10 Common Causes of Motorcycle Engine Oil Leaks

1. Engine Oil Leaks

Leaking motorcycle engine oil can be dangerous since it could catch fire If you see your motorcycle's engine leaking oil, it could be due to several reasons. Whatever the reason, an engine leaking oil is a cause for concern and should be fixed as soon as possible. Ignoring a leak could lead to several engine problems. You need to check the engine oil leak to identify the problem.

Let's learn about the most common causes of engine oil leaks!

2. 10 Common Causes of Motorcycle Engine Oil Leaks

Engine oil lubricates your motorcycle’s moving parts, reducing friction and loss of power to ensure the engine runs efficiently. However, if a motorcycle part is broken or faulty, the engine oil will start to leak out. Listed below are the motorcycle parts where engine oil leaks occur.

2.1 Seal/Gasket

Seals or gaskets become weaker with time, especially on motorcycles with higher mileage. The main gaskets that tend to leak oil are the valve cover, cylinder head, oil pan, and crankcase gaskets. If the pressure in the seal increases, this could cause oil leakage or engine failure.

2.2 Oil Filters

Oil leaks in the oil filter are a common occurrence. Oil filters can be worn out due to constantly removing dirt, particles, or other contaminants. A loose seal in the oil filters can cause engine oil to leak out. To help keep oil filters in good condition, make sure to change out the oil every once in a while. Older oil tends to have mixed residue that could contribute to damaged oil filters.

2.3 Piston Rings

Piston rings seal the combustion chamber and prevent oil from leaking into the cylinder. However, they will become worn out due to overuse, resulting in engine oil leaking from them.

2.4 Engine Block

A cracked engine block can also result in oil leaks. Cracks in the engine block are caused by overheating. Intense heat can cause stress that can weaken the integrity of the engine block. As more cracks form along the sides of the engine block, more places there are for oil to leak out.

2.5 Oil Plugs

Faulty oil plugs are another cause of oil leaks. The oil plugs that often suffer from oil leaks are valve cover plugs, oil drain pans, and side crankcase plugs. The reason oil plugs suffer from oil leaks is due to not being tight enough and vibrations causing them to come loose. Oil drain plugs can become damaged if the motorcycle’s bottom scrapes against a curb or a speed bump. Crankcase and valve cover plugs can also become looser or worn out over time. O-rings on the plugs can become brittle like gaskets, making them easier to break and allowing oil to escape.

2.6 Oil Pan

Oil pans are responsible for keeping the engine cool. They are affixed at the bottom of the crankcase to serve as an oil reservoir. The area between the engine block and oil pan can become worn down throughout a motorcycle's lifespan which can cause engine oil to leak through the weakened structure.

2.7 Hoses & Tubes

Hoses and tubes help siphon oil into the engine. If the hose has punctures or becomes worn out, it should be easy to spot where the oil leaks are.

2.8 Crankshaft Seal/Shift Shaft Seal

If a crankshaft or shift shaft seal becomes dried out, then the surface can become more susceptible to cracking, causing an oil leak.

2.9 Engine Oil

Pouring in too much engine oil can cause the excess amount to spill out of the air box.

2.10 Filler Cap

The oil filler cap covers the opening in the engine where you pour in engine oil. The pressure inside the engine has a direct impact on the pressure exerted on the oil filler cap. A loose, broken, or missing oil cap will result in oil leaking from the opening.

3. How to Fix Oil Leaks in a Motorcycle Engine?

If you find oil leaks in the engine, plan to make repairs as soon as possible. A small leak can grow and spread if left unattended for too long. It is best to fix the oil leaks early rather than wait for them to become worse.

3.1 Best Way to Fix Motorcycle Engine Oil Leaks (2023)

If you want to fix an oil leak in the motorcycle engine, apply the following steps:

Clean the engine
Locate the leak
Do an inspection

When looking for engine oil leaks, try to figure out which part is the cause of the problem. Replace the defective part and continue conducting regular maintenance checks of your vehicle.

4. Are Motorcycle Oil Leaks in the Gaskets Serious?

Yes, motorcycle oil leaks in the gasket leak are very serious. Gaskets contain the oil and keep it from leaking out of the engine.

Worn-out gaskets are more susceptible to damage, resulting in oil leaking. Any cracks in the gaskets can expose the engine’s interior to dirt, debris, and pollutants that could severely damage the engine.

5. What is the Reason for Oil Leaking from the Oil Cap?

Due to the high pressure inside the engine, a worn, damaged, or loose cap will cause oil to leak from the opening. Keeping the oil covered will prevent it from being contaminated.

6.What Causes Coolant to Travel Through the Exhaust and Into the Oil Pan?

Coolant helps keep the engine cool and prevents it from overheating.However, coolant cannot travel where it is supposed to if the motorcycle has any of the following:

Blown Head Gasket
Cracked HeadGasket
Cracked Engine Block

Damage to these parts can result in coolant entering the cylinder. White clouds pouring out of the tailpipe is a sign that coolant has gotten mixed into the engine oil.

7. What Causes Oil to Blow by the Dipstick?

Too much pressure applied to the crankcase can cause oil to blow by the dipstick. This process is referred to as “blow-by,” which occurs during combustion.

7.1 If the Oil Dipstick Isn't Lowered, Will You Lose Oil?

Yes, a dipstick that is not lowered will result in the loss of oil. This is due to the high pressure inside the engine.

8. FAQs

8.1 Is it normal for a motorcycle to leak oil?

Oil leaks are normal in old motorcycles. It can also occur in new motorcycles due to severe damage. With time, the body parts of the motorcycle started to get damaged. Due to these worn-out motorcycle parts (that can be in several parts), there is an oil leak. Mainly the oil leak starts from the engine of the motorcycle.

8.2 Can a leaking oil pan cause the engine to overheat?

Yes, any sort of oil leak can cause the engine to overheat. Without lubrication, the pistons start to generate heat as they rub against each other.

9. Conclusion

Never leave your bike dormant. People don't understand that leaving a motorcycle without using it for days causes a negative impact on the parts of the engine. Here we have explained the common causes that will help you in finding the right cause of an oil leak. Find it out and save your motorcycle! If you wish to improve its appearance, you can add new Saddlebags, seats, crash bars, fairings, handlebars, luggage racks, and sissy bars.