Smells, Smoke & Leaks
How Do You Know Your Car Is Leaking Oil?
An oil leak is usually noticed in one of a few ways. You might spot dark brown or black puddles or spots on the ground where your car has been parked. You may notice a burning smell coming from the engine bay, especially after driving, as oil drips onto hot engine parts. In more serious cases, you might see blue or grey smoke coming from under the bonnet or from the exhaust.
Your oil warning light coming on while driving is another sign that oil levels may have dropped due to a leak. If this happens, you should stop the car as soon as it is safe to do so.
What Is Causing the Oil Leak?
There are many possible causes, ranging from minor to serious. Only a car diagnostics check can confirm exactly where the leak is coming from on your car.
Worn or Damaged Gaskets
Gaskets are seals that sit between two joined surfaces in the engine, such as the valve cover gasket or the sump gasket. Over time they harden, crack, or degrade, allowing oil to seep through. Gasket failure is one of the most common causes of oil leaks, particularly on older or high-mileage cars.
Loose or Damaged Oil Drain Plug
The oil drain plug sits at the bottom of the engine sump and is removed during an oil change. If it is not tightened correctly afterwards, or if the seal around it has worn, oil will leak from the bottom of the engine. This is usually a straightforward fix.
Worn Engine Oil Seals
Oil seals sit around rotating components such as the crankshaft and camshaft to stop oil escaping. These seals are made from rubber and harden over time, causing them to crack and leak. A worn rear main seal, for example, can cause oil to drip from the bottom of the engine near the gearbox.
Cracked or Damaged Oil Pan
The oil pan (also called the sump) sits underneath the engine and holds the engine oil. It can crack or become damaged if the car bottoms out on a kerb, speed bump, or road debris. Even a small crack can cause a slow but steady oil leak.
Loose or Faulty Oil Filter
The oil filter is replaced during a service and screws onto the engine. If it is not fitted correctly or the seal has failed, oil can leak from around the filter housing. This is another common cause of leaks following a recent oil change.
Valve Cover Gasket Failure
The valve cover sits on top of the engine and is sealed with a gasket. When this gasket deteriorates, oil leaks from the top of the engine and often drips down the sides. You may notice a burning smell as the oil makes contact with hot exhaust components.
Head Gasket Failure
A blown head gasket is a more serious cause of oil loss. The head gasket seals the engine block and cylinder head together. If it fails, oil and coolant can mix internally, or oil can leak externally from around the cylinder head. Signs include a milky, creamy substance on the oil filler cap and white smoke from the exhaust.
Smells, Smoke & Leaks
Is It Safe to Drive?
| What you are experiencing | Is it safe to drive? | What to do |
|---|---|---|
| Small spots on the ground, oil level still normal | Use caution | Get it inspected soon. Small leaks can worsen quickly. |
| Oil level dropping between top-ups | Not recommended | Book an inspection as soon as possible. |
| Oil warning light on while driving | Do not drive | Stop safely immediately. Low oil can destroy an engine within minutes. |
| Burning smell from the engine bay | Not recommended | Have it checked promptly. Oil dripping onto hot components is a fire risk. |
| Blue or grey smoke from the bonnet or exhaust | Do not drive | Stop safely and call us. This indicates oil burning on hot engine parts. |
| Large puddle of oil under the car | Do not drive | Significant oil loss. Do not start the engine. Call for recovery. |
Smells, Smoke & Leaks
What Should You Do?
1. Check your oil level. Use the dipstick to check whether your oil level is within the safe range. If it is low, top it up carefully using the correct oil grade for your car, but do not treat this as a fix. The cause of the leak still needs to be found.
2. Do not keep driving if the oil warning light is on. Running an engine with critically low oil causes metal parts to grind against each other without lubrication. This can cause irreversible engine damage within a very short time.
3. Look for where the oil is coming from. If it is safe to do so, have a look under the car and around the engine for obvious signs of oil. Dark staining, wet patches, or oil running down the engine block can help narrow down the source.
4. Call First Auto Centre. Give us a call on 020 4539 0131 and describe what you have noticed. Our team can advise you straight away and get your car booked in for an inspection at our East Ham garage. If the car is not safe to drive, we can arrange 24/7 breakdown recovery.
5. Get a proper diagnosis. Oil can travel along engine components before dripping, which means the leak may not be directly above where the oil appears. Our mechanics will carry out a thorough inspection using car diagnostics and a visual check to find exactly where the oil is escaping from.
Spotted an Oil Leak?
Let Us Take a Look.
Oil leaks rarely fix themselves and will almost always get worse over time. Bring your car to First Auto Centre in East Ham and our experienced team will track down the source, explain what needs to be done, and give you a straight, honest quote. If the car is not safe to drive, our 24/7 breakdown recovery service can bring it to us.
Call us on 020 4539 0131 or visit us at 1 Lawrence Road, East Ham, London, E6 1JN.
We are open Monday to Saturday, 09:00 to 18:00.
This page is for general guidance only. Only a physical inspection can properly identify the source of an oil leak. If your oil warning light is on, stop driving immediately and call us.
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No unnecessary repairs or hidden fees—just straightforward, honest assessments.
Your Questions
FAQs
A small amount of oil consumption between services is normal, particularly on older or higher-mileage engines. However, if you are needing to top up regularly or you can see oil on the ground, that goes beyond normal consumption and should be investigated.
Engine oil is usually dark brown or black, particularly if it has been in the engine for a while. Fresh oil can be a lighter amber colour. Oil stains on the ground are usually darker and feel slightly greasy. If you see a bright green or orange liquid, that is likely coolant rather than oil.
Stop-leak additives are available and can sometimes slow a minor leak temporarily, but they are not a proper fix. They do not address the underlying cause and can in some cases cause further issues. A proper repair is always the better option.
It can do. During an MOT test, a significant oil leak that is dripping from the vehicle or poses a risk of contamination can result in a failure. A minor seep may be noted as an advisory. Either way, an oil leak is worth fixing before your MOT is due.
Most cars need an oil change every 6,000 to 10,000 miles, or once a year, whichever comes first. This is carried out as part of a routine car service. Fresh oil also gives our mechanics the opportunity to spot any signs of leaks or seal deterioration before they worsen.
The cost depends entirely on where the leak is coming from. A loose drain plug or oil filter is a very minor fix. A gasket or seal replacement will cost more depending on which one has failed and how accessible it is. A head gasket repair is at the more expensive end. At First Auto Centre, we give you a clear, honest quote before any work begins.
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Contact Us
- info@firstautocentre.co.uk
- 1 Lawrence Road, Newham, London, E6 1JN
- Mon-Sat: 09:00 - 18:00
- Sunday: Closed
