Skip the auto shop - Our mechanics make house calls

Q: RPM revs too high

asked by on

My car has a problem with the rpm. When in idle it revs to about 2000 rpm and that's when the compressor kicks out. When the compressor kicks in it goes down back to 1200 rpm which is really high.

My car has 188000 miles.
My car has an automatic transmission.

Hi, thanks for writing in. This is a sign of a failing idle air control valve. This is a unit that is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. However, when the engine RPM drops below the normal range of 800 RPM (for most cars), it is more than likely that you are dealing with an IAC valve problem. In cases where this valve is clogged or is nearing its replacement age, your vehicle will stall instead of idling after the release of the throttle. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this rough idling issue for you, and make or suggest any repairs as needed.

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

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: Horn/rear brake light fuse constantly blowing

Hello there, many common faults will cause the horn and rear brake light fuse to constantly blow on your 2006 Honda Civic. When a fuse blows after it has been replaced this indicates there is a electrical issue. The most...

Q: How do I use the child-protector lock?

The child-protector lock is a key safety feature that helps keep children secure in the backseat. When the child-protector lock is engaged, the rear doors cannot be opened from the inside, even if the standard lock is unlocked. This makes...

Q: Car shudders and idles low - 1992 Toyota Cressida

It is possible that this is a misfire condition either due to a faulty ignition system component or fuel injector that is creating a power imbalance that will cause a shudder sensation. The fuel system and ignition system should be...

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.