Car leaking? How to identify liquid dripping from your car and what to do

Car leaking? How to identify liquid dripping from your car and what to do
Have you ever walked up to your car and noticed there’s a mystery puddle underneath it? It’s a worrying sight.

But what are these leaks? And are they a real cause for concern? 

Find out how to identify what’s dripping under your car, whether it’s dangerous, and what to do about it.

My car is leaking fluid – what should I do?

Liquid dripping from your car can be alarming, but it isn’t necessarily a cause for concern.  

Firstly, make sure the leak is actually coming from your car. If there’s a puddle beneath your car and you’ve parked in a car park or on the street, the liquid could be from another vehicle. 

To check whether it’s from yours, take a torch and have a look under the car to see if there’s signs of leakage. This could be a telltale shine or trail left on a component under your car.

Next, you need to determine where the leak is coming from and what’s actually leaking. The easiest way to do that is to slide some white cardboard underneath the car while it’s parked up so it can capture the drips.

This’ll give you a good idea of what liquid is actually leaking – and how concerned you should be. 

My car’s leaking clear liquid

If your car is leaking a clear, water-like liquid it’s probably just that: water. 

A clear liquid could also be coolant, although this will likely have a coloured tinge to it (green, blue or yellow) and will have an odour, unlike water. See below for more information on leaking coolant. 

Car leaking water – what to do

It’s unlikely you need to do anything. Usually, leaking water is simply condensation from the aircon unit – surprisingly common during summer – or the exhaust, which is more common in winter.

Another typical cause is your windscreen washers, but again this is unlikely to be a major issue and you can probably just ignore it.

However, if you can’t identify the cause or there’s more than just a little water leaking from your vehicle, you might want to check that the clear fluid actually is water and that there isn’t a more serious issue.

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My car’s leaking amber/multicoloured liquid



If you see a brownish puddle under your car that looks multicoloured when the light hits it just right - you’re probably leaking petrol or diesel.

Petrol and diesel both have very strong, distinctive scents. If you can smell something that reminds you of a petrol station, feel confident that you’ve identified your mystery puddle.

You’ll see these spills most commonly around forecourts due to careless pumping, but if they show up when you’ve parked up elsewhere, it shouldn’t be ignored.

Car leaking fuel - what to do

Avoid driving if you can - fuel is highly flammable and a spark in the wrong place could set it alight. Your fuel economy could be taking a serious hit as well!

Fuel leaks usually occur because there’s a crack or hole in the fuel tank somewhere. As long as the fuel tank isn’t rusting away due to age, any good mechanic will be able to patch this up without having to replace the whole thing.

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My car’s leaking red fluid



Red might just be the scariest colour of any liquid to find leaking from under your car, and it usually means you have a transmission fluid leak on your hands. 

You’ll know it’s transmission fluid if there’s red fluid leaking in the middle or front of your vehicle – and it’s not only bad news for your driveway (it can stain), but it can be bad news for your car, too.

Car leaking transmission fluid – what to do

Firstly, avoid driving if you think you’ve sprung a transmission fluid leak as your car may not run properly – putting yourself and others in danger – and use could cause further damage.

There are a number of causes of these leaks – from broken seals and cracked fluid lines to failing gaskets and general wear and tear – and the issue should be looked at as soon as possible.

You can check the fluid levels using the dipstick (see your owner’s manual for more information on where this is), but you’ll probably need to have your car towed to your nearest garage where a professional can take a look at it. 

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My car’s leaking brown/black fluid

A puddle of amber, brown or black liquid under your car is probably engine oil, but if you want to be sure get close enough to touch it. If it feels slick and it’s hard to get off your fingers, it’s almost certainly oil.

Car leaking oil – what to do

First, try and locate the leak. It should be fairly easy to spot once you’re under the bonnet, and if the leak is from something like a valve cover gasket you may feel confident enough to fix it yourself.

If you do decide to fix it or continue driving with a small oil leak, make sure your oil tank is always filled to the appropriate level. Failing to do so could lead to lasting (and expensive) damage to your engine.

If you can’t fix the leak yourself or it’s more than just a few drips, you’ll want to check it into a local garage and let a mechanic take a look. This will help prevent the leak cause any lasting damage to your car.

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My car’s leaking red/brown fluid

A reddish-brown liquid leaking near the power steering reservoir could be power steering fluid. Unlike motor oil or transmission fluid, this’ll have a slightly sweet, burnt smell to it. 

If there’s a leak, it could be a sign there’s a problem with the hoses and tubing that carry the fluid from the pump to the steering rack, such as a loose connection or a crack. 

Car leaking power steering fluid – what to do

Firstly, check the fluid levels to see how serious the leak has become and how low you’re running.  

Although there’s nothing physically stopping you from driving with a power steering fluid leak, any sustained driving on low levels could quickly cause lasting damage so should be avoided at all costs. 

If the leak is from an easy-to-fix loose connection you can probably sort it yourself, but for anything more serious have a mechanic look at the hose and connecting parts as they may require replacing. 

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My car’s leaking a green/yellow fluid



Coolant comes in a whole host of different colours these days, meaning that if you see your car leaking green, yellow, pink, blue, red, or even clear liquid you might be facing a coolant leak. 

This might make it sound tricky to identify, but thankfully coolant has a distinctively sweet smell – think candyfloss – and an almost slimy texture, which’ll help you differentiate it from water if your coolant happens to be clear. 

Car leaking coolant – what to do

Coolant, which helps maintain the vehicle’s temperature, can leak from pretty much anywhere as there are so many coolant hoses in and around the engine. But the most common leak is from your radiator.

If your coolant’s leaking, your engine could be at risk from overheating so you need to make sure you get it seen to quickly, in order to avoid any lasting damage.

If the leak is small – from a leaky radiator cap or loose connection, you might be able to fix it yourself. However, if it’s a cracked reservoir or something else unfixable you’ll need to check it into a garage to avoid being caught out on the road.

My car’s leaking a brown fluid

The most serious leak you can have on your car is brake fluid, and if you spot a slippery, brownish liquid leaking from your vehicle you could have a problem that needs a quick response.

You’ll spot this fluid under the wheels and around the brakes in general. While brake fluid leaks are rare, if you encounter one in can be extremely dangerous.

Car leaking brake fluid – what to do

Leaking brake fluid is a huge problem because without it you won’t be able to safely control your car. So if you spot a leak don’t even try to drive your car, as you may not be able to stop.

Instead, you should find your local garage right away and get towed to a mechanic where they’ll be able to check your car over and provide the best option for fixing the brake fluid leak. If the leak happens at home, you can even call out a mobile mechanic to come to you.

Should I take my car to a garage?

If you encounter a leak that you can’t easily fix yourself, you’ll need to check your vehicle into a garage to get it seen to. 

To help you find a mechanic you can trust for any repairs that you might need, the RAC Approved Garage Network only includes garages that provide quality work and exceptional customer service, giving you peace of mind if your car needs attention. Check out the rest of our car care section for servicing, MOTs and more.

The best way to stay ahead of car issues before they develop is to get it looked at by an expert regularly. You can keep on track with your car's maintenance and save money by getting a Service and MOT Plan to spread the cost over two years.

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