You can get OEM Motorcraft coils from Rockauto for about $43 each plus shipping. DG508 is the part number.

I think Rockauto has a 5% discount going on now, too. Use this code. Expires Feb. 5, 2012.

77052056371924

 

Sorry 115$ was for the Lincoln when I owned it. Motorcraft is the way to go.

 

I hope I have better luck with the eBay coils...
If they turn to crap then I'll get the OEM coils from rockauto.com
Thanks for the tips

 

i have had my excursion for almost 9 years now with a 143000 plus miles.

when will it be a good time to change them. lol <!-- / message --><!-- sig -->__________________

 

I wouldn't touch them till one goes, but when one goes, save the headache and replace them all.

 

Lots of luck with those ebay COPs , I bought a spare for my GXP Northstar only to have it go stone dead in 9 days (700 miles for me). Take the free advise, OEM best way to go, you can find good pricing on OEM COPs from Amazon or other internet sources including a 1 year warranty .

Note that the defective COP I purchased came from a company on ebay called AIP. Still waiting for them to make good on their ONLY 90 warranty... four days/emails later and counting??

 

I have found bad coils are really not the problem, many times its bad boots.
The best way I have found to check a boot is first inspect the boot for white, grey or brown carbon traces. If this is not present then take your thumb and forefinger and squeeze the boot if you see cracks its toast.
I replaced the plugs in my X back in the summer and would have sworn it had a bad COP but after replaceing 4 boots and all plugs no problem at all. Mine had a skip that would just come and go.

 

I agree with Urban. Last time I changed the plugs, I also got some replacement boots and replaced them as well.

 

Boots would normally be suspect only on old high mileage COPS, otherwise the boots have been contaminated/mishandled if they fail on low mileage COPS. Also be aware of the cheap China made no label aftermarket replacements COPS which fail vary early in the life cycle as compared to OEM.

 

I agree with you, but the problem still exists in many cars due to owners and/or car dealers steam cleaning the engines. It seems once water gets in the plug wells the boots get steam cooked by the heat of the engine and just go down hill from there even on 50,000-80,000 mile cars. I have seen this time and time again on cars.
When heat and water get together we get pressure, these three elements of nature defy logic and the unusual happens. I have seen the COP boot coils turn green from water, heat and the silicone in the boot. The boot grease seems to intensify the heat, which in turn ruins the boot.
The boot will go bad usually before the coil.
This is just an observation I have seen where I live. Remember a COP consists of three distinct parts (1) Coil (2) Spring) (3) Boot, they must work together, but do not have to be replaced together.
It just seems that now days no one takes the time to see what causes the problem instead they just replace the part/parts until everything works.
To each his own, but the facts speak for themselves.
Seems the rule of thumb is don't fix it replace it.

 

Once again I would say contamination/mishandling as you eluded. The green could be copper corrosition or other chemicals i.e. road salt contamination. The contaminants allow the high voltage to track (conduct) along the boot seal but someone would really have to get carries away with the steam cleaning or as suggested earlier the COPS are high mileage units. Also sounds as though in your situation maybe the COP itself might not have sealed properly when manufactured. Have not seen these conditions on the GM COPS though.

 

It was such a long time ago that I replaced those boots but I can tell you that they were not original plugs. A few years before that, I had all the coils replaced. Fast forward to the time I replaced the boots...those non-original boots were cracked when pinched together and some were even slightly discolored. I replaced them and I will replace them again the next time I replace the plugs. It has become part of the scheduled maintenance for me.

 

I went through this last weekend where my truck was missing.

I just stopped into a mechanic and asked if he would scan it. He did at no charge! He found that cylinder 9 was the cause, under a load. I am new to the Ex and the V10. After finding out which was the cause I went to Napa and bought a new coil (came with the boot and spring) and a new boot for the old coil (if needed) (comes with the spring). I got home and had the truck running like new again in 10 minutes and all I needed was a new boot!

Later when I get time I'm going to inspect all the boots and plugs and replace whats needed!

 

And saved a chunk of change. You Sir repaired your truck and did not just replace parts.

 

I agree with UrbanXX with all the above posts. Change your boots before you go messing with the cops. (that sounded kind of funny).