How to Identify and Diagnose Common Oil Leak Problems

One of the worst things that can happen is having an oil leak in your car and truck and not even notice it. Sometimes oil leaks are so small, unless you notice a spot on your driveway you may not even know you have a problem until you check the dipstick and realize you’re two quarts low! Even small leaks can lead to a host of problems, the most severe being literally blowing your engine. Yes, it really can happen!

Having even a small oil leak can damage even the toughest of cars and trucks. What some people don’t realize is the amount of oil in your car is specifically engineered to be just enough to lubricate all of the engine’s internal parts while keeping the pressure of the system at levels that don’t cause your seals or rings to blow out. So even too much can cause major problems.

And that’s not even addressing the environmental damage that leaking oil causes as it washes away into storm drains or seeps into the earth poisoning everything it touches.

This also includes any wildlife unlucky enough to come into contact with the contaminated water, or worse drink some of it and die a miserable slow death. And this can happen to pets just as easily right in the middle of suburbia.

And this scenario is for only one car, imagine the millions countrywide and the negative environmental impact they are having!

So when you notice even the smallest of leaks, you really need to address the problem as quickly as possible. Not just for your own car’s sake, but for everyone else who will be affected by the oil that’s entering the environment.

Common Causes of Oil Leaks

There are any number of reasons your car may be leaking oil. And sometimes it isn’t all that easy to spot the problem, especially if it’s underneath your car or the undercarriage has a bunch of gunk on it already making it almost impossible to see where the original leak is coming from. So we wrote this article to assist you in spotting where the most common leaks come from:

Worn Gaskets and Seals – Gaskets and seals are usually made from non-metallic products or thinner metal than the rest of the engine parts, so they tend to wear out a lot faster than any other engine part. Or they shrink or become brittle with age and start to leak since the gaskets sit between gaps in the metal parts and prevent leaks. But once damaged or brittle, they can easily sprout leaks. So this is usually the first place to look for an oil leak!

Deteriorated Hoses – Again, since most hoses are made from rubber or plastic, they tend to break, get brittle or shrink over time due to all the use and heat your engine throws out. You can easily see how well they are holding up by just bending them a little and seeing if they show cracks or are no longer smooth to the eye. If that’s the case, it’s usually easier to just replace them rather than use an additive.

Cracked Engine Block – Seeing your engine works on combustion under immense amounts of heat and pressure, it’s easy to see why sometimes engines simply crack or literally explode under heavy use. If your motor is cracked, it will definitely leak oil or coolant and it should be easy to spot where it’s coming from. If you do have a cracked block or even head, you must get it to your mechanic’s shop as there is little a stop leak additive can do.

Oil Pan Damage – Another common cause of leaks is a pin hole in the oil pan, or your gaskets are shot. Your oil pan is under the motor and it’s what holds all of the oil that’s not being circulated inside the engine. Sometimes it’s even possible to hit the oil pan on a speed bump or a rock in the road loosing the seals or even piercing the pan. Luckily an oil pan problem is usually an easier fix and shouldn’t cost too much.

Valve Cover Gasket Leak – Another very common cause of oil leaks is your valve covers. Most often the gaskets are to blame and this usually happens on older cars. These sit on top of the engine and are attached to the heads where the pistons are. Leaks are usually easy to spot.

Improperly Installed or Faulty Oil Filters – I’ve had this happen, so it is something to look for! I had an oil change at one of those speedy oil chain stores and they didn’t put the oil filter on tight enough. In a week I was super low on oil and luckily they did replace the oil filter and changed my oil again for free. But look, because it does happen. The oil filter is on the bottom of the oil pan and looks like a fat coca cola aluminum can.

As you can see, there are a lot of places your car can start spouting oil from. Pinning down exactly where the leak is will make your life a lot easier. And sometimes the leak isn’t even a big deal and can be fixed easy enough.

