Ford replaces the whole set much of the time.
When a coil does go down, it can damage the rest of the coils.
The Taxi Companies I deal with started doing entire sets and it reduced
their down time significantly. Many shops find that replacing single coils
without testing the entire set leads to comebacks. One new coil on the
engine can pull a higher amp than the rest because of the resistance
difference, causing the new coil to go down. Failure of older coils often
occur as well, leading to additional labor charges to the customer. When you
start seeing coils go bad, the rest are not far behind usually.
If only one are bad, the resistance on the older coils are higher than the
new replacement coils also, which eventually leads to more failures. If the
older coils are tested, if there is a significant difference in the
resistance, the entire set should be replaced.
(@6.5 amps Primary Current) (@9.0 amps Primary Current)
Primary Resistance 530 m? 410 m?
Secondary Resistance 5500 m? 4000 m?
I've been selling full sets to installers for 3 years.
These are awesome, only problem is that they were mainly used on the higher
end Ford models like Lincoln. So if your vehicle isnt original with them,
then you have to change out the whole wiring harness and ECM to make the
change. The nice thing about COP's is that the coil on-time or charge time
is greatly enhanced which reduces the chance of a misfire at higher RPM's.
If you have a 4.6L engine with regular DIS, I recommend boning the cash to
replace it with a COP system. you will definitely notice a difference in the
way your engine runs. Hence the term purrs like a kitten.
I have a 5.4 in my van, and it has COP. Thankfully it only has 25k miles on
it and I have the extended warranty to 60k. We drive around 8-10k a year,
so it'll be a while before I need them.
I do like COP tho. I had COP on my 2000 Taurus Duratec and it worked well.
The Lincolns and TC's (high end stuff) and a few Stang's use the 32 Valve
engines that take the DG481 coil which requires a straight boot. Most of
the rest of them used the DG491 until that was superceded by the DG508
around 2004/2005 that have a 15 degree angle to the boot.
The one with the angle dominates the market, thats what I have.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.