My #1 plug blew out while I was letting my wife drive my car last week. She had a buddy come over and he got the plug reinstalled somehow. I drove the car for a week and then my #2 spark plug popped out. I replaced these with NGK BKR6ETX Iridium about 2 years ago. The plugs seemed to burn better and I increased my milage by 3 miles a gallon.

Not sure what to do now. I am worried about the metal shavings from the blown out threads inside the cylinder. Should I remove my head and get them out? Is there a small vaccum device I can get to suck them all up? Or did they all blow up the shaft when the spark plug blew off?

I removed my plug from the #1 cylinder that my buddy fixed and now I can't get a new plug in there. It looks like all but one or two threads were still on the #1 cylinder and removing the spark plug removed them too. Now I have no threads at all on my #1 spark plug.

I have head Helicoil is an option, and also Time Sert. Which one is better?

Also, I am a little ticked. I have never heard of this. I would think the wearker part should be the plug, not the Head. Isn't this a manufacturor defect?

 

Even if your car was under warranty this wouldn't be covered. You aren't using the recommended plugs. You are using a plug that is known to cause this exact problem.

I'd call it operator error before calling it a manufacturers defect.

 

Helicoils work fine, they were developed in WWII for this type repair on Radial Aircraft engines. Lube the plugs start them by hand and torque to spec. 20-22ft lbs. Locktite is NOT recommended on Helicoils, just retorque the plugs at oil changes.

 

I was actually just going to purchase a set of Brisk plugs for the car, but now after reading this I think i will just let the dealer change them out on the next oil change. This is the first time in 30 years i have heard of blowing plugs out.

 

Don't forget, the original MINI engines come from a joint-venture BMW/Mopar plant in Brazil. Do the heads come from there too? I am willing to bet BMW didn't invest 1 penny more than they had to to get these cars past their warranty period before they begin to self destruct.

 

We have been dealing with this problem for a long time. Helicoils work. There is a tool called a BackTap that also works without taking the head off. It cuts new threads from the bottom up. I did it for a friend and it worked nicely.

That said the heads are aluminum and the plugs are steel and the head threads WILL give before the plug. I do not believe that the brand of plug makes a difference. My experience with Denso's is that I installed them in the head first thing in the morning when the head was stone cold. A bit of anti-seize on the threads and dielectric grease in the boot and torqued to 20 pounds. I check them (also with cold head) every 5000 miles when I change the oil and have not had a problem now in over 60,000 miles and two sets of plugs.

Just my thoughts.

Rich

 

I have not had mine out yet, car has 58 K on it. I have changed alot of plugs in my day and never had a problem. I will take your advise on how to do it in the AM and see how it goes.

 

I see quite a few people in this thread have recommended using anti-seize. But since anti-seize is effectively a lubricant, what torque value do you use for this? Dry torque values are not the same as wet torque values.

 

Me too. But when I started hearing about plugs shooting out of cylinder 2 I started paying attention. I can figure why one plug would be problematic and others were not but anecdotally it did look like the Denso plugs were more prone to liftoff but the plug threads I fixed for a friend were stock plugs and they were not torqued in at all. He only put them in "as tight as he always did".

But we are not talking small block chevy heads here and if the aluminum is soft in any way I just figured cold was better and proper torque and anti-seize made sense. And it is now around 70,000 miles on two pairs of Denso's for me with no problem what-so-ever and at each 5,000 mile check none were ever loose.

Rich

 

Bump (better thread than the newer one )

My #3 popped out today - leaving a traffic light / turning left, BANG!! bap-bap-bap-bap-bap-bap... - the boot was laying flat on the valvecover, the plug was under the intercooler. Limped it home on 3 cylinders (~2 miles) along 35mph roads, only issues being the noise and the CEL.

Had a set of BKR7EIX-11 in for about 2 years, a couple of times I had #4 ~1/2 turn loose.

