Is your car jerking, shaking, or making strange noises when you hit the gas? That’s called sputtering, and it’s a sign that your engine isn’t running right.
While it may feel like a big problem, you can often fix a sputtering car with a few simple steps.
This guide breaks down each part of the process so you can understand what’s wrong and how to fix it—even if you’re not a mechanic.
Step 1: Understand Why Your Car Sputters
Let’s start with the basics. A sputtering engine usually means there’s a problem with how the engine is getting fuel, air, or spark.
Your car’s engine needs three things to run smoothly:
- Air (comes in through the air filter)
- Fuel (pumped in from the gas tank)
- Spark (from the spark plugs)
If any one of those parts doesn’t work right, the engine can’t do its job. That’s when you feel jerking or hear popping sounds—especially when accelerating.
Common causes of sputtering include:
- Dirty air filters
- Bad spark plugs
- Blocked fuel injectors
- Weak fuel pump
- Leaky vacuum hoses
- Faulty sensors (like the mass airflow sensor)
- A clogged catalytic converter
Each of these can mess with how your car runs, especially when you need extra power to speed up.
Step 2: Start Simple – Check the Air Filter
The air filter keeps dirt, bugs, and debris from getting into the engine. But over time, it gets clogged. If your engine can’t get enough air, it will sputter and feel weak when you hit the gas.
How to check it:
- Open the hood of your car.
- Find the air filter box (usually near the front or side of the engine).
- Pop it open and remove the filter.
What to look for: If the filter is covered in dirt, leaves, or looks black, it’s time to replace it.
The fix: You can buy a new filter for $10–$30 and install it in under 5 minutes.
Step 3: Inspect the Spark Plugs
Spark plugs fire tiny sparks that help your engine burn fuel. When they go bad, the engine can misfire, causing that sputtering sound and jerking feeling.
How to inspect them:
- Locate the spark plugs (usually on the top or side of the engine).
- Use a spark plug socket to remove one at a time.
- Check the tips—if they’re black, oily, or look burnt, replace them.
The fix: Spark plugs are cheap ($5–$15 each). Always replace all of them at once for best results.
Bonus tip: If your car has over 80,000 miles and you’ve never changed the spark plugs, this could be your main problem.
Step 4: Clean the Fuel Injectors
Fuel injectors spray gasoline into your engine in a fine mist. If they get clogged, the fuel doesn’t flow right, which causes poor performance and—you guessed it—sputtering.
Easy fix: Use a fuel injector cleaner.
- Buy a bottle from any auto store.
- Pour it into your gas tank.
- Drive normally and let it clean the system.
Deep cleaning: If the simple cleaner doesn’t help, a mechanic can remove the injectors for a full cleaning or replacement.
Step 5: Check the Fuel Pump
The fuel pump is like your car’s heart. It pumps gas from the tank to the engine. If it’s weak or dying, you’ll feel sputtering, especially when driving uphill or at high speeds.
Warning signs:
- Engine sputters above 30-40 mph
- Car struggles to start
- Whining noise near the fuel tank (usually under the back seats)
What to do:
- Turn the key (without starting the engine) and listen for a quiet buzz near the rear of the car.
- If you hear nothing or the car struggles to stay running, the fuel pump may need replacing.
The fix: Replacing a fuel pump is a bigger job, usually done by a mechanic. It costs $300–$800.
Step 6: Look for Vacuum Leaks
Vacuum hoses help control air flow and pressure inside your engine. If one cracks or falls off, it can throw everything out of balance. That leads to sputtering and rough idling.
How to find leaks:
- With the engine running, listen for a high-pitched hissing sound.
- Look at the rubber hoses around the engine. Check for cracks or loose ends.
The fix:
- Replace cracked hoses with new rubber ones (cheap and available at auto parts stores).
- Reattach any that came loose.
Bonus method: Spray soapy water on the hoses. If you see bubbles while the engine is running, there’s a leak.
Step 7: Clean the Mass Airflow Sensor (MAF)
The MAF sensor tells your engine how much air is coming in. If it’s dirty, your engine might send too much or too little fuel, causing poor acceleration and sputtering.
How to clean it:
- Locate the MAF sensor between the air filter and the engine.
- Carefully unplug and remove it.
- Spray it with MAF cleaner (don’t use regular cleaners!).
- Let it dry and put it back in.
Important: Don’t touch the sensor wire inside—it’s very delicate.
Step 8: Inspect the Catalytic Converter
This part helps clean the air coming out of your exhaust. But if it’s clogged, your engine can’t get rid of waste gases. That pressure builds up and makes your car sputter or even stall.
Signs of a bad catalytic converter:
- Rotten egg smell from the exhaust
- Decreased power when driving
- Check engine light is on
What to do: A mechanic can check the flow using special tools. If it’s clogged, it must be replaced. This is often a costly repair, so check all the simpler stuff first.
Step 9: Scan for Error Codes
Today’s cars come with onboard computers that store trouble codes when something goes wrong. You can scan these codes and get a better idea of what’s causing the sputtering.
How to do it:
- Get an OBD-II scanner (or ask your local parts store to check for free).
- Plug it into the port under the dashboard (usually below the steering wheel).
- Turn the key to “on” (but don’t start the engine).
- Read the codes and look them up online or ask a pro for help.
Examples:
- P0300 = Random misfire
- P0171 = Engine running too lean (too much air, not enough fuel)
- P0420 = Catalytic converter problem
Step 10: Know When to Call a Mechanic
You can fix many sputtering problems yourself, especially with the steps above. But some issues—like a failing fuel pump or a broken sensor—are harder to handle at home.
Call a mechanic if:
- The check engine light is flashing
- You’ve tried the basic fixes and it’s still sputtering
- Your car stalls or won’t start
- The engine makes loud knocking sounds
It’s better to pay for a small repair now than wait and risk a bigger problem later.
Final Thoughts
A sputtering engine doesn’t mean your car is ruined—it just needs some attention. Start with the basics: air filter, spark plugs, and fuel system.
Move on to sensors and more complex parts if needed.
