Platinum plugs

My 2006 Lincoln Navigator has 60,000 miles on it. The platinum plugs are rated for 100,000 miles. My local Ford/Lincoln dealer claims that I should change out the plugs now because they will be near impossible to remove at 100,000. They say that at 100,000 the plugs will most likely have to be drilled out and helicoils installed for the new plugs and that it would be a cost savings to do it now. I don’t believe that but does anyone have any similar experience with platinum plugs. Comments?

Loosen them, then re-tighten them. No need to change them out unless you pay someone to do it, at which point you might as well just change 'em out because the plugs themselves are cheap.

Yes, there is some truth to spark plugs getting seized if left for 100k miles, sometimes. Doesn’t always happen, but it happens often enough that it’s not a bad idea to loosen and re-snug them once or twice per 100k

While I normally doubt dealer claims like this, certain Ford V8 have had REAL problems just as described to you by the dealer. Might be worth doing now.

Your Ford/Lincoln dealer should never have to drill out old plugs. Ford has a procedure for using penetrating oil to loosen long life plugs, and the fact that this particular dealership doesn’t know this procedure means I would not trust them to work on my car.

Just a couple weeks ago, I was talking to a Toyota service rep about a problem a customer was having with a trailer harness. He told me there was nothing he could do because Toyota didn’t design this particular vehicle (a Sienna) to tow. I asked, “Didn’t the Sienna have an optional towing package?” Sure enough, when he looked it up, it did have an optional towing package, so he was able to order a new trailer wiring harness for the vehicle.

I am often shocked to discover how little dealership employees know about the vehicles they service. They should know more than me!

Here’s more info on the problem, and a video claiming to show how to remove them:

Google ‘Ford spark plug removal problem’ for lots more info.

I would recommend changing them now as per the video and recommendations made. Even platinum electrodes erode over time, and as they erode and the gaps grow they place more stress on the coils. Plugs are cheap.

Besides, one of the problems Ford has had to confront is that the last threads on the plugs protrude past the threaded plug hole, and that allows carbon from the combustion process to deposit on those last threads causing difficulty unscrewing the plugs. The carbon-coated last threads can bind up as you try to pull them through the hole. Replacing the plugs now helps deal with that issue. Why let the carbon build up if you don’t have to?

I have replaced the plugs in several 4.6L Crown Vics which also recommend a 100K service life…The plugs came out okay, but the spark gap was open way beyond service spec. This puts a lot of stress on the expensive coil-packs (COPS) and the cars all ran noticeably better with the fresh plugs…If the dealership prices seem high, any competent independent shop can change the plugs for you…

Normally I’d say leave them, but this is a Ford and those are probably Autolite plugs. If you have the three valve engine, it may already be too late. I have seen and used Autolite platinum plugs and they did not work as well as any of the other brands and they did not seem to come with an anti-seize plating. Glad I used an anti-seize compound on them.