Skip the auto shop - Our mechanics make house calls

Q: Check engine light and car idles low/runs differently

asked by on

Check engine came on, hesitated to start and when accelerating car hesitates to push while driving. Also idles low. Had full maintenance about a year and a few month ago including spark plugs etc a complete tune up, spent nearly $2k in repair. What could be the problem?

My car has 153000 miles.
My car has a manual transmission.

This may be related to 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. 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. When the engine RPM drops below the normal idling range of 750-800 RPM (for most cars), 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 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: went over a speed bump now have a scraping/grinding noise under the bed when driving

It sounds like one of your leaf spring shackles has broken. It is very common for them to get rusty and break. The noise you are hearing is probably the shackle running on the underside of the bed. Go...

Q: Loud whine from the front of the engine, and has no power from my turbo. It also idles very high around 2000 rpm.

Check the hose from the MAF sensor to the throttle body and see if there is a leak or if the hose clamps are loose. This will produce a vacuum leak before the intake and make the engine run different...

Q: What damage maybe caused from starting car with disconnected transmission lines and empty radiator 2000 Ford Mustang

Hello. As long as the vehicle was not ran for too long then no damage should occur. The lack of coolant typically only comes into play if the engine runs long enough to overheat. If the transmission lines are disconnected...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...