There are 2 owner-reported engine complaints for the 2003 Volvo S40in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Engine light stays on. I have had 2 mechanics check it out. They don't know why the light is on. I am very concerned about the fuel line problem.
I WAS DRIVING WHEN THE CAR START TO ACCELERATED BY ITSELF, ACCEL PEDAL WENT TO THE FLOOR. I COULD NOT KEEP A CAR EVEN BY THE HAND BRAKE, SO AS IT WAS JUMPING AHEAD. THEN THE CAR BEGAN TO BLOW BLACK AND WHITE SMOKE OUT UNDER THE HOOD. SOME HOW I TURN OFF THE ENGINE, TOOK THE KEY AND RUN AWAY FROM THE CAR IN THE MIDDLE OF THE TRAFFIC ROAD. GREEN LIQUID UNDER THE CAR. IT DIED ON THE ROAD. POLICE CAME, THE CAR TOWED. AFTER SEVERAL DAYS OF CHECKOUT : T/3.8 CHECKOUT AND REPLACED T-STAT, TEMP SENSOR, T-STAT HOUSING GASKET; BG COOLANT FLUSH ; PCV; ENGINE VENT; ENGINE MECHANICAL; BG POWER STEERING; BG BRAKE AFTER A WEEK I GOT THE SAME--JUMPING, NOT STABLE, ACCEL PEDAL GOES TO THE FLOOR. INTERNAL SHORT IN CYL 3 AND 2 COIL AND FOULED SPARKPLUGS T/1.5 REPLACED COIL PACK FOR CYL 3 AND 2 AND REPLACED SPARKPLUGS. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026