The Lemon IndexAn idle or RPM that rises and falls on its own usually points to an air leak or the idle control.
Fix soon. Usually OK for short trips. Get it checked soon.
A vacuum leak. Then: a dirty throttle body or idle air control valve; a faulty sensor (mass air flow, throttle position).
Owners describe this in 5,352 complaints to the U.S. government, most often on the Ford F-Series.
Cars owners report it on most
Complaints describing this symptom, by model, all years. Raw counts, not a failure rate: popular models get more complaints.
Model years that report it most
| Model year | Complaints | Share |
|---|---|---|
| 2006 Ford Freestyle | 59 | 5% |
| 2007 Toyota Camry | 52 | 1% |
| 2005 Ford Freestyle | 50 | 3% |
| 2010 Ford Fusion | 43 | 0.8% |
| 2010 Ford Escape | 34 | 2% |
| 2015 Jeep Cherokee | 30 | 2% |
| 2005 Ford Taurus | 28 | 4% |
| 2012 Ford Focus | 27 | 0.7% |
| 2007 Ford Freestyle | 25 | 3% |
| 2013 Nissan Sentra | 25 | 4% |
| 2003 Honda Accord | 23 | 1% |
| 2014 Ford Focus | 23 | 0.9% |
Each row is that model year's record in NHTSA complaints, not the history of any one car. Share = complaints describing this symptom out of every complaint we hold for that model year (shown when the year has 50+ complaints).
Where it makes up the biggest share
2017 Nissan Sentra · 6% 2014 Nissan Sentra · 6% 2016 Nissan Sentra · 5% 2000 Volvo S80 · 5% 2020 Kia Soul · 5% 2015 Nissan Sentra · 5% 2006 Ford Freestyle · 5% 2016 Nissan Altima · 4%
Model years with 150+ complaints in our data and 10+ describing this symptom, ranked by share. A high share means owners of that year who complained often mentioned it.
The details
Common causes of RPM goes up and down
- A vacuum leak
- A dirty throttle body or idle air control valve
- A faulty sensor (mass air flow, throttle position)
- A slipping transmission (RPM jumps without more speed)
- An EGR valve stuck open
General causes, not a diagnosis. A shop should confirm the cause with tests before replacing parts.
Is it safe to drive if the RPM goes up and down?
Fix soon. Usually OK for short trips. Get it checked soon.
Get help right away if the car surges forward at a stop; it stalls.
Of the 5,352 complaints describing it, 6% mention a crash, 2% say the car was towed, 0.7% mention a fire and 2% report an injury.
What the complaints show
The parts owners filed these complaints under: power train (43%), vehicle speed control (31%), engine (22%), electrical system (14%). A complaint can list more than one.
Median odometer reading when owners reported it: 60,000 miles.
Most reports by make: Ford (1,324), Chevrolet (488), Nissan (453), Toyota (431), Honda (300).
What owners say it cost to fix
Repair bills owners named in complaints that describe this symptom (cooling, engine, exhaust & emissions, fuel system repairs): the middle half ran $1,000 to $5,300, typical $2,900, from 29 bills.
Each figure is one repair bill as an owner wrote it in a complaint, not a quote for your car. Prices vary with the part, the shop and the year.
Engine codes that come up with it
Trouble codes owners named in these complaints more often than in other symptom complaints. Look up any code →
Related symptoms
Car shakes at idle Car jerks when accelerating Car stalls at stop or idle Car accelerates by itself Transmission shifting hard Transmission slipping
Quick answers
What causes RPM goes up and down?
An idle or RPM that rises and falls on its own usually points to an air leak or the idle control. Common causes: a vacuum leak; a dirty throttle body or idle air control valve; a faulty sensor (mass air flow, throttle position); a slipping transmission (RPM jumps without more speed); an EGR valve stuck open.
Is it safe to drive if the RPM goes up and down?
Fix soon. Usually OK for short trips. Get it checked soon.
Which cars have this problem most?
In complaints to NHTSA, owners describe it most on the Ford F-Series, Ford Escape and Ford Focus. These are raw counts, so popular models rank higher; complaints are owner reports, not proof of a defect.
How much does it cost to fix?
In 29 repair bills owners named in complaints describing it, the middle half ran $1,000 to $5,300. The right repair depends on the cause.
Counts: NHTSA owner complaints whose text describes this symptom (we matched owners' own wording, then read samples to check the matches). A complaint is an owner's report, not a diagnosis or proof of a defect. Causes and advice are general information in our own words, not repair advice for your car. Every symptom · Engine code lookup