Ok so considering I often find myself stumbling upon this site when I google issues with my R53 I figured I would make a post to help others like me in the future.

Driving my R53 down the highway one day when I all of the sudden hear a clank like something fell off the car and then right after the car barely is running so I pull right over to see whats going on. No smoke anywhere, I pop the hood. At first nothing looks out of the ordinary then I noticed it, cyl #2 's plug wire just tangling out! I look down the hole, NO PLUG! on top of that I can tell the spark plug seat was blown out! I am baffled, text my bud who is a Mercedes tech, tells me he has never heard of that happening. So I get a tow home. Now I do 90% of my own wrenching so I started researching fixes and came across this kit called a TIME-SERT, basically like a helicoil but better designed and stronger. The spark plug kit was $200 on amazon. Its a VERy nice tool set. I was nervous as all hell grinding into the cycl head of the car but I had no options. I didnt have the cash or time for a new head install and I called the somewhat local Greasy's Garage who said it was $250 for a helicoil and the head may crack....wtf....so before I get to work with the kit I buy all new plugs because they were some weird Brisk plugs installed by the PO, I went with OE NGKs for the JCW (modded r53). When I pulled out the other wires 3/4 holes were FILLED with oil. The grommets on the valve cover were prob **** leaking oil in, my theory was the oil slowly worked its way in the hole and that couple with pressure and a poorly torqued spark plug caused my issue. So I ordered four new grommets and a new valve cover gasket along with all new bolts for the valve cover. Replacing the gasket and grommets was pretty easy I followed the tutorials on Pelican Part's site and ordered the parts from them and way. Actually using the TIME-SERT kit was pretty easy, instructions are clear, I used a ton of grease to catch shavings and took my time, triple checking my every move. I then put in the new plugs and measured teh depth of an unaffected hole with that of the repaired hole to be sure the plug was seated at the correct depth, it was spot on!

I used a torque wrench to torque the new plugs to spec, cleaned up the Magnecor wires added to dielectric grease to the ends and put it all back. The car runs like a dream. I think I needed new plugs. I also took a minute to clean my PVC with degreaser then spray it with WD40 and it actually clicks now probably didnt help my weepy gaskets.

Sorry for the ramble I just wanted to put something out on the interweb so if this happened to someone else you dont see $$$$$ in your head, if my gaskets were fine and I just needed to use the TIME SERT to rethread and install a new insert it would have been a 60min repair tops.

 

Mine did this on cylinder 1 and I also used a Time-Sert. Even tho I'm a mechanic, the procedure can be a bit scary as it takes quite a bit of material out. It's been running fine since then (2 years).

 

Yeah it does, my bud who is a fairly experienced tech at Mercedes said he didnt think he would even try it himself because he would be nervous LOL, when I called the MINI specialty shop and the local reliable mech they both didnt sound so sure of themselves I felt like Hell I cant trust someone to try it who is not confident. Then looking online thsi seems to happen a lot to Fords.