smc704

So I plan on changing my plugs soon since my 2004 5.4 is due. Maybe I should change the cop's too. The truck idles good, runs good at WOT. It takes a few seconds to start up.

Anyways I read up on accel and granatelli cop's for this motor. I've read some good reviews and some very bad like premature failure, poor construction with pieces breaking off.

So are these higher voltage aftermarket cop's worth it? Or are stock cop's sufficient? Or should I not even bother with replacing the cop's?

StalkerStang

I would keep your stock coils if they are working fine. Modern coils are already very high output, its not like the 80's and 90's when an MSD box and high output coil actually made a difference over stock. Waste of money IMO on newer vehicles.

What I would do is replace the coil boots and get a tube of the Ford electrical grease to coat the end of the boots as you put the coils back in.

Summers22

iTrader: (2)

^^^^I agree, just replace your boots and springs, use a small amount of di-electric grease on the boot ends like stated. I have always done this with COP's that have under 125K and cut a paper fingernail in half and filed the copper contact on both sides that sits up in the nipple of the COP after the boots and springs are removed.

OldMansTruck

I replaced with ACCEL COPs after my OEM's started causing problems. Ever since about every 10k miles i get a melted electrode and a new misfire. I've got all OEM's sitting in my garage and i am dying to put them back in. Ever since putting ACCEL COPs on i have replaced around 5 or 6 spark plugs in under 40k miles and 2 years.

smc704

Alright thanks guys. I definitely do not want to deal with new problems stemming from new coils. So is it with the 5.4 engine being naturally aspirated a higher voltage coil doesn't help with performance? I mean the stock coils are sufficiently powerful?

Mod (Ret.)

Yes.

Here's one example where it's to no advantage (and useless) to use anything other than Motorcraft.