Skip the auto shop - Our mechanics make house calls

Q: Idle issue

asked by on

Hey just had a quick question I have a 2002 Honda civic automatic 1.7L and so I had a question earlier regarding that when I turn it on it would kind of rumble so I seen a hairline crack in the exhaust manifold which i got patches up pretty nice but then it still was the same so I let the car idle and pulled out each ignition coil one by one and there's 4 altogether and so I pulled 3/4 and the Rpm went down as.it should right? And then one of them when I pulled out it didn't.make a difference in the Rpm so then I switched two ignition coil and the problem stayed in the same cylinder could that mean I have a bad spark plug that needs to be replaced?

My car has 290000 miles.
My car has an automatic transmission.

Cylinder misfiring can be caused by: Ignition coil, spark plug, fuel injector, or a wiring issue to the coil or injector. By moving the coil from the misfiring cylinder to another and the misfire staying with the original cylinder, you have basically eliminated the ignition coil. You can try the same thing with the spark plug before buying new ones. If again the misfire stays with the same cylinder, then you have a faulty injector or signal/wiring issue to that coil or injector. Also, mechanical damage with that cylinder such as a damaged valve or valve seat can also cause a misfire. If you need further assistance with your misfiring issue, a certified technician from YourMechanic would be pleased to come out and help you figure out what is going on.

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: Clutch and brake pedal feel strange

Hi, it sounds like you have a defective clutch master cylinder. I would inspect the clutch master cylinder as well as the slave cylinder. To replace the clutch master cylinder drain the brake fluid out the reservoir then disconnect the...

Q: Car won't idle, sputters and shuts off. 1995 BMW 318is

Hello there, a few different faults could cause this issue on your 1995 BMW 318is. When oil and coolant mix, the usual suspect is the head gasket. The mixing of coolant and oil may take some time to develop and...

Q: Coast Replacing a fuel filter and a fan a fuel pump in 2002 Buick Regal

Hi...both of these services are available. To obtain an exact quote for the fuel pump replacement, please click on "Get a Quote" at YourMechanic's fuel pump replacement service page. Similarly, to get an exact quote for the replacement of your...

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 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...
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...