Fuel injectors are like the heart of your engine; they determine its performance and health. But can I drive with a bad fuel injector?
If fuel injectors are faulty, you will experience rough idle, engine misfires, excess vibration from the engine, and higher fuel consumption. You may also smell fuel odor in the cabin when injectors are leaking.
Can you continue to drive your car when a fuel injector is malfunctioning? How do you know your fuel injector is bad?
How Do You Know Your Fuel Injector Is Bad?
It’s easy to notice faulty fuel injectors if you are a seasoned driver. Your machine will start behaving differently. Look out for the following signs:
You should pay attention to these obvious signs for your safety when driving.
1. Uneven Idling
Rough engine idle is one of the first signs of bad fuel injectors. That means there is an uneven supply of fuel to the engine to maintain constant RPM when idling.
The fluctuations in RPM cause rough idle. And in severe cases, the engine will stall when it no longer gets enough fuel from injectors.
2. Engine Misfiring
Engines require enough fuel injected to maintain RPM when you are driving. Since a bad injector may be clogged and cannot deliver the needed fuel on time, misfiring occurs. Misfiring causes a significant loss of engine power.
You may start feeling that your vehicle is sluggish and struggling to accelerate when stepping on the gas pedal. Acceleration can also get rough, what most people call jerking.
3. Excess Engine Vibrations
Engines are well balanced from the factory and produce minimal vibrations when running. But a bad injector will throw that balance off due to misfiring.
That results in excess vibrations and car shakes, which dominate your cabin and give you an uncomfortable ride. You will experience these vibrations on idle or acceleration.
4. Leaking Fuel
Fuel leaks may go unnoticed for some days if you are not the type to go under the hood before every trip. Fuel injectors suffer wear and tear over time.
At the same time, injector seals deteriorate. Fuel injector cracking due to old age is unavoidable. When that finally happens, gasoline will leak out.
When inspecting your vehicle, check fuel injectors and fuel rails for leaks. This is often associated with the gasoline odor in the cabin.
5. Reduced Fuel Efficiency
You will noticeably realize an increased fuel consumption. The engine will demand fuel injectors to supply extra, ideally not needed. You may also notice increased smoke from the exhaust, indicating incomplete fuel combustion.
What Causes Fuel Injector To Go Bad?
Your fuel injectors can wear out with age, but some factors can significantly lower their lifespans. The following are the possible causes of a bad fuel injector:
1. Low-Quality Gasoline
Low-quality fuel has large quantities of contaminants that easily clog or block fuel injectors. That causes less or no air-fuel mixture to get to the combustion cylinder, leading to engine misfiring.
2. Clogging By Fuel Residue
After you shut down your engine, fuel residues evaporate and deposit on the fuel injector nozzles. These deposits can accumulate and harden over time, especially if you like taking many short trips.
The fuel injector nozzles get blocked. That is not common when you take long trips because there is enough time to melt and wash the deposits away before they become a problem.
3. Electrical Component Failure
Fuel injectors depend on the magnetic power to pull up the pintle. This power comes from a solenoid controlled by an electrical circuit. If there is a short or open circuit, the entire fuel injector will fail to inject fuel.
4. Engine Blow-by Sludge
The engine blow-by consists of fuel and oil that get past the piston rings into the crankcase during the compression stage. A vehicle has a PCV system to take care of this mess. If this system fails, for whatever reason, the sludge may block fuel injectors.
5. Broken Or Leaking Fuel Injector
Fuel injectors can also fail over time. Cracking or seal breakage is not new to drivers and mechanics. So, before checking anything else, please start with the injectors themselves for any cracks that may leak fuel.
Can I Drive With A Bad Fuel Injector?
Yes. It is not recommended to drive your car with a bad fuel injector.
Your fuel injector can be dirty, stuck, or leaking. These faults have different severity levels. And since you cannot know how bad your fuel injectors are, don’t drive your car if you are not heading to an auto repair shop.
A dirty or clogged up fuel injector can still deliver a gaseous air-fuel mixture to the engine, but it won’t be enough to meet the demands. Your engine will start misfiring. That seems safe, but what if the injectors are stuck?
Whether fuel injectors are stuck closed or open, driving will cause severe damage to the engine; but if you are lucky, the engine stalls and fails to restart. But if you are unfortunate, you suffer costly engine damages.
Stuck open fuel injectors cause the cylinder to run lean and burn a hole in the cylinder or valve. On the other hand, stuck closed fuel injectors will damage the catalytic converter and significantly reduce fuel efficiency.
Leaking injectors pose more threat to your engine than any other injector fault. They will deliver fuel in liquid form instead of an air-rich gaseous mixture.
That can potentially cause a hydrostatic lock, which may bend or break valves and connecting rods if you continue to drive your car.
How Much To Replace A Bad Fuel Injector?
Fuel injectors will not last the entire lifespan of the car. Many are rated between 50,000 to 100,000 miles. But you can make them last longer before you replace them with regular cleaning.
Experts recommend cleaning your fuel injectors every 30,000 miles to avoid the buildup of contaminants that can block them. A professional fuel injector cleaning service costs about $50-$100. But if you are a DIYer, you can pay about $10-$15 for a bottle of cleaner to do at home.
Watch the short video below to learn how to clean dirty or clogged fuel injectors without using expensive equipment.
When fuel injectors finally need replacement, you should have a budget of around $600 to $1,250. You also need an additional $200 to $250 for labor.
However, these figures depend on your car model. Some can cost more than $2,000 to replace the fuel injectors. Using non-OEM parts can save you money, but you may not get the same reliability.
Fuel injectors are crucial components in your car. Always strive to keep them in good condition and act fast if they need your attention. Do not drive your vehicle around with a bad injector. It is more cost-effective to replace your fuel injectors than an entire engine block.
Always check for signs of bad injectors and fix them immediately. Look for engine misfires, excess vibration, rough idle, slow accelerations, and reduced fuel economy. Also, monitor your dashboard for the CHECK ENGINE warning light.
- How Do You Know If Your Fuel Injectors Are Clogged?
- How To Clean Fuel Injectors Without Removal
- If One Fuel Injector Is Bad, Should I Replace Them All?
- Does Running Out Of Gas Damage Fuel Injectors?
Tim Miller is an automotive mechanic and blogger from Denver, Colorado. I’m the founder of obdadvisor.com, an automotive blog about OBD2 scan tools. My fan page is facebook.com/autozikcom. I’ve had over 20 years of experience in car repair and using OBD scanners. My reviews and articles about car repair and maintenance can be found on my own websites.