I let it cool down some, retrieved the plug - threads were good but white-ish - no debris noted in tube, slight bending damage of the plug wire boot fixed w/ a phillips screwdriver (MSD Super Conductor wires). Tried reinstalling the plug, got it to hand-tighten once, then came up w/ the brilliant idea of pulling them all and (since they were all intact, gapped the same, and the same color) swapping 1-2 and 3-4. Couldn't get the previous #4 plug to start in the #3 hole (~10 minutes), then couldn't get the #3 plug to start in there, either .

On a hunch, I go in and dig out my previous Platinum +4 (that I almost tossed a couple of weeks ago) to give then a try and in they go like the previous stuff never happened. Threaded fine, tightened fine, started right up, no bap-bap noise, up and down the road, and, what the heck, how 'bout a high-rpm downshift to slow before turning onto my (private) road. Hey, if it's gonna pop again I'd prefer it be w/in coasting distance of my driveway. Re-checked plugs, all were tight (but not torqued - new adaptor tomorrow), everything good - just gotta reset the CEL...

So the Iridiums wouldn't go back in (#3), but the Platinums would - and both NGK - Hmmm...

 

If the threads end up blowing, I have a mint condition Time-Sert kit for sale.

 

Even though the threads on the iridium's look good they could be borked just a bit. Combine that with a slight bork of the threads in the head & that may explain the plugs no-go into the head. Since you can get other plugs in there you may have dodged a bullet. FWIW I check plug torque at every oil change.

Good luck!

 

So I went for another drive yesterday, similar to the previous day's - had to get a 1/2 to 3/8 adaptor for the torque wrench to plug socket, as if I needed an excuse - but checked the plugs cold before leaving (the P+4's); the #3 needed snugged down a little (hmmm), but the drive was uneventful (except noted the CEL was out).

Went out this AM and torqued the plugs (20? 22? 25? >> I went w/ 23). #3 again seemed a touch un-snug (loose isn't the right descripter), but that could've been a little bit of caution on my part in case the threads in the head were "borked" (thanks to Crashton for the new technical phrase). I'll save evaluation until I put some miles (and a couple hot/cold cycles) on it ...

thanks

 

... So, 700+ miles later (still on the +4's), and no issues, other than the paranoia about #3 coming loose again. A couple of times I've re-torqued it (23 ft/lb.s) and checked the rest; now seems to have stabilized.

"Crashton", I agree: I think the Iridium's threads were 'borked' and that's why they wouldn't re-thread. The root cause was the plug getting so loose that there wasn't enough threads to hold against the cylinder pressure - i.e.: me falling down on the job in regards to maintenence I didn't previously know was recommended (do now!)

I'm gonna put in another set of BRK7EIX-11 when I do my pre-season maintenence (as in pre-event-season) and keep the +4's handy just in case - will now remember to keep an eye (and torque wrench) on them. Still the first time in 35 years of screwing around w/ cars I've heard of torquing plugs, but ...

 

Just blew out an OEM plug at 91,000. Got quoted by MINI dealer possibly $2500 to repair including new coil pack if they can use the old head. They say that the plug took the threads with it. If they need to use a new head, the cost will be much higher.

I've never touched the plugs on this car, but when the car had 39,000 miles on it, the engine quit running a few times. It would just stall and not come back to life. Took it to the dealer and they told me that the head at the time had been improperly machined at the factory and that they'd sent it out to be remachined to within correct tolerances and reassembled the head. This repair was done under warranty.

52,000 miles later and I'm driving along and BANG! and sounds like a jackhammer underneath my hood. No spark plug flying out anywhere--visual inspection showed no damage. I hadn't been paying attention to MINI forums or I'd might have known. It did sound to me, though, exactly like when a friend's spark plug came loose in a Toyota twenty years ago, but that car had regular spark plug wires and a distributor, and I could see the plug dancing around. Tightened it up and all was well.

