Just blew a spark plug out of the head of my '04 Cooper S. I wasn't even doing anything nutty. Just pulling out of the driveway at work in 1st gear. Didn't even have the clutch all the way out yet, and POP! Stumble stumble stumble... F*CK.
Long story short, threads are pulled. I'll have to helicoil it, which won't be easy with the head on the car. But pulling the intercooler, supercharger, intake manifold, valve cover, timing chain and head to fix it isn't easy either. I looked on the internet while waiting for a tow and found numerous stories of this happening to other people. Sounds to me like poor metal quality. Really no excuse for that. Rant over.
Mark D.

That sucks!

Well, it blows, rather. But you know what I mean. :-/

Sorry to hear
Are the plugs recessed deep into the heads?
I have repaired the plug threads on a few heads over the years and if you can find a kit use a timesert they work better in my opinion.

I have wondered how the Chrysler/Rover designed engines would hold up long term.
Now the BMW move to a joint Peugeot/BMW engine makes more sense, maybe

Jim

Yes. It's overhead cam, so it's buried pretty deep down in there. I'm gonna hope somebody makes a Helicoil/Timesert kit to handle such a situation.
I commute 45 miles each way, so over the life of the car (loan, actually) I'll find out how well the Chrysler joint venture worked... Unless I get fed up and chuck it. I like the car, but have had a couple things that concern me. The clutch is making disturbing noises as well.
Mark D.
:EDIT: I bought the car less than a year ago with 31k miles on it. It now has about 55k.

Exact same thing happened to my mom's car a couple months ago. After reading up on it on some of the Cooper forums, apparently its pretty common. Once you get it fixed (her's was $2300 at the shop) make sure you put torquing the spark plugs every 10,000 miles or so on the maintenance list. They work their way loose and that is what causes it.

Yup. I put an insert in today. Hopefully it holds. I can see why it blew by tapping the whole. Tapped way to easy! Anyways, I changed the plugs while I was at it and the others were scary loose.
Mark D.

Sorry to hear that. I never thought about it but there alot of pressure on the plugs under compression.

Clow

I'm sorry to hear of the damage, but I appreciate the heads up. My wife drives an 05 S as her DD. It just rolled 70kmi, but I've not ever checked the plugs. I WILL NOW! I've got manuals if you need any specifics.

Double check the torque specs, I know it isn't much which is one of the contributors to the problem but you can easily do damage if you go too much higher.

I did the same thing on my old ford lightning, but I was doing something stupid, still beat the camaro though... But it sounded like crap!

Ended up being a flaw in the casting, got the dealer to cover a timesert ,but not for a new alum head....

Actually, if you could get me a torque spec out of your manual, that'd be great! Thanks.
Mark D.

Spark plugs (ungreased)
M14 x 1.25 27 Nm (19.9 ft/lbs)

Jim