How to Identify an Oil Leak

Sometimes an oil leak isn’t all that noticeable and you really need to dig around to find where the source is. This all becomes even more complicated if you don’t happen to be ‘mechanically inclined’ and have no idea where things are. But even a non-mechanic can diagnose some issues with just a bit of knowledge. Here are some ways to identify an oil leak:

  • Burning Oil Smell – When you smell burning oil, you’ll know it. The smell is very distinct from smells that normally waft up from your car and if you happen to smell it and see smoke, then you’re about guaranteed there’s an oil leak somewhere. And if the smell gets stronger while you’re driving or when the engine is hot, you should really take it to your mechanic to find out how bad it really is.
  • Low Oil Levels – If you’re keeping up with regular oil changes yet you notice the oil is always running low, then you probably have a leak somewhere. The problem is people don’t realize even low oil can begin to negatively impact an engine due to the lack of pressure low oil causes. So even low oil can be really bad, so take it as seriously as any other engine problem!
  • Leaking Fluids – One of the easiest ways to spot anything leaking from your car is to park it on a clean driveway or somewhere similar. If you move the car and there are fluids on the once clean surface, you know you have some sort of leak. And this little tip can be used for anything from oil to engine coolant. It’s always smart to test this every month or two just to be safe.
    You can usually tell by the color of the fluid to know what’s leaking. Brown or black is oil, green is coolant and blue is power steering fluid. But to be sure, ask someone that really understands cars.
  • Unusual Noises – Since oil leaks prevent your internal engine parts from being lubricated correctly, sometimes you might hear noises, usually the ticking noises coming from your lifters. This means your oil is way too low and you need to add some right away, leak or no leak!
  • Warning Lights – Most cars are equipped with oil lights that signal you’re running low on oil. If your light keeps coming on, check your oil manually using the dipstick. If your dipstick reads you do have enough oil, then you may have a short in your electrical system.
    So there are a few common ways to tell if you have an actual oil leak, it’s just about diagnosing the problem and maybe getting your hands, or driveway a little dirty. Just be patient and observant and you’ll eventually find the cause of your missing oil.

How to Diagnose an Oil Leak

Now that you understand the basic common causes of oil leaks and how to identify them, the whole problem shouldn’t be so challenging. Just be sure you take the time to search for your leak. And as a wrap up, here’s the process of diagnosing an oil leak:

Inspect the Engine – Take a real close look at the engine from angles, including from underneath the engine. It’s really helpful if your motor is clean for a visual inspection and isn’t caked with a bunch of crud and burnt oil all over it. If you need to, you can even bring your car to a car wash and power wash the engine, just let it cool off before doing this or you can crack the engine block!

Perform a Pressure Test – Pressure tests are quite accurate and can tell you quickly what sort of shape your oil system is in. Plus if there is a leak, the added pressure will make it really stand out in case it wasn’t possible to see the leak otherwise. It involves hooking up an air pump with a gauge and adding pressure to the system, the tools can easily pinpoint exactly where and how bad the leak is. If the air pressure begins to go down, you know there’s a leak. If it holds, then there isn’t.

Seek Professional Help – If you’ve read all of this and still don’t have the faintest clue on what you’re doing, it may be time to get a professional mechanic to look at the problem. Everyone has things they’re good at, and things they don’t quite grasp. That’s why people have jobs doing what they are good at. So if you really need the help, then get it before you have a bigger problem on your hands!


Identifying and diagnosing common oil leak problems yourself can really go a long way as far as saving you some money at the shop. And we’ve gone over everything you could need to know to do it yourself. And you should at least try, you may find it’s something small and can be taken care of easily, or you might just save your engine from blowing up!

But if after reading all the information here you still don’t feel comfortable doing things yourself, don’t feel bad. Not everyone is mechanically inclined. Just bit the bullet and take it to a shop that can test your system and figure out what’s going on. You don’t necessarily need to get it fixed right then, but at least you’ll know what the problem is once and for all.


As a user of The Automotive Men (, please note that we participate in the Amazon Associates Program. This means that “As an Amazon Associate, I earn from qualifying purchases.” We are not directly sponsored or endorsed by Amazon, but our website may contain affiliate links that provide us with a commission when you make a purchase through them. Thank you