Diagnose Car Surges e-CAR
Car Surges
What does it mean when we say a Car Surges?
Car surging is when your engine unexpectedly revs up or down without pressing the accelerator. This erratic behaviour can be unsettling and might point to underlying mechanical issues. Let’s break down the most common reasons for car surging and how to fix them.
Most Common Causes of Car Surging
Fuel System Issues:
Dirty fuel injectors: Clogged injectors can cause uneven fuel delivery, making the engine surge. |
Fuel pump problems: A weak or failing fuel pump may cause inconsistent fuel pressure. |
Faulty fuel pressure regulator: If the regulator malfunctions, it can cause fuel pressure spikes or drops. |
Air Intake and Sensors:
Vacuum leaks: Leaks in the intake system allow unmeasured air into the engine, affecting the air-fuel mixture. |
Dirty or faulty mass airflow sensor (MAF): This sensor measures air intake — if it’s dirty or malfunctioning, the engine may rev irregularly. |
Throttle body issues: Carbon buildup in the throttle body can disrupt airflow, causing surging. |
Ignition System:
Faulty spark plugs or coils: Misfiring due to worn spark plugs or coils can cause erratic RPM changes. |
Ignition timing problems: Incorrect timing can affect engine performance and cause surging. |

Electronic and Sensor Problems:
Faulty engine control unit (ECU): A glitchy ECU may send the wrong signals to fuel injectors or ignition coils. |
Idle air control valve (IACV): If stuck or malfunctioning, this valve can cause inconsistent idling and surging. |

Transmission and Drivetrain
Torque converter issues: In automatic cars, a faulty torque converter can cause engine speed to fluctuate. |
Clutch slipping (manual cars): A slipping clutch may cause sudden rev changes. |
How to Fix Car Surging
Diagnostics Check: Use an OBD2 scanner to identify any error codes.
Clean Fuel Injectors: Ensure smooth fuel delivery by regularly cleaning the injectors.
Inspect Air Intake: Check for vacuum leaks or a dirty throttle body.
Test Ignition System: Replace worn spark plugs or faulty coils.
Examine Sensors: Ensure the MAF sensor and IACV are clean and functional.
Transmission Inspection: Get your torque converter or clutch checked by a professional.
find a workshop near you

Don’t Let Car Surging Catch You Off Guard!
If your car is surging, it’s best to address the issue early before it leads to bigger (and costlier) problems. At e-CAR, our expert mechanics offer top-notch diagnostics and repairs to keep your car running smoothly.
Explore our services
Car service
Car repairs
Repairs for all car makes and models with genuine parts.
Fleet Maintenance
Service a fleet of cars or trucks with a fast turnaround time.
Truck Services
Professional servicing tailored to trucks and heavy-duty vehicles.
Car Accessories
Upgrade your car with premium car accessories.
Approvals & accreditations
Trust
e-CAR is accredited with RMI, MIWA approvals, and Right 2 Repair Supporter in SA for top-quality vehicle servicing and workmanship that meets industry standards.