Motors hot after tuning in Betaflight: causes and fixes
Motors run hot after a tune when they work hard on noise or oscillation. The usual cause is D-term amplifying high-frequency noise that the filters don’t remove, or D set too high for the filtering you have. Land, let the motors cool, and fly a short hover test. Then add D-term filtering or lower D first, check the gyro filtering next and confirm the RPM filter is on.
Why do my motors get hot after tuning?
Motors heat up when the flight controller keeps asking them to change speed very fast. They can’t follow a noisy signal, but they still burn power trying.
- D-term amplifying noise. D reacts to how fast the gyro changes, so noise at high frequency turns into large, rapid motor commands. More D means more of it.
- Too little filtering. Higher cutoffs or fewer notches let that noise through. If you raised cutoffs to sharpen the quad, that can be the cause.
- Too much D. Even with decent filters, a high D can push noise through.
- Oscillation. If P or D is too high, the quad can oscillate at a fixed frequency. The motors then work hard all flight and heat up fast.
- Mechanical problems. See below. Fix these first, because tuning can’t.
How do you tell warm from hot?
Warm is fine. Hot is a warning. A simple touch test is enough. Disarm and unplug the battery first, and let the props stop completely.
- Warm: you can hold your finger on the bell for several seconds. Normal after a hard flight.
- Hot: you pull your finger away quickly, or it feels uncomfortable to hold. Do not keep flying. Change something first.
Motors also differ from each other. One motor much hotter than the other three points to a mechanical fault more than to a tune.
How do you check safely?
Run the same short test after every change.
- Props on, battery fully charged and the quad in an open area.
- Arm, hover about 20 seconds, then land.
- Disarm, wait about a minute, then touch each motor.
- If any is hot, don’t fly more. Make the next change.
A short test means the worst you risk is a warm motor, not a burnt one. Fly only a short hover first after any filter or D change. If the quad oscillates or you hear it getting rough, land immediately.
What should you change first?
Change one thing at a time, in this order. Make small steps and test after each one.
- Confirm the RPM filter is on if your ESCs support it. See RPM filter setup. It removes motor noise that otherwise reaches D.
- More D-term filtering or less D. Lower the D-term lowpass cutoffs or move the D-term filter slider down. D-term lowpass 1 is dynamic by default, between
dterm_lpf1_dyn_min_hz(75 Hz) anddterm_lpf1_dyn_max_hz(150 Hz), and D-term lowpass 2 isdterm_lpf2_static_hz(150 Hz). Or reduce D, base and peak, by about 10%. Reduce D if you run high D and the filters already look sensible. In 2025.12 and newer the base D isd_rollandd_pitchand the peak isd_max_rollandd_max_pitch. Up to 4.5 the base isd_min_rollandd_min_pitchand the peak isd_rollandd_pitch. Use the setting-name converter if you move between versions. - Then gyro filtering. Lower the gyro lowpass cutoffs or the gyro filter slider in small steps. Don’t put gyro lowpass 1 below 100 Hz, because the extra delay makes the quad worse.
- Look at the log. Fly a throttle sweep and read the spectrum, using the filter tuning guide. A peak rising with throttle points to motor noise. A fixed peak points to frame resonance.
Don’t raise D and reduce filtering in the same step. More filtering adds delay, so you may need to trade some sharpness for cooler motors.
When is it mechanical?
Fix these first, because no setting can cure them:
- bent or damaged props;
- loose motor or frame screws, or a loose stack;
- worn or rough motor bearings.
If one motor is hotter than the others, or the quad is noisy in a way that doesn’t change when you change filters, check these before touching tuning values.
Symptom, cause and fix
| Symptom | Likely cause | What to change |
|---|---|---|
| All four motors hot, quad looks calm | D amplifying noise, too little filtering | Lower D-term lowpass cutoffs, or lower D, in small steps |
| Hot, with a noise ridge rising with throttle | Motor noise not filtered | Turn on the RPM filter, or add dynamic notches |
| Hot, with a fixed-frequency peak | Frame resonance | Add a notch or lower the gyro or D-term lowpass |
| Hot after raising filter sliders | Filtering too light | Move the filter sliders back down |
| Hot and the quad oscillates | P or D too high | Lower D, then P |
| One motor hotter than the others | Bent prop, loose screw or bearing | Fix the hardware first |
| Cool motors but slow, soft response | Too much filtering | Raise cutoffs in small steps |
How FPV PID Tune handles it
You tell the app how warm the motors ran. If they ran hot, it only allows more filtering or less D, and the Sharper feel is disabled. Warm motors keep any reduction in filtering to a small step. Every value passes a validator with fixed safety limits and is read back after Apply, and one-click Undo is always there. The how it works page shows the whole flow.