No, there isn't one, unless you consider not retorquing your spark plugs occasionally...

The other day, as I was starting my 03 S with 75k miles, I heard a POP from under the bonnet, then smoke. I opened the bonnet to a waterfall of fluid (gas?), and saw my spark plug, still connected to the wire, laying on top of the head.

The spark plug has been ejected from the head, stripping the threads, and causing me to hyperventilate. I tried to rethread it, but it just turned in place. I checked the others and 2 were slightly loose, and the #4 was almost all the way above the threads.

It seems that a number of aftermarket guys (Randy) have posted service bulletins of one type or another for years, but without knowing that there was an issue with this you would never look for such a publication.

Obviously, I am out of warranty (doesn't matter anyway with all my mods), so I got a quote for a new head - $4300 installed. Ugh. I asked about Helicoil and the dealer said 'no'.

So my buddy has done a few rethreads on aluminum heads, and in a half hour, for $3.31 (the cost of the insert) I was fixed. I used the NapaPro insert kit, but I understand Helicoil is great too.

2 things - a spark plug that works it's way out of the head? You have to be kidding. And MINI won't recognize the problem? Perfect. Good thing I was in my driveway when it happened.

So - TORQUE YOUR PLUGS to 20 lbs. Do it now - it's not that difficult and takes very little time. I was lucky that I could rethread my head, but blow a plug out at 80mph (um, I mean 65) and then what happens? Oy.

 

Oh man that sucks! Were these the stock spark plugs (originals with 75K on them?) or others that were installed aftermarket? If not stock, which brand?

Great news, though, that it only costs $3.31 and 30 minutes time to fix (versus $4,300 for a new head!)

-boognish

 

What brand of spark plugs did you use ?

The original NGK or aftermarket plugs ? Over here in Germany we have this problem too, but most time with aftermarket plugs from Beru. As far as I know no NGK has come loose right know (but I might be false).

I check my plugs every oil-service, mostly because I do not wanna rip my larger intercooler apart.

 

These were my third set. I replaced the first set with Densos when I installed the pulley. Those fouled after about 30k so I replaced them with Bosch Platinum 2 element plugs. The #3 Bosch plug was the one ejected.

From the posts I have read in the past few days, this is a metallurgical issue with 02-03 heads. It was corrected in 04 and later heads, but the part number is exactly the same...

The moral is - check your plugs. And DON"T over torque them. You should have seen how EASY it was to tap the aluminium head... like BUTTAH.

 

I would also question the pully you mention. Your Mini might not be up to the increase in compression pressure.

 

This is actually fairly common with all aluminum heads. Has to do with expansion contraction. I had it happen going down the road at 70mph. It was noisy and messy. I did the threaded insert thing and have had no problems since.

 

Do you think they would have coverd this issue with stock car with stock plugs?