Skip the auto shop - Our mechanics make house calls

Q: Engine idle fluctuates

asked by on

Car rpm surges depending on how deep clutch goes in if clutch all the way in car rpm would stay around 2k rpm but if it's only half way it idles correctly After that car stopped getting the gears only gear i can shift into its 3rd the others dont go in like if clutch wasnt pressed at all

My car has 120000 miles.
My car has a manual transmission.

You may have a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it 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 with the help of the idle air control valve. 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. When you have the clutch depressed half way, the reason this may smooth out the idle is that this places the engine under a load that it may not otherwise be subjected to when the clutch is pressed all the way in. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

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: Minivan shutting down; cleaned IAC

Hello. It is possible that cleaning the Idle Air Control (IAC) valve would fix this problem permanently. However, because it is not likely that all of the dirt was cleaned out the IAC valve it may fail again. It would...

Q: My actual handle isn't broken. It's Just won't open

The door handle inside a vehicle of your year and model uses a mechanical linkage to transfer the force applied to the handle then to a device that unlatches the door at the jamb. The linkage inside the door may...

Q: My 1997 toyota camry le v6 is tuning rough at 60 mph, and is vibrating a little when I press the gas at any speed

Hi there. The VSV Valve is a part of the EGR system, which recycles un-burnt hydrocarbons from exhaust back into the combustion chamber in attempt to reduce overall vehicle emissions and improve fuel efficiency. Any part of the EGR valve...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.