When your car engine sputters, it’s evident that something isn’t functioning right.
You’ll feel sporadic power and the relative change in noise. The car will most likely feel like it’s lurching or otherwise struggling.
Before continuing to read through this guide I made for you, check you have adequate fuel. You could have an issue with the fuel gauge.
If that all seems acceptable – perhaps you filled up only a few days ago? – there’s something more significant at play.
So, what can be done about that? How can you best repair a defective car, and why is it crucial?
Let’s begin! I’ll start with the main causes.
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What Causes A Car Engine To Sputter?
A sputter could have its original cause in a number of components.
In brief, the power isn’t being generated by the engine smoothly. The issue could also lie in your transmission, which is, of course, connected.
Your internal combustion engine mixes air (oxygen) and fuel (gasoline or diesel). The spark plug ignites this, creating a forceful explosion that drives a piston downward.
Through connecting rods (con rods), this reciprocal motion is converted into rotary force. It then passes through the transmission for gearing and finally turns the wheels.
Sputtering could be caused by anything abnormal in this system. However, the most frequent problems will be fuel, air, or sensor related.
Here are a few of the most prevalent. Problems with the…
- Fuel pump
- Fuel filter
- Fuel injector
- Spark plug
- Throttle body – dirt can prevent airflow at idle
- Mass Air Flow (MAF) sensor
- Vacuum leak
- Catalytic converter blockage or oxygen sensor failure
- EGR valve clogged
If the issue lies with one of these (and it most likely does), you’d expect the component to be only partially damaged, dirty, obstructed, etc.
Some of the time, it works efficiently. The rest of the time, it doesn’t. That’s what leads to this sporadic low power, or “sputtering.”
This article examines your problem by symptom. However, any of the signs listed below could be caused by any of the above.
A qualified and dependable car mechanic should perform all diagnosis and repair work.
Car Engine Sputters While Driving Along And Idling
If your car’s engine won’t stop sputtering, the issue probably lies with the fuel system or MAF sensor.
The sputtering sensation is an abrupt change in power produced by the engine. It feels like it’s lurching because it’s generating a lot of energy and then not much. This cycle repeats.
That’s the reason why the fuel system is exceptionally likely to be the cause. The air intake system has limited space for such significant changes.
That being said, it never hurts to examine the following:
- Throttle body and plate
- TPS
- MAF sensor (more on that below)
The fuel system, though, has plenty of areas where the gas flow might be intermittent. It passes through the following:
- Pump
- Lines
- Filter
- Injectors
Obstructions or pressure reductions in these regions hinder the liquid/vapors. Consequently, some cylinders might receive excessive fuel while others receive none at all.
This is, in essence, a type of misfire. Have a mechanic check the entire system meticulously.
The MAF sensor is responsible for telling the ECU how much air (“load”) is entering. The computer then sends a matching amount of fuel to the injectors.
If the MAF reading is too high or low, the ECU will send too much or not enough gasoline to the cylinder. This creates a rich or lean mixture (more or less power than needed). If the readings fluctuate constantly, you’ll get that lurching, sputtering feeling.
In rare cases, the problem could lie with the control module itself. You could have an automotive electrical engineer check out the ECM (Engine Control Module).
Car Idles Fine But Sputters When Accelerating
If your car’s tick-over is steady, but the sputtering starts when you put your foot down, you should check the throttle position sensor (TPS).
The TPS might be blocked or damaged. Since you don’t touch the pedal when your car’s idling, it will have no impact at this stage.
Once you accelerate, though, the readings are sent to the ECU from the TPS. This then determines how much fuel to inject into the combustion chamber.
Abnormal TPS readings might lead to intermittent amounts of gasoline entering the engine.
Have your transmission fluid and the TCM (Transmission Control Module) inspected if the TPS appears satisfactory.
Like the TPS, the transmission has little to do with when your car is stationary. Once you begin moving, it kicks into action.
Issues with the transmission might appear as an irregular sensation.
After this, you should have a more thorough check done on the fuel system and for any misfires (spark plugs, ignition coils, etc.). In most cases, you’ll find this affects your vehicle at idle, too. Still, particular issues might only become apparent when accelerating.
Car Sputters When Starting And Idling
If your car sputters while you’re stopped, the engine is struggling to maintain its idle speed. This is known as tick-over. It’s approaching stalling at idle.
The most likely cause here is an issue with the idle air control actuator, fuel system, or a general misfire. The MAF sensor could also be dirty or damaged, or the EGR valve could be extremely clogged.
A quick cleaning of your throttle body might solve the issue. If not, a technician will have to inspect your engine more closely.
Afterwards, they will pinpoint the issue and provide you with an assessment. If you have resolved the throttle body problem, you will most likely be charged for the ensuing repairs:
- Spark plugs
- Ignition coils
- EGR valve cleaning
- Fuel filter or pump
- MAF sensor
Car Sputters When Starting
If your car sputters when starting but then runs flawlessly, there is most likely an issue with the starting system.
When you turn the key, the battery connects to the starter motor. This rotates the flywheel on the crankshaft and means the engine can begin functioning under its own power.
Most typical misfires will manifest themselves during starting and running. The only distinctions during the starting procedure are:
- The engaged starter motor (powered by the 12-Volt car battery)
- A rich fuel mixture to help with starting
The issue is likely battery related. If it isn’t, inspect the starter motor and the rest of the starting system. Finally, search for common misfire symptoms that might be minor enough to be masked when the engine is running.
Conclusion: What To Do About A Sputtering Car
The main point to take away? If your car’s sputtering, it’s stumbling. Go straight to a mechanic.
These things don’t fix themselves. The quicker you take action, the faster your car will be repaired and the less it’ll cost!
A sputtering engine will likely cost a few hundred dollars, including labor and assessment. The final total will, of course, depend on what work needs doing.
Leaving it without inspection or repair could lead to serious engine damage. Don’t take the risk.