Anyway, that sounds like a lot of money to me. I told the rep that the only people who have touched that engine is MINI and that it sounds to me like the plug was probably overtorqued or installed into a hot head. However, since I can't prove that I didn't monkey around with the plug, I'd be willing, hopefully, to negotiate--maybe 50%. The car is out of warranty, but two head jobs in under 100,000 miles where the car has not been abused at all is just not acceptable.

I've owned the worst of the worst cars in my past based on Consumer Reports and public opinion (Yugo, Renault Alliance, Renault LeCar) and none of them ever did the oddball and yet expensive things that this car has. They all went well over 200,00 miles easily with minimal problems and you could throw whatever plug you wanted to in them. I still have the Yugo and it's got 275,000 miles on it--a number that I doubt my MINI will make, though, if the MINI does die, the seats will look great in the Yugo. Plus, the Yugo has done that for $3995 and maybe another thousand or two over twenty years in regular maintenance costs.

To me, if the dealer is blaming aftermarket plugs for this problem, you know, it's really disingenuous. It may be that the aftermarket plugs merely expedite the process of damage to a poorly made/designed head to begin with, but come on, if I can put any plug I want to in a Yugo or a Renault for Chrissakes, why not a MINI? It's just bad engineering. Is it wrong of me to expect that a car that I paid so much money for outperform a Yugo or a 1980's era wet-sleeve Renault in terms of maintenance, particularly when both the Yugo and the Renault Alliance were abused by being used to deliver pizzas when I was in college on, basically, cobblestone roads that killed Hondas, Mazdas, Mitsubishis and one Volvo? This MINI has pretty much only coasted along on the smooth freeway its whole life . . .

And, I didn't put in aftermarket plugs. Mine were stock plugs. The car had no mods. I am the original owner and I've babied this thing. I've beaten the crap out of my Renaults and Yugos and I've never had nonsense like this happen even once and now twice.

I think that once we start seeing more MINIs with higher miles on them, we're going to see more OEM spark plug blow outs as the alloy fatigues.

Does anyone know if there's an aftermarket head available that's built with reasonable expectations of quality?

Should I ask the dealer to Heli-Coil all spark plug holes top and bottom as long as the head is off anyway?

Doesn't $2500 sound like a bit much?

If I didn't love this car so much, I'd really be considering replacing it. Of course, I always love my cars--except maybe for that Plymouth Breeze, and even that wasn't a bad car. It was really quite good, just no fun.

Sorry in advance to anyone I may have offended for comparing the MINI to a Yugo and a couple of Renaults, but, I'm speaking from personal experience. I do realize those cars are built to a totally different purpose, but, really, can't use an aftermarket plug and the OEM plug will pop out and strip the threads at 91,000 and cause thousands of dollars in damage? Okay, so the Yugo is and the Renault was slow and neither got any respect, but they could hold their plugs . . .

Sounds a little like GM saying that you must keep the air pressure of the front tires of a Corvair at 20 psi.

Rant over.

 

ANY boostfed engine, turbo or supercharger, always runs the risk of shooting plugs out. I have a friend who had it happen in his Ford Lightning a few years back. However, the threads did not strip out.

Even if you were told the head was defective at 39K, if it's not in writing, there's no way to prove it. However, since the head was redone previously, you could go back to that issue. If they sent the head to an aftermarket shop, then that shop could be held liable. If you still have the receipt from that repair, go over it with a fine-tooth comb to find out what's to your advantage.

If the head is ruined, and they won't cover any or all of the cost (which many MINI dealerships will argue over), check this forum, as well as E-Bay, to find out if one is available. Mini Madness sells an aftermarket head for $1,099, but I'm not sure if they require a core return: http://www.mini-madness.com/madness-...nder-head.aspx.

 

JPLong - call a local independent shop and get a quote on a helicoil for the plug. A good shop can do it with the head in place. Should be much easier on the wallet. No sense tossing the head for a single plug thread.

