Not positive it coil pack just yet but randomly got p0300, p0305 and p0308 today when coming to a stop. Felt it misfire for about 5 seconds then went away and didnt return for the other 10 I drove. I believe 5 and 8 are on the same coil so leads me in that direction. My plugs and wires have maybe 15k on them but going to check them as well.

Anyway my real question is are the cheap ones any good. I see them as cheap as 16.99 on ebay, I also see them on rock auto in the 50ish range, the AB has the for 270. I have had them go bad on a GM car before and the cheap ones were just fine on it but curious if the Disco is as picky? I was going to just grab the ones on rockauto since dealing with warranty there isnt so bad (where ebay I can imagine is a pain) in case I did have issues. I put maybe 3k miles I year on the disco so if cheap one only last 20k miles that is still good with me.

 

Why are you guessing, do you have a check engine light, if so what are the fault code numbers? Who's 15,000 miles old plugs and wires are you running?
Only buy the better coil pack, the cheap ones are cheap knock off's and do not make as much voltage as you want.

 

Really...

In my experience coils usually seem to work or not work, but that's not to say one could be on its way out. Only ever used oem so can't comment on if a cheap one would do the trick or not. I personally would start by just pulling both plugs and having a look at the plug and boot and see what you see. I would think plugs and wires should last longer than 15k, but I guess it all depends on what brand you may have used, driving style, driving conditions, etc.

 

I'm using the el cheapo ones off of eBay right now and have for about 10k miles with no issue. I'd be willing to bet that mike is right and they put out less voltage, but I'm still laying down 230 hp and 315 torque at the wheels so they couldn't be THAT bad. Definitely better than the ones that are going out, especially if you don't have the money for an OEM set.

 

...at the wheels? With what motor? Me want!

 

I think our D2 is running a little "doggy"... so husband put new plugs in. Quite a bit better.. but not perfect. So, where are the coils located? *not at the plugs.

 

Alex, you are not putting 230 H.P. at the wheels, probably closer to 180 or so.
Also, lower out put coils do cut into the torque and horsepower.

Calamityj, how many miles on your truck and did your husband also replace the plug wires?

 

I've got the 4.6, but it's far from stock. Shaved heads, cam, Port and polish, intake, exhaust, the whole 9 yards.

Hate to break it to you Mike, but thats where she dinod at. 0-60 in 9.1 seconds the last time I checked, though I've gone up a couple inches in tire size since then and that was a better than average tank of gas.

Edit: I just saw I was 10 off, typo. She dinod at 220. Still though, not shabby by any means.

 

You can get coil packs that cross list with a KIA. They are much cheaper and work just fine.

 

Anybody ever thought of a coil upgrade? Looks like MSD makes an aftermarket Ford set that looks really similar other than the different plug which I doubt would be hard to change. You'd just have to cross reference wiring diagrams.