2003 Crown Victoria & Crown Vic CVPI & P71 Ignition Coil Packs

 

The 2003 Crown Victoria civilian and police interceptors all use the exact same 4.6L V8. There are other differences like the alternator, tuned PCM, and different suspension, but they all use the DG508 ignition coils in them. Replacing the coils in these 2003 Crown Victorias is not a difficult job. Many owners feel intimidated to do this job because of what they heard of with the spark plug blow out issue, or it just looks like a rats nest to many people. With simple tools (7mm socket, flathead screwdriver, extension, 5/8 spark plug socket) this job can be done pretty quickly. If you decide to change your spark plugs along with your ignition coils, we recommend going to around 20 ft/lbs instead of 11 ft/lbs like Ford recommends. The recommended torque specs were too low. The spark plugs would begin to back out until there is only a couple of threads holding them on, then they will blow out of the cylinder. If your valve cover gasket is also leaking oil onto the spark plugs and ignition coils, you will want to get this replaced, or you will be doing this job all over again, and purchasing even more ignition coils. If you notice the rubber boot on any coil pack swelled up, you have a leaky gasket. 

 

2003 Crown Victoria Misfire OBDII Codes

 

Common error codes you will receive are P0301, P0302, P0303, P0304, P0305, P0306, P0307, and P0308. The cylinders are numbers 1,2,3,4 from front to back on the passenger's side bank, and 5,6,7,8 on the driver's side bank. We have an image of the cylinder numbers so you can be sure you are working on the right cylinder.  If you have a constant misfire, you can simply unplug the harness from the misfiring coil pack to see if there is any change in the engine idle speed. If you feel a change, then that coil is most likely working just fine. You can also swap the ignition coil to another cylinder to see if the misfire code will follow the coil. If you have an occasional misfire, you will want to get an OBDII scanner with Mode 6. Don't even bother bench testing an occasionally firing ignition coil pack because they only misfire under load (accelerating, towing, etc) and operate just fine while cruising. You will not get an accurate reading. The only other way to test an ignition coil without a Mode 6 scanner is with an oscilloscope. Most people don't have these unfortunately, and they are quite pricey. Mode 6 scanners start at around $50 online. This is a lot less than what you would pay for the diagnostic itself, and you can use this scanner on all cars 1996 and up. We also include dielectric grease with our ignition coils, which helps to keep moisture away from the spark plugs and coil boots. This is to be applied lightly on the inside of the bottom of the rubber boot where it meets the spark plug.