I have a 02 F-150 with a 5.4 and all was great until 2 weekends ago when I washed it (hood open) then the next day I had a skip in it. It idles fine but when you get on it it’ll skip/miss. I thought maybe I got something wet so I took out each coil, blew out the hole but none seemed wet at all, and still missing. Ok so maybe something else got wet, but 2 weeks later and still missing? It doesn’t do it all the time, went for a ride last night and not too bad, skipped a few times but this morning it was pretty bad. Maybe just a bad coil? I thought they either worked or didn’t, not sometimes ok sometimes not. Any suggestions? I know the local dealer can hook it up and tell me but they want about $150 to do so.

 

Check engine light on? any codes?
If so, autozone and other parts store will pull the codes for free. Then determine what to do from there.

 

Coils can give intermittent problems. The intermittent problems usually show up when the engine is under a slight load and/or when the humidity is high. Some people recommend finding the engine speed/load range where the misfire is the worst and driving the vehicle under those conditions to try to set a code (illuminate the MIL). Then, have the code read to determine which cylinder(s) is/are causing the problem. Do not assume it is a coil, although that seems likely since they may have gotten wet during the wash job. It also may just be a coil boot - much cheaper than a coil. Also, it could be a plug, injector or low compression just to name the more obvious.

 

No lights and i don't know how to pull codes but assume the light needs to be on. I just went to lunch and it's definately missing a cylinder. Whatever was dying....has now completly died! I'm pretty sure it's a coil. When i removed them all i checked the boots and didn't see anything obvious. It's got 115k on it and this will make the third coil to give up. The thing that has/had me scratching my head is before they just died, they didn't think about it for a couple weeks, mabe a couple skips to make me go WTF...then dead. Now the trick......which one is it??? And FWIW, Ford wants $100 each, but at Advance auto an Accel coil costs $29....Hmmmm which one should i get.

 

Order a full set of 8 for about $80 on Ebay - search for "DG508". Global and Uneek are the 2 most reputable vendors. Accel cops are junk. The Ebay cops are essentially OEM without the Motorcraft branding.