If you think your car is leaking oil when parked, this needs to be inspected and fixed by a professional mechanic as soon as possible.

Read on and find out what to when your car is leaking oil, and how to prevent future leaks. 

 

Signs Your Car Is Leaking Oil

If you notice any of the following warning signs - either when parked or whilst driving - you may have an engine oil leak. 

 

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Oil & Filter Change

 

Blue Smoke Coming from Your Exhaust Pipe

Both an external and internal oil leak will cause blue smoke to come from your exhaust.

As the engine gets hot whilst the car is running, an oil drip onto the engine will cause the dark blue smoke which you may see from your exhaust.

 

Smell of Burning Oil

You may smell burning oil after parking your car.

This may mean that oil has leaked or is leaking onto the hot engine.

You should pull over immediately and leave your car if you ever notice a burning smell while driving.

 

An Overheating Engine

The vehicle’s engine can overheat because of an oil leak, especially if the oil is low.

Engines need oil for their parts to stay lubricated while running.

A lack of oil will cause the engine will start overheating when there is inadequate lubrication.

 

Car Leaking Oil When Parked After an Oil Change

If you notice an oil leak under your car, then this could be related to a recent oil change. 

It could be that the oil filter might not have been properly put back in place, or it may be damaged.

Another possibility is a loose or broken oil filler cap.

The drain plugs or gaskets might have been left loose or over-tightened, or you may have a problem with your rear main seal.

A leak may be a sign that your car needs to undergo an oil change.

The vehicle may have shielding underneath that stops the oil from dripping onto the ground by containing it.

You won't be able to see the oil dripping, and this can hide a major oil leak.

A low oil level indicator may be a warning signal for such vehicles.

An oil-stained engine should be examined for leakages.

A mechanic will be able to determine the source of the fluid leak for you. 

 

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BookMyGarage branded infographic about the warning signs of a car leaking oil and how to spot them

These are some signs that your car may be leaking oil.

 

Is Your Car Leaking Oil or Another Type of Fluid?

If you suspect that your car is leaking oil, you will need to rule out the possibility that the fluid is something else.

Since your car uses many different types of fluids and lubrications, it can be easy to mistake one fluid for another.

To check whether your car is leaking oil when parked, you should inspect the colour of the fluid.

 

Black or Light Brown

Black or light brown fluid is usually engine oil. 

Clear

A clear fluid is likely water draining from your vehicle's air con system.

Red or Reddish Brown

Red or reddish brown fluid is typically transmisssion fluid or power steering fluid leaking

Transparent Yellow or Brown

Transparent yellow or brown liquid is usually brake fluid

Bright Green, Blue, Pink or Orange

A bright green, blue, pink or orange fluid is likely to be a coolant leak.

 

Why Is My Car Leaking Oil?

There are several reasons why your car may begin to leak oil.

 

Degraded Engine Gaskets

Engine gasket degradation can occur because of the heat generated from driving.

The temperatures of the engine block and the head rise when you stop your vehicle.

This makes the metal parts stretch, resulting in increased pressure on the gaskets.

A reduction in engine temperature will make metal components contract, creating gaps between them and the seals.

The gaskets will suffer wear because of this, and this could result in an oil leak.

Take the car to a garage to ensure that there isn't a problem with the head gasket.

The head gasket can blow if it is old or the rubber around the engine block deterioriates. 

These two components would have to be replaced for the problem to be fixed.

 

Head Gasket

The head gasket is a vital part of the internal combustion process.

It can blow if the seal between the engine block and cylinder head wears away.

 

damaged head gasket oil seal, stylised view of damaged engine part

 

Damaged Oil Pan

Your car's oil pan, located at the bottom of the engine, can be destroyed by rough roads or debris.

The pan's gasket also sustains damage or gets worn out over time.

All these can lead to oil pan or oil pan gasket leaks.

 

stylised view of a damaged oil pan causing a leak underneath a car

 

Bad Oil Seals

Your car could be leaking oil when parked as a result of a faulty valve seal, but you won't see the oil if the gaskets have no holes.

The combustion process will burn the oil up.

 

broken oil seal as a result of leaking oil, circular wheel with several layers with a tear in the outermost layer

 

Incorrect Installations

A wrong oil gasket installation can cause a leak to occur.

The valve cover gasket or oil pan gasket can be over-tightened. Uneven distribution of tightness may also be a factor.

Loose or incorrectly attached oil filters can cause the engine oil flowing through them to leak.

 

stylised view looking into damaged oil pan, causing a leak.

 

 

How to Prevent a Future Oil Leak

To prevent an oil leak from occuring in the future, there are a few things you can do. 

You should never ignore car problems for long, as all your vehicle's parts are interconnected. 

The fault of one part will affect the others, and procrastinating will only put additional strain on other vital components and increase your repair bill. 

You should also have your oil replace regularly so that a mechanic can examine the engine and any parts that utilise oil. 

Scheduling regular car services and repairing and replacing old parts at the appropriate intervals can also help you to minimise the likelihood of leaks. 

 

How Often Should I Change My Oil?

It can be difficult to know when your oil needs changing, due to its black colour.

The best thing to do is consult your vehicle’s owner manual and see what the manufacturer recommends.

Each model will have its own recommendation and following it will elongate your car’s lifespan.

There is no need to have it changed any more times than what your manufacturer recommends.

Some drivers get their oil changed every 6 months, but for a more accurate number to rely on, turn to your mileage counter.

Older models will need an oil change around every 3,500 miles, whereas some newer cars can get up to 10,000 miles out of their oil before it needs a change.

Be sure to follow your manufacturer’s advice when it comes to oil changes.

 

A trained mechanic will know exactly where to start and what to do if you suspect your car is leaking oil.

Whether your car needs a simple oil change or a larger job like an oil pump replacement, taking your car to a qualified mechanic is the best way to ensure your car gets the care it needs.

 

FAQs

Are Small Oil Leaks Normal?

Can You Drive a Car with an Oil Leak?

How Much Does an Oil Leak Repair Cost?

 

You can read more of Tim's articles on his website, OBD Advisor.