How Do I Know If My Fuel Injectors Are Leaking?

Diagnosing why my fuel injectors are failing

You should know that the engine compartment of your vehicle is one of the most important parts of the vehicle.

Therefore, you need to ensure that all of the working parts are in appropriate condition to avoid any complications while driving the vehicle.

One such component is the fuel injectors that may be affected with damages that cause leaking. The biggest question, therefore, is “How do I know if my fuel injectors are leaking?”

You can always check for leaking from your fuel injectors by yourself even before you contact a mechanic or vehicle expert.

You can do this by checking for any of the following signs:

1. Unusual Reaction From The Vehicle When You Start It-Hard Starts
2. Poor Fuel Economy
3. Violent Idling From The Vehicle
4. Surging Of The Engine
5. You Can Smell Fuel Odours When You Are Close Or Even In The Vehicle
6. The Emissions From The Exhaust Pipe Of The Vehicle Are Quite Poor
7. Thinning Of The Oil In The Vehicle
8. Cases Of Hydro-Lock
9. The Check Engine Light Is On

If your vehicle is experiencing fuel leakage from the injectors, this might be a time bomb as wildfires are likely to occur.

This may not only be harmful to you as the vehicle owner but will cause serious damage to the engine which will be quite costly to repair.

Therefore, you need to look out for the above signs and take the most appropriate action to avoid the consequences.

9 Symptoms Of Bad Fuel Injectors: Ways To Find If Yours Faulty

1. Unusual Reaction From The Vehicle When You Start It-Hard Starts

A fuel injector that is leaking is not able to allow enough fuel to the engine of the vehicle. This makes it almost impossible for the engine to start.

It may take too much effort to start the vehicle or it won’t start at all. Similarly, you might realize that the vehicle misfires just as you are trying to accelerate while driving the vehicle.

Misfiring is caused when the fuel injectors are unable to provide adequate fuel to the engine of the vehicle that is needed for it to speed up when you step on the gas pedal.

If you notice either case of poor starts or misfiring, it is recommendable that you check out the fuel injector’s condition and correct that to avoid the overheating of the engine.

2. Poor Fuel Economy

This is quite an obvious sign that would need you to check throughout the whole system that fuel runs through.

The issue might just be that the fuel injector is leaking and thus you will have to refill the fuel tank more than you did previously-because most of it would be lost through the leakages.

3. Violent Idling From The Vehicle

For your vehicle to idle smoothly, the fuel injectors need to provide a consistent amount of fuel to the engine.

If not, its RPM will drop and get below the optimal level required and this will cause the irregular idling from the vehicle, which will be rough.

4. Surging Of The Engine

If the fuel injectors in some way let through excessive fuel into the engine cylinder, you might notice surging of the engine of the vehicle.

This will have serious consequences in the experience you get from your vehicle.

For instance, the vehicle might not have a smooth reaction when you try to accelerate it-it will instead accelerate quite slowly than it did before.

You might also realize that the RPM reading from the engine will not be as it normally was.

It instead gets altered to a significant extent for constant loads instead of maintaining a constant RPM all through when you are driving the vehicle.

5. You Can Smell Fuel Odours When You Are Close Or Even In The Vehicle

If gasoline passes through the fuel injectors and does not get to the engine for combustion, you will be able to smell it.

You should be able to detect this if you are in the vehicle and you smell the odour of gasoline which might be quite abnormal.

Your immediate intervention to correct this will help you avoid dealing with serious damages that the leaking fuel injectors might cause later on.

6. The Emissions From The Exhaust Pipe Of The Vehicle Are Quite Poor

When you take your vehicle for an emission test and it fails the test, then one component that needs to be checked is the fuel injector.

The fuel injectors might have holes or even damaged seals that cause fuel leakages.

This causes incomplete combustion of the fuel or even that the fuel burns unevenly.

What causes this is that the leaking of the fuel injector causes a high likelihood of the fuel and air mixture to be fairly rich.

This will then cause damage to the catalytic converter of the vehicle through burning it entirely.

7. Thinning Of The Oil In The Vehicle

When fuel leaks, it can find its way and through to the intake valves and get in them when they are in the open position.

It gets past the rings and might mix with the engine oil and this causes cases of oil thinning. The consequences of oil thinning are quite severe and can be a handful to deal with.

For instance, the thinning of the oil might cause damage to the bearing and also scorching of the sidewalls of the cylinders through which engine oil passes through.

8. Cases Of Hydro-Lock

Leakages in fuel injectors can also cause hydro-lock which is the last damage that you might want to deal with as a vehicle owner.

When the fuel leaks, it accumulates above the piston which leads to locking of the engine since it is not able to compress the liquid which is found in the cylinder.

Hydralock is a severe beginning of damage on the working components of the vehicle-it leads to a bending of the rods, breaking of pistons and also leads to the head gaskets blowing out.

9. The Check Engine Light Is On

A digital way of knowing that your fuel injectors and also other components associated with your vehicle’s engine are through the check engine light.

It can detect damage to the fuel injector such as leakages and also dirty fuel injectors.

In this case, you should not be sure that the fuel injectors are leaking but the best step to take is to consult a mechanic who would check all the associated components and provide a lasting solution.


Leaking fuel injectors force you to deal with serious consequences if you don’t correct them in due time.

Leakages might be as a result of getting worn out due to old age which causes them to develop small holes on their parts and also on the seals of the fuel injectors.

The most common result of a leaking fuel injector is that it pauses as a fire hazard that will cause serious levels of damage to the vehicle and also other passengers in the vehicle.

Early intervention through checking out for the above signs will help to avoid dealing with any of the damages that might be caused later on.


1. Injector RX –


Written by Kane Dan

What happens when a fuel pump goes out while driving

How To Start A Car With A Bad Fuel Pump

Where are my fuel injector located? I'll need to remove them

How To Replace Fuel Injectors In Your Car