Symptom
Revs flare between gear changes
The engine speed jumps up briefly during a shift before the next gear takes hold, as though the clutch had been dipped. On an automatic that gap is where the gearbox is meant to hand drive from one clutch pack to the next, and a flare means the pack taking over is slipping as it engages. Worth reporting separately from general slipping, because a flare on one particular change points at one particular element and is a much narrower diagnosis than a gearbox that slips everywhere. Note which change it happens on and whether it is worse when the fluid is hot.
Also described as: revs flare on gear change, engine revs up between gears, revs jump when changing gear, flaring on shift, revs rise between gears, دور موتور بین دنده بالا میرود, موقع تعویض دنده دور میگیرد, se disparan revoluciones al cambiar, suben vueltas entre cambios, revoluciones se van al cambiar, الدورات تقفز بين الغيارات, ارتفاع الدورات عند التبديل, الدورات تطير عند نقل السرعة
Some causes mean you should stop driving
1 of the 8 codes that produce this symptom indicate a fault where continuing to drive risks damage or is unsafe. If the symptom is sudden or severe, treat it as one of those until a scan says otherwise.
What this usually means
A flare is the gap where the gearbox is meant to hand drive from one clutch pack to the next, and it means the pack taking over is slipping as it engages. The engine, briefly unloaded, runs up — exactly as though somebody had dipped a clutch mid-change.
Report it separately from general slipping, because it is a much narrower diagnosis. A gearbox that slips in gear has a problem with holding; a gearbox that flares has a problem with taking up, and a flare on one particular change points at one particular element — the clutch or band that ratio applies, its solenoid, and the circuit that fills it.
Pressure and fill time are the two variables. If the incoming element fills too slowly, or is applied at too low a pressure, it slips through the moment where it should be clamping. That is a solenoid that has drifted, a valve bore leaking past its spool, a seal in the clutch drum, or fluid that has lost the friction characteristics the calibration assumes.
Worse when hot is diagnostic. Fluid thins with temperature, so a marginal seal or a worn bore leaks more, and an element that just about clamps cold slips warm. A flare that only appears hot is a pressure problem before it is a friction one.
And a flare that arrived after a service is adaptation until proven otherwise — fill times are learned values, and fresh fluid changes them.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Flare on one particular change, others clean | The element that ratio applies — its clutch pack, its solenoid, or the circuit that fills it | Note exactly which change and whether it worsens hot. Compare commanded against actual pressure through that shift. | Renew the solenoid or repair that circuit. A single-change fault is far narrower than whole-gearbox slipping. |
| Flare only once the fluid is hot | Pressure rather than friction — a marginal seal or worn valve bore leaking more as the fluid thins | Measure line pressure hot as well as cold. A cold test passes and proves nothing here. | Service the valve body or renew the seals the pressure test implicates. |
| Flare on every change | General low pressure — fluid level, a tiring pump, or a leak the whole system shares | Check level by the manufacturer's procedure, then measure line pressure against specification. | Correct level, or repair the pump or leak. Treat this as slipping rather than as a shift-quality complaint. |
| Appeared after a fluid service or a repair | Adaptation not relearned — fill times are learned values and fresh fluid changes them | Ask what was done and whether the relearn was run. | Run the adaptation procedure and drive cycle before considering anything mechanical. |
| Flare with a burnt smell or dark fluid | The element has been slipping long enough to cook its friction material | Inspect fluid condition and look for material in the pan and on the magnet. | Overhaul that element. Adaptation and solenoids will not restore worn material. |
| Engine speed rises and stays high with no engagement | Not a flare — that is a failure to engage at all, which is a different and more serious complaint | Distinguish momentary from sustained. A flare resolves as the next ratio takes hold. | Diagnose as slipping or loss of drive rather than as shift quality. |
-
Flare on one particular change, others clean
- Likely cause
- The element that ratio applies — its clutch pack, its solenoid, or the circuit that fills it
- How to confirm it
- Note exactly which change and whether it worsens hot. Compare commanded against actual pressure through that shift.
- What fixes it
- Renew the solenoid or repair that circuit. A single-change fault is far narrower than whole-gearbox slipping.
-
Flare only once the fluid is hot
- Likely cause
- Pressure rather than friction — a marginal seal or worn valve bore leaking more as the fluid thins
- How to confirm it
- Measure line pressure hot as well as cold. A cold test passes and proves nothing here.
- What fixes it
- Service the valve body or renew the seals the pressure test implicates.
-
Flare on every change
- Likely cause
- General low pressure — fluid level, a tiring pump, or a leak the whole system shares
- How to confirm it
- Check level by the manufacturer's procedure, then measure line pressure against specification.
- What fixes it
- Correct level, or repair the pump or leak. Treat this as slipping rather than as a shift-quality complaint.
-
Appeared after a fluid service or a repair
- Likely cause
- Adaptation not relearned — fill times are learned values and fresh fluid changes them
- How to confirm it
- Ask what was done and whether the relearn was run.
- What fixes it
- Run the adaptation procedure and drive cycle before considering anything mechanical.
-
Flare with a burnt smell or dark fluid
- Likely cause
- The element has been slipping long enough to cook its friction material
- How to confirm it
- Inspect fluid condition and look for material in the pan and on the magnet.
- What fixes it
- Overhaul that element. Adaptation and solenoids will not restore worn material.
-
Engine speed rises and stays high with no engagement
- Likely cause
- Not a flare — that is a failure to engage at all, which is a different and more serious complaint
- How to confirm it
- Distinguish momentary from sustained. A flare resolves as the next ratio takes hold.
- What fixes it
- Diagnose as slipping or loss of drive rather than as shift quality.
Codes that produce this symptom (8)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P0730 Incorrect Gear Ratio Typical of this code High
- P0741 Torque Converter Clutch Circuit Performance/Stuck Off Typical of this code Moderate
- P0751 Shift Solenoid A Performance or Stuck Off Typical of this code High
- P0756 Shift Solenoid B Performance or Stuck Off Typical of this code High
- P0761 Shift Solenoid C Performance or Stuck Off Typical of this code High
- P0766 Shift Solenoid D Performance or Stuck Off Typical of this code High
- P0771 Shift Solenoid E Performance or Stuck Off Typical of this code High
- P0811 Excessive Clutch A Slippage Typical of this code Stop driving High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others with this symptom
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Revs flare between gear changes.