 

I should get an update later today as to what all the damage is. I'd still rather the dealer to the repair work. Not sure why. I've always done all my repairs since I first started driving because one of the first times I took a car to the garage (Renault Alliance, driveshaft) I got totally screwed by an overpriced and incompetent mechanic (chief complaint of AMC mechanics working on Renaults) and this was also a dealer.

Couple more notes: I just have the regular Cooper, no supercharger, no turbo, no mods. It's still high compression, but . . . well, even if it was due to super compression, my Turbo Fuego never threw a plug, but I'll admit, that particular car didn't make it to 91,000 as gracefully as the MINI otherwise has. Perhaps you just trade issues.

The dealer's got a copy of the repair order, though, with the explanation of the work done on it, so I don't think that's going to be an issue.

Maybe I go to this dealer because I still trust them anyway, which, as I've already explained, is pretty difficult for me to do based on past experiences. I do feel like the guy's trying to work with me, so that gives the dealership a lot of credit. But, we'll have to see what the result is. If they don't work with me on price, which they don't have to, then I will get a quote from somewhere else or maybe actually attempt the job myself.

The guy across the street has a nice vertical drill press. I've got the factory and the Haynes repair manuals, which, hopefully, can make up for any lack of experience I have with this particular car. It's summertime . . .

But I'm supposed to be finally restoring and customizing that old Yugo, which includes a complete engine rebuild by yours truly. The MINI is supposed to be trouble free so that I can care for my classic oddball European beaters

Thanks for the link to MINI madness, Jack. What's another grand when the shop might charge $300 to install a $2 Heli-Coil? Though, will a head for an S fit on a Cooper? I never really looked at the specs for an S. Is it the same engine/head just with a supercharger installed?

Another question: if they do take the head off, why not get it polished and ported while it's off? I never really thought of modding this car because as an oldster, all the computer software stuff sort of seems like a hassle to me. I grew up in the days when parts bolted in and that was that. But seems like an opportunity has just presented itself.

 

These people are trying to rip you off, Like Eric said you don't have to remove the head to install a spark plug helicoil.

 

The difference between the heads is the "S" has Inconel valves, think of it as high temp nickel based alloy.

 

I don't know. Seems like the right way to do it to me as opposed to the wrong way. How do you know if you've gotten all the metal shavings? How do you install one on the underside as well unless you take the head off?

It seems pretty straightforward, though, and I have done it with other cars when friends had cross-threaded or overtorqued.

I guess I'm feeling afraid of this head because it's obviously so soft.

We'll see what the final quote is and then I'll decide what to do about it myself.

Thanks for all the help, guys. I still owe $7k on this think and I've been looking forward to paying it off, not take on new debt.

 

Just a note about the dealer quote: I'm reasonably certain that MINI (BMW) would not allow repair to a head like a helicoil or time-cert based on the potential for liability - the estimate should be for a replacement. Just a 2 cents perspective...That said, $2500 for a popped plug? For an out-of-warranty car, I'd be shopping around hard...Bummer on your luck, hope it gets better...

 

Personally I would not use a Helicoil. Why worry about it backing out, threads getting stripped again, etc? I would either use a Time-Sert or replace the head. PM me for more info.

 

Yeah man, just go ahead and replace the head. Used heads pop up on the marketplace all the time for a few hundred bucks. Send it to a machine shop have them clean it and pressure test it and throw it back in your car like nothing every happened. I'm in total agreement with you in regards to spark plug torquing. To me its just inexcusable, but most people on here seem to accept it. Dont know why? Maybe they dont know any better. Eh, I've got a Toyota Tacoma with 175K on it....had it since 85K, replaced the plugs three times for maintenance, never once torqued them and they are as tight the day I take them out as the day I put them in. But IMHO my toyota is built a million times better than this silly Mini. Unfortunately like you I LOVE my car and really couldn't bare to part with it, so I too put up with its uncertainty and unreliablility and rant to whoever will listen!! LOL

Steve