Skip the auto shop - Our mechanics make house calls

Q: Low idle problem

asked by on

I just replaced my IAC control valve and the Alternator as well because of low idle issues. Unfortunately, Iam still having the same low idle issue especially at start up in the morning. But after the car runs a while it smoothes out and drives normal until I go to start it up again and then it Idles low for a few minutes then it runs smooth . What else could be causing this problem with low idle? Also when driving on the highway at about 60 miles an hour it feels like the car jerks back as if it's not in overdrive. Please help me figure out what's caising me this problem.

My car has 77000 miles.
My car has an automatic transmission.

A: Hi there. If the idle control valve is good...

Hi there. If the idle control valve is good then the problem is typically caused by a vacuum leak or an issue with the throttle body. I usually check the engine for vacuum leaks first. It may be a vacuum leak in one of the hoses or in the intake manifold. The intake gasket is a common failure.

If there are no vacuum leaks, then I would test the throttle position sensor to make sure it is reading correctly. If it is also reading fine, then I would check the throttle body itself. If the bore or plate is worn then this will occur. If you want to have this low idle problem inspected, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.

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!

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: 1995 Ford Explorer defrost only

I would recommend smoke testing the vehicle to determine the source of the vacuum leak. This will send smoke through the engines vacuum lines and emit smoke wherever the leak is. Another way to find the vacuum leak is to...

Q: 95 grand Marquis GS

You may have a blower motor with debris that got into it from under dash. It may be paper or other debris that are in the fan blades and will make a rattle slapping noise and can only be cleaned...

Q: Car lost power and stalled

Hello there. It's kind of odd that your 2011 Mazda2 is exhibiting this issue with so few miles on it. However, many different faults can cause the vehicle to stall. The most common would be the fuel pump, fuel filter,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
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...