Skip the auto shop - Our mechanics make house calls

Q: Random misfiring. Check engine light is on. Running real rough. Bad PCM?

asked by on

The check engine light is either on or blinking the engine is running real rough different lights on the dash go on and off and very loud when driving. Wants to stall at idle, shakes badly. Changed out the spark plugs and had absolutely no effect.

My car has 156000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. There are severa...

Hi, thanks for writing in. There are several malfunctions that can cause a rough running condition. The spark plugs could be an issue, but it could also be a problem with the ignition, a fuel supply problem, or even a wiring issue. It would be best to have a certified mechanic, like those available at YourMechanic.com, to perform some diagnostics on the vehicle to identify exactly what is causing the rough running condition.

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

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: front left making a rumble. doesnt do it when slightly turning left

It is likely that the left front wheel bearing has failed. When you swerve to the left on a ramp, what you doing is transferring some of the weight of the car from the left to the right. The transference...

Q: Won't start say running

Code 42 is indicative of an auto shutdown relay problem. This can be caused by a wiring issue to the fuel pump - most likely a short or broken wire. Sounds like it's time for an electrical diagnosis. A professional...

Q: Load on truck's engine causes loud knocking noise

Hello. It sounds like there may be a problem with the piston or the valves in cylinder 5. Loose rod bearings to the piston can cause a knocking noise and/or a misfire condition. A worn out piston can also cause...

Related articles

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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.