Q: My car had a rough idle, and if I sit at a red light or let the car run in idle for a few minutes my check engine light starts to

asked by on

My car has a rough idle, and constant flashing CEL and service stabilitrak, and traction control light comes on, I had the code ran and it comes back as a misfire on cylinder 4, I was recommended by the auto zone clerk to change coil and plug. Plug was fouled, replaced coil and plug. No change.Any ideas of what it could be?

My car has 153000 miles.
My car has an automatic transmission.

A dead misfire on a single cylinder may be deeper than just a spark plug. If the compression for that cylinder is very low, the cylinder cannot fire. Low compression would be caused by worn piston rings. Also, if the fuel injector is leaking or not flowing enough fuel, this may cause a misfire as well if the injector is leaking bad enough. A fouled spark plug usually leads to a coil that is not functioning or lack of compression in that cylinder. If you would like to have this taken care of, a qualified professional from YourMechanic can come to your car’s location to diagnose the rough idle and help you move forward with repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My car had a rough idle, and if I sit at a red light or let the car run in idle for a few minutes my check engine light starts to

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: Pontiac Grand Prix shaking at 30 mph

If there is a broken piece on the rim it will cause the rim to be out of balance and shake when the car picks up speed. I would definitely get the rim fixed and re-balance and see if that...

Q: Fluttering and bogging out when accelerating

Hello. Fluttering and bogging can be caused by a wide variety of issues. A few common causes are issues with the fuel, ignition, or engine management systems. If there is an issue with any of the components, such as the...

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 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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...