I am close to replacing the spark plugs, and someone somewhere said might as well do the coils at the same time. When I had a few minutes, a google search turned up a set of 6 coils for $150-200 total. Then someone else posted about only using OEM Ford stuff. Close to $200 EACH. So back to the question of whether I should even mess with them. Truck is nearing 100K miles, and I'm extra sensitive because I pretty much always have the auto start/stop turned off--so engine is always running. Replace plugs but leave coils alone? I don't have any problems at all, but I just feel like it's time for the plugs and I'd hate to leave them in so long they "freeze" or get stuck.
Thanks,
Mike Todd

 

Save your moneys. Don't replace coils until its actually needed.

 

The maintenance schedule in your owner manual doesn't include coils, because they don't wear out. Replace one if it's stopped working. I've had 2 go bad in the last 20 years.

 

Coils no, the boots at that mileage wouldn't hurt. You can test the coil windings with a multimeter. Looking at another coil thread I saw a post by Bluegrass. He gives good reasons to use Forscan to check for misfires and why checking resistance won't work.
Use di-electric grease on the boots when reinstalling.
https://www.rockauto.com/en/moreinfo...=10150&jsn=647

 

Don't replace working coils and doubly so don't pay $200 per when you do. The Motorcraft coils for your truck are 57 bucks each at Rock Auto.

 

oops. Boots? Thought those were part of the coil. Thanks.
Mike Todd

 

Nope. The boots are the rubber part that slips down over the spark plug and they are detachable from the coils. Sometimes when you are trying to pull the coil pack to get to the spark plug the boot will stick to the spark plug and only the coil will come up. Then you have to reach down into the spark plug well with a pair of needle nose pliers and pull off the boot. So when you install coils you should always make sure to smear a tiny bit of dielectric grease on the inside of the boot.

 

I bought all six spark plugs and all six coil packs from my local Ford dealer this past October. Total cost was $850 so not sure where that $200 per coil figure comes from.

 

$200 x 6 = $600 those were some expensive spark plugs you got.

 

Must be some of that "new math" they are teaching in schools today...........................