Q: RPM fluctuates, car jumps at speed decrese

asked by on

The issue with my car happens when I'm bringing the car to a halt and slowing down. Then, as the RPM is close to 1, the car would jump forward and increase the RPM. Then it would go down and get back to normal. This happens occasionally and while it lasts, I'm not accelerating. What could be the cause? Thanks.

This sounds like a shifting issue.

The transmission needs to select the proper gear based on how it is adapted when you come to a stop. If the shift is delayed, then the load on the engine will momentarily drop while the transmission is between gears. This can cause an increase in RPM and then, when the gear is engaged, the vehicle has a slight jump to it. This can be from reasons from faulty programming to a lazy solenoid.

Fault codes should be read out and the latest software should be installed. This is generally a dealership fix, as they will have the proprietary software necessary to correct program levels and read solenoid statuses.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. RPM fluctuates, car jumps at speed decrese

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Strange rattling sound from the engine when RPM goes down from 3,000.

Hi there. The noise that you are hearing is heat shields on the exhaust system are loose causing a rattling noise. Either the shield on the manifolds are loose or the shields on the catalytic converter are loose. If you...

Q: Fluctuating oil pressure - 1980 Jeep CJ5

The fluctuating oil pressure indicates an inadequate oil supply to the oil pump. It is possible that there may be some trash or sludge buildup on the pickup tube screen limiting the oil supply at the oil pump. An engine...

Q: No response when pressing on the gas pedal.

Hi There, It sounds like you are describing the symptoms of a failing throttle position sensor. The throttle position sensor monitors the throttle position of the throttle plate inside the throttle body in relation to your foot position on the...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...