my original plugs are on my JCW 2004 MINI S
Went to put new plugs in at 128k and they aren't budging.
How hard do I crank or should I take it to the dealer? They aren't budging with full shoulder strength on the tool. Are they seized? Is there something I could spray down there to loosen them?

 

The dealer has no magic to get the plugs out. If one snaps it snaps!
I would have to use my 24" breaker bar on this job. Presuming the plug comes out buy/borrow/hire the correct tap, cover it in grease and chase the thread.
Use plug grease/never sieze in the new set.
If one snaps -at leaset you didn't have to pay someone to snap it for you. The repair cost would be the same, as the dealer will not take the blame..

 

I would spray some PB down in the spark plug holes and let them soak for up to 24 hours and then give it a try then. Good luck.

 

I would recommend kanokroil instead of PB. It's f-ing magic. Make sure the engine is stone cold when cranking on the plug and go easy on it.

When/if the plug breaks free, back it out slowly. If it feels like the threads are starting to bind up again (even slightly), thread it back in a 1/2 turn and back it out again. Repeat this until it's completely free. This has been a fail proof method for me; I've never stripped a spark plug thread in 20 some odd years of working on cars.

 

Drove 50 miles round trip to get the Kanokroil even though I had the PB in the garage, Not taking any chances! and Success! Blackeyedsuzie Always my Faithful! gave up the old spark plugs in favor of new equipment and a special bath!
You Betcha I talked her all the way through it!

 

Did you really think the Kanokroil really work better than PB Blaster??? You've used PB but gave it up for something you never used before...

 

Yes try the Kanokroil that stuff is good.

If it still doesn't work better, try to warm the car up for a minute. Not full temp, but just a little heat in the engine may make them come out.