Skip the auto shop - Our mechanics make house calls

Q: My saturn will idle at about 300-450 rpm and then eventually shut off.

asked by on

My saturn vue idles extremely low almost to the point of cutting off and sometimes it does just cut off. It only acts up when the car warms up, but when it's cold it acts ok, but still idles low. We've changed the starter, the battery, cleaned the cadalidic converter. The check engine light will start flashing and it feels as if the car loses power and it doesn't matter how much you press the gas the car won't go anywhere when it starts acting funny. We've ran the codes and nothing shows up.

Hi There, It sounds like you may have a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • My saturn will idle at about 300-450 rpm and then eventually shut off.

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: Car wont start

The symptoms you describe sound like the fuel pump stopped working and the engine doesn't have the fuel pressure it needs to keep running. Have the fuel pressure checked to see if the fuel pump is not pumping fuel to...

Q: Car feels sluggish

Hi there: Once your vehicle starts, the job of the battery is pretty much complete. The alternator is what powers vehicle systems while the engine is running; which is possibly what's causing the battery to drain, and the engine to...

Q: No heat in cabin

The first thing to check is for both heater hoses going into the heater core to be hot. If one is hot and the other cold or just warm where the other one is hot then you have a blocked...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
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...