Skip the auto shop - Our mechanics make house calls

Q: Rough idling after sitting for a few days

asked by on

My car has gone 60,000 miles and it has been idling rough. I had the spark plugs replaced recently but it didn't fix the problem. This usually happens when the car sat for a few days. What is causing this? I should mention that I fill it with high-quality gas.

Hello. If the ignition coils are misfiring, this could cause the spark plugs to misfire and the car may idle rough. If this is the case, the ignition coils will need to be replaced in addition to the spark plugs that you replaced recently. It is possible that there is a high carbon buildup in the throttle body and intake, causing a rough idle condition. In addition, there are several sensors in your engine that have been known to cause this same problem. Have a certified technician, like one from YourMechanic, complete an inspection of your vehicle to determine why your car idle is rough.

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: Cylinder 6 misfiring

Since you have already replaced the plugs and wires, that narrows down what the problem could be. The most likely culprits of your issue are a faulty fuel injector or ignition coil. However, there is a slight chance that there...

Q: Convertible top won't work

Hello. Resetting the convertible top involves the back seats being taken out and the convertible motors being disconnected. The purpose of this is to gain access to the micro switch, which is attached to the side latch. The top must...

Q: My car runs poorly when the idle sensor is connected, without it the car runs fine

The throttle position sensor is designed to monitor the position of the throttle butterfly valve in relation to the throttle pedal position. If the engine runs rough when it is plugged in and runs fine when it is unplugged, then...

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...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...