When a Spark Plug is misfiring, it is often most pronounced at idle speed. Since there are so many reasons that a vehicle can misfire, we recommend testing for trouble codes first. That would include lack of fuel pressure, bad fuel injectors, or even a timing chain (or belt) that has jumped. There are also non ignition related circumstances that can cause a misfire. The real question is, what is causing the misfire? There is more to your Expedition ‘s ignition system than just the coil packs. Anything else that you may feel is a result of the misfiring itself.
Misfiring is the most common symptom of bad Coil Packs. When you take your vehicle in for a tune up due to decreased fuel economy, checking the ignition system in general (including the coil packs) is going to be one of the very first places that a mechanic is going to look at. This leads to a decrease in fuel economy. The less efficient the combustion of your engine, the more fuel is going to be wasted. If you have one or more bad Coil Packs, it’ll cause the acceleration of the Expedition to be weaker, and you’ll probably feel a jerking sensation. The less cylinders that your engine has, the more that one cylinder not firing properly will have an effect on engine performance. If acceleration has diminished, it should be felt. There are other misfire related codes as well.Īs you hit your Expedition ‘s gas pedal, the fuel and ignition systems respond. This makes diagnosing the misfire a bit more straightforward. For example, P0304 is for a misfire in cylinder 4 in the firing order. P0301 through P0312- these trouble codes indicate that there is a misfire in one specific cylinder.A random misfire means is that a misfire is detected, but the ECM is not able to determine which one it is coming from, or the misfire is occurring randomly.
P0300– this trouble code indicates that there is a random misfire.There are several misfire related trouble codes. More often than not, your engines computer will be able to detect bad Coil Packs in your Expedition. The check engine light is one of the most common symptoms of bad Coil Packs. Here are the most common symptoms of bad coil packs: If you don’t have one, your local parts store can do this for you at no charge. We always recommend using an OBDII scanner to pull your trouble codes if the service engine soon light is on. There are a lot of potential symptoms related to bad coil packs in your Expedition. This can save you a lot of money over just replacing the whole set at one time.Ĭommon Bad Coil Pack Symptoms: Ford Expedition
Here’s a great YouTube video on how to do just that. It is possible to isolate which coil pack is bad by using a multimeter. If you do need to replace them all, they can be somewhat pricey. So much so that it’s actually a better idea to look at the plugs first. The symptoms of bad coil packs are almost the same as bad spark plugs. They receive instruction from the engine’s computer on when to fire the spark plugs. It’ll get worse as they lose their ability to fire the spark plugs.Ĭoil Packs take the place of the distributor and coil in older vehicles. Or it may have little effect at all on the engine’s ability to run. A bad oil pack can make your Expedition almost un-drivable. Bad Coil Packs are one of the more problematic ignition issues that can occur with the Ford Expedition.