Skip the auto shop - Our mechanics make house calls

Q: My car is skipping - do I need new spark plug wires?

asked by on

my mechanic changed spark plugs, but my car is still missing if u no what I mean, he suggested new spark plug wires, since I've had the car some 75000 miles,

My car has 179000 miles.
My car has an automatic transmission.

A: Old or faulty spark plug wires can definite...

Old or faulty spark plug wires can definitely be a cause for the engine to misfire, however there are numerous other reasons that may also cause this to happen. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

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・Save up to 30%

Get a quote

What others are asking

Q: Clutch problem

Hi. Clutch problems are not limited to the disc wearing out. Pressure plate, throw out bearing or hydraulic system issues could also be at fault depending on the type of problem you are having. If the clutch is slipping, then...

Q: Brakes don’t work, worried about a crash

Your vehicle is unsafe to drive in this condition and shouldn’t be driven until your problem is repaired. Being that you towed it to a shop, it appears from your question that they were unable to provide you with an...

Q: Engine problems

If the engine is overheating then you will need to see if the upper and lower radiator hoses are both hot, but the lower one will be cooler than the top. This tells me the thermostat is open. If the...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...