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RC car troubleshooting
By Paul Walsh Last reviewed
When an RC car stops working, the cause is usually simple. Work through the checks in order and you'll find most faults in minutes.
Start here
- Car battery charged and plugged in properly.
- Transmitter batteries fresh.
- Switch on in the right order: transmitter first, then car.
- Binding: if the car doesn't respond at all, rebind using the manual.
- ESC mode: set for the battery type you're using (LiPo or NiMH).
Fault finder
| Symptom | Likely causes | What to check |
|---|---|---|
| Nothing responds | Flat battery, not bound, switch, ESC fault | Batteries, binding, ESC lights |
| Steers but won't drive | Stripped spur, loose pinion, motor wire, ESC cut-off | Gears, pinion grub screw, wiring |
| Drives but won't steer | Servo failure, stripped servo gears, servo saver | Servo and linkage |
| Glitching or twitching | Weak transmitter batteries, aerial damage, servo | Batteries, aerial, servo |
| Stops after a few minutes | Low-voltage cut-off, overheating | Battery setting, temperatures, gearing |
| Grinding noise | Stripped spur or pinion, worn bearing, diff | Gears, bearings |
| Slow and weak | Tired battery, worn brushed motor, dragging drivetrain | Battery, motor, spin wheels by hand |
| Pulls to one side | Steering trim, bent parts, uneven tyres | Trim, arms, tyres |
| Motor very hot | Gearing too tall, dragging drivetrain, wrong motor for the car | Pinion size, free spin |
| Won't go in reverse | ESC mode, or reverse needs a double tap | ESC manual |
Steering problems
Check the servo moves smoothly and centres. A buzzing or jittering servo may have stripped gears or be overloaded; see RC servos explained. A stronger, faster servo is one of the most worthwhile RC car upgrades.
Overheating
Touch-test the motor and ESC after a few minutes' running: warm is fine, too hot to hold for a few seconds is not. Fix overheating by gearing down (smaller pinion), freeing up a dragging drivetrain, or using a motor suited to the car. Brushless conversions are especially prone to this; see brushed vs brushless RC cars.
After a crash
Check suspension arms, hinge pins, driveshafts, the steering linkage and wheel hexes. Bent parts cause pulling, binding and wear elsewhere.
Regular checks prevent most of these faults; see RC car maintenance. Back to the RC cars hub.
Frequently asked questions
Why won't my RC car move but the steering works?
Usually a stripped spur gear, a loose pinion, a disconnected motor wire, or an ESC that has shut down from low voltage or overheating.
Why does my RC car glitch or twitch?
Low transmitter batteries, a damaged receiver aerial, interference, or a failing servo. Start with fresh transmitter batteries.
Why does my RC car stop after a few minutes?
The ESC's low-voltage cut-off or thermal protection. Check the battery type setting and whether the motor or ESC is overheating.
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