Just a general maintenance question. How often should you replace the spark plugs, and how do you know when it's time? Is there anything else that should be done concurrently, and anything to watch out for? Thanks.

 

I see yours is an 05 and they have the spark plug design that will break off if left in too long. Ford had to put a TSB out about how to remove them , and a special tool to extract the broken part if you do break them. The really sad part is , if you have a dealership change them and they break one , Ford doesn't cover them and you have to pay to have the broken part removed. I've changed mine a bunch and I've never had a problem , but I've never had more than about 18k miles on mine.

 

I changed mine at 50k, had two break off. Theres a kit made specifically for our engines that makes getting them out easy, found it on amazon for like $70. Theres a TSB with instructions on how to get them that helps too.

 

I thought I had heard something like that- scary. I've never changed them myself, but would rather try to do it that send it to the dealership- I'm coming up on 45k and I'm the second owner- seriously doubt they've been changed. I've done a ton of maintenance on this car and it all looks like I'm the first one who did anything. I'm gonna google and see if I can find instructions. Thanks for the info.

 

It really varies on whether they will break off or not. I've had 3 valves with 120k on them, in for their 1st plug change and all come out cleanly. While I've also had some with 60k break off.

My method: if I'm doing plugs combined with a service, I usually let the plugs soak in PB blast and do the service 1st with the plugs last. So about a 45-1 hour soak, then I give them a quick zap with my 3/8" impact and then take them out with a ratchet.