fix it yourself. Loose oil filler caps or oil drain plugs are easy to tighten and replace. But if you have a severe leak (or if you can’t find the source of the leak), contact a professional.
Check your oil levels: Before driving your car to a garage, check your oil levels to make sure that the leak hasn’t drained it past safe driving levels.
Notify your car insurance provider: If your oil leak occurs as the direct result of a collision or incident, your car insurance provider may cover the cost if you have a comprehensive car insurance policy. So, it’s worth notifying your provider to check.

Tips to prevent oil leaks

Engine oil leaks are a common problem, but they can be avoided if you take the right steps.

Regularly check your oil levels: Not all leaks are immediately obvious. If your oil levels are depleting when your car is parked, it could be a sign that you have a leak, even if there’s no visible oil underneath your vehicle.
Use the right type of oil: Putting the wrong type of oil into your vehicle rapidly degrades seals, gaskets, and other components, increasing the likelihood of leaks. Consult your user manual to identify the type, quality, and viscosity of oil that you should be using.
Perform regular maintenance: Regularly inspect gaskets, seals, and other components for signs of wear or damage. For a more thorough inspection, take your car to a garage for routine check-ups every year.

Conclusion

If you’ve spotted a puddle of oil under your car, there’s no need to panic. Most engine oil leakages have obvious causes that can be quickly diagnosed and resolved by a professional mechanic — or even by yourself, if it’s a minor leak. Just make sure to get leaks checked out to minimise engine damage and prevent failure.

FAQs

Is it safe to drive with an oil leak?

Driving with an engine oil leak presents all kinds of risks — severe engine damage, engine failure, fire hazards, and road safety issues. So, unless the leak is minor, you should avoid driving your car.

Can I fix an oil leak myself?

Replacing a valve cover gasket or tightening loose filler caps and oil drain plugs are relatively DIY-friendly fixes, provided the components are easily accessible. However, if the leak is severe or caused by more complex issues, such as a faulty crankshaft or camshaft seal, it’s best to consult a trained mechanic.

How much does it cost to fix an oil leak?

Oil leak repair costs vary depending on the complexity of the underlying cause and the severity of the leak. A minor leak caused by a simple issue can cost as little as £150, whereas a leak caused by a complex issue may cost upwards of £700.