Q: Car is idling up and down while either parked or when driving.

asked by on

I recently replaced my Started in my vehicle. Since I got it back on all of a sudden its idle was off. I took it to Oriely's and had them put it on their computer. It came out with 4 error coded. It ended up being a sensor called oem or something like that I paid for the sensor and replaced it while I was there. It honestly went from its rough idle and it going up and down in rpm's randomly to perfect. There was no noise whatsoever I could barely hear the engine we thought it was fixed so he reset my computer check engine and let me go home. I drove the car and it was perfect but a few hours later it started acting up again. I took it the the local chevy dealer and they said that they put it on a computer and there was no issues. they said it was due to Carbon build-up, so I paid 200 and some dollars to get the engine cleaned. Guess what it did nothing other than it not idleling quite as low when the ac kicked on. essentially nothing has got fixed what is the issue?

My car has 160000 miles.
My car has an automatic transmission.

A: Hi there. I believe O'reilly's sold...

Hi there. I believe O'reilly's sold you an IAC (idle air control valve) from the description you have given. OEM is the acronym for original equipment manufacturer. Seems odd that it was only fixed for a couple of hours. Sometimes aftermarket parts will not perform as well as factory (OEM) parts.

Carbon build-up could cause idling problems. Assuming the Check Engine Light has not come back on, means the computer is not recognizing a fault. If the idle is stable and just feels rough, I would look into the possibility of engine mounts being at fault or maybe a tune-up that is due. I recommend having your vehicle's rough idle inspected and diagnosed by a certified technician, like one from YourMechanic.

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・Save up to 30%

Get a quote

What others are asking

Q: Overheating

Let's go over the basics to be sure nothing has been overlooked. Verify the actual temp at the thermostat housing and compare it to gauge position when hot. Make sure the cooling system is full of 50/50 Dexcool...

Q: idling problem with peugeot 406

Hello and thank you for contacting YourMechanic. When you start the engine up when it is cold and the engine idles rough or does not want to stay running, then this is an indication that the engine temperature sensor has...

Q: Truck goes into limp mode while driving

Hello. The P0068 diagnostic trouble code is an indication that there may be an issue with the manifold absolute pressure (MAP) sensor/mass airflow (MAF) sensor. The P0016 diagnostic trouble code is an indication that there may be an issue with...

Related articles

How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...