On my way home from work I blew the #2 spark plug straight out the engine. Gotta get the hole re-threaded.

What would cause this? Mods in sig.

 

Not tourquing the plugs with a tourqe wrench when installed...should be done into a COLD head.
some plugs like denso's seem to have this happen more, but has happen to every type i think...
The soarkplugs have a onetime use crush washer...it feels like it is thight when you tighten up against it...but it is not crushed yet...so many folks stop tightening ...so the heat and combustion preasures and vibration slowly loosen the plug till WAM!!

 

Repeated over tightening is also a possibility or just taking the plugs in and out excessively.

 

I've been told there's no compression on #2. I'm getting ready to have to **** out a lot of dough, correct? The plugs haven't been touched since I had the mods done just over a year ago.

 

Im guessing if you had the plug blow out most of the threads are gone. If so, how are you getting a compression test done?

I've used the TimeSert on my F350, great tool and very straight forward.

Nik

 

Talked to Sneed's (did the mods) and said it's a common problem with MINI heads and the casting at the #2 spark plug. Should I get a performance head upgrade? I've not read about this problem on here before.

 

I wouldn't at this point, unless I was looking for an excuse to get a new head. I would re thread and go on my way, just check the torque regularly. I've had no problems with plugs in over 298k, running more mods than you are running.

Nik

 

It is common and there are lots of threads on it, just do a search. Timesert and be done with it, that simple.

 

Did the same thing to mine, but on cylinder 1. I've used a TimeSert, it's pretty scary as it takes quite a bit of aluminium out. I filled it with grease and did a couple passes before going thru completly and remove as much shavings as possible. Then used a shopvac with a small plastic hose to get anything that could be sitting on top of the piston. It can be done without removing the head, but you have to be careful. Couple thousands kilometers later and a couple days of track and it's still holding. I prefer the TimeSert over the usual helicoil, as the Timesert is a sleeve, rather than a stupid spring.

 

Had it happen to me on my 04 JustaCooper. Timesert and ran great. My mechanic did it and as I recall it ran about $400 installed.

 

Thanks for the replies y'all.

Soooo, from what I'm hearing/reading, I can just chalk this one up to bad luck/shtuff happens? I guess this doesn't happen enough to have had a recall on it, huh?

 

Recall.....lol...user error...soft aluminum threads, chrome plated steel threads on a sparkplug...if one is over or undertighting ANYTIME in the heads history...bang it can happen.
just seems to happen on a mini lots, my guess is lots of first timers, combined with combustion pressures....

 

Hold on there I think the Mini heads are just being ******* I've done my share of spark plugs changes and I never had this happening. I do have to plead guilty about the torquing, I just do it like any other cars, 3/8 wrench and a slight turn once it's seated. But believe me, next time I replace them, I will use a torque wrench, I wasn't that excited about the amount of aluminium that is removed with the Timesert.

And there's also the fact that I'll be screwed when I'll buy a BVH, won't be able to send my head as a core (most companies don't accept cores with helicoils).

 

Talk to Thumper, your head may still be good.

 

Well, the MINI's at Sneeds now...... hopefully I'll find out tomorrow what my options are. Want my baby back....... ribs.

 

Soo.... progress is finally being made! Apparently the O-ring that seals the head to the block was slowly going bad and leaked coolant into the #2 cylinder, which it tried to compress and so it blew out the spark plug. The temp was high enough to melt the spark plug and get metal in the exhaust valve.

Re-built head going on at Sneeds........

 

Making LEMONADE!! When given lemons....
Sucks it broke...but it will be SOOO much better when done (if going to sneeds I suspect you are getting just a bit more than a basic rebuild)!!
Interesting failure mode though....guess as these cars age we might see more "odd" failures!

 

I hope in time for MOTD...... or should I not push it that soon?

 

Seems reasonable to me to have it done in that time.

 

It's the audio mods.... Gets you every time.

 

I have made a spark plug torque check part of my oil change service. Haven't found one loose yet. I have found piece of mind knowing a plug isn't going to blow out.

 

if that is the case you should have noticed some white smoke out the back of your car before this happened. In reality it is steam as its water vapor. My guess is head gasket went, you were burning the coolant as you drove (possibly at night and you did not see it.) As it sat over night more coolant leaked into the cylinder. Somehow the car actually turned over and attempted to compress the water in the cylinder and kaboom. normally its known as hydrolock, but in your case it went kaboom instead of "seizing" the motor to a stop.