I have seen this problem on this site before, but now it has happened to me. Just got on the freeway,shifted into third and a pop! Sounded like the exhaust became uncorked. I had it towed to the dealership and was told the #2 spark plug was sitting on the heat shield. After further checking I was told the threads were stripped. You know where this is going next. The dealership started blaming every mod on the car. My stats: 02MCS, Alta CAI, Alta Pulley 15%, Alta crank pulley 2%, Densos, 9mm Kingbornes, Borla Exhaust. The usual mods. After arguing with everyone including North American BMW I was told that because I had did not have the original spark plugs it was assumed that whoever put them in stripped the threads. Bottom line, they won't cover it. Now I either have to have the plug heli-coiled or replace the head. Either way I am looking at a repair bill over a grand!! Totally disgusted with Bmw. Seems they just keep looking for excuses not to cover under warranty even though it is still covered.

 

In my life, I will never understand this philosophy....

Let me get this straight.

You buy a car and mod it, knowing good and well that it can and will void your warranty. Then you have a problem with plugs that were not original to the car in the first place and you want BMW/MINI to PAY for it? I'm sorry, but I stand behind BMW/MINI on this one. You replaced the plugs and it is a possibility that someone or you over or under torque them. In this case, why should BMW have to pay for a mistake not made by them? This is all you, good luck.

 

they are spark plugs, they just dont blow ot of the hole.


over torqued or not, ive never seen a spark plug blow out of the head as many times as i have with these things.

helicoil it yourself. its not too bad of a job, but you may have to yank the head to do it, idk where those metal chips might fall if you do it with the head on. you might just be able to get away with changing the oil after drilling and tapping instead of yanking the head off.

 

interesting. randy webb at webbmotorsports.com talked about that issue at a pulley party i attended--the alloys used in the earlier mini heads were prone to spark plug blow out. (there was a problem with the actual chemistry of the alloy)... getting a new head will obviously solve the issue. (check out a after market head that way you'll get even more out of your mods)

 

that sounds like a plan to me! go for it!

 

I replaced my rotors with drilled / slotted rotors and brake pads with Greenstuff on my '05 MCSC.

Can I expect that the convertible top on my car is under warranty? Yes.
How about the supercharger in my car? Yes.

Can I expect that the new rotors and brake pads are still under warranty? No.

Sorry, but I don't think you have much of a case with your spark plugs...

 

The plugs you were using...iridiums, recommended by some and I have used them myself perform well enough but are more fragile than most and can come apart with high head pressures...trust me. I know this does'nt reaally have to do with the threads stripping out but I definatley would consider a different plug next time. Just my .02

 

Actually, yes they can. I had a 69 bug that had this issue when I bored out the engine and installed dual Delortos and an over sized oilsump. The plug was overtighteded and the threads gave. Anytime you mode a engine off of the base you take a risk. Either way, all comments made have been for him to resolve it himself with either a new head or the heli coil, not beat up BMW/MINI for his problem. Everytime someone does somthing like this the cost is passed on to the comsumer... So you really want to pay for his misatake?

 

I just had this happen to me last Thursday; the exact same events occurred right down to the same cylinder. My motor is set up similarly; a 15% underdrive and the Denso plugs. I am out of warantee anyway, but you don't have a leg to stand on when it comes to BMW covering this work; you modified the car and BMW didn't. From their standpoint, this is a no brainer.

The threads are pretty much gone; it looks as if the plug backed itself out until the last thread or so, then the compression blew it out the rest of the way. I am having a heli-coil put in my head as we speak. I am not happy about this outcome, as this is a half-assed fix and will eventually detonate also; however the only other fix is a new head and we all know this is pricey. My concerns about this approach are that now there will be a random chunk of steel in an aluminium head, and it is very difficult to determine the depth at which the helicoil is installed...so the plug most likely won't sit where BMW designed it to.

The worst part about this is I knew I should have checked the torque on the plugs but was waiting until I had an entire weekend for some MINI maintenance; I guess this one really backfired.

Over $1K either way? I dunno about that....the work to install a helicoil should not approach this figure.

 

I'm willing to bet that the coil will outlast your other threads... I have been using them for a long time on various things (roller skates to aircraft and cars) and have never had a problem. In most cases they are as strong or stronger than the original threads.

However, you should have them remove the head to do this. Even a little metal could ruin your engine.

 

Hmmm....well the shop is trying to do this w/ the head on. I asked them about the metal chips and they offered two remedies for this:
1) use grease / lubrication which will trap the metal chips, then clean area to remove
2) compressed air and vacuum out from cylinder.

At this point I don't know what stage the is in with this project. When they call next I will have another update; I think today is a holiday for them. I believe you're right though; the proper way to do this is head removal. Of course, that's also lots of time & money. ARG.

 

Well, you have to ask yourself... Do you want quick and easy, or do you want it done right. Good luck with this, I know a bill like that can be painful especially at this time of the year.

 

Confession time - this happened to me also, I believe it was also the #2 plug. BMW did not of course warranty the problem for the same reasons above but they only charged me about 125-150 for the heli-coil. If you are considering having them remove the head just to heli-coil it properly ya might just consider buying a new ported and polished head since you'll be paying all those labor charges.

I am saving up to do this myself.

 

Did Randy say when they fixed this problem or what "earlier heads" meant?

I have a Cooper S, September 02 build (2003 model year) and although I have not removed the plugs yet I intend to change them once I pass the 50,000 mark and was wondering...

Rich

 

|I agree with daflake on this,pay now,or pay later.:impatient Q

 

I kinda sympathize with crzycpr. Sparkplugs shouldn't just "blow out" their threads. I've been working on cars for a long time. That is just not acceptable. It is possible that the OEM sparkplugs were crossthreaded and that caused the weakening of that area. Besides, there's too much evidence that BMW has/had a known issue with poor/iproper materials with MINI cylinder heads.

FREE TIPS:

1. Don't remove a spark plug from an aluminum cylinder head unless it is COLD. If you do it hot, or even moderately warm, you can pull the threads right out of the head.
2. Steel screwed into aluminum sets up galvanic corrosion. Put it in at 20 ft-lb and you may need over 100 ft-lb of torque to remove it later on. USE ANTI-SEIZE when putting a steel fastener into aluminum. Let me repeat that for emphasis. USE ANTI-SEIZE when putting a steel fastener into aluminum!

I hope he eventually prevails.

Rawhyde

PS A Heli-Coil is a good repair. As a matter of fact, all aluminum cylinder heads sold by Edelbrock come with Heli-Coils from the factory. Don't worry about depth issues. The plug seats with a gasket ring. It'll be right when it bottoms out.

 

Don't get me wrong, I sympathize with him as well and I hope that some resolution comes of this. Perhpas BMW will pay half as they do have a slight history but this would only be as a gesture as it is not really their fault. Unfortunetly, the history that I have seen has always been modded cars running hotter plugs. I have yet to see someone that has not modded the vehicle complain of this and I have been lurking for sometime.

Either way, I hope he gets the car fixed.

 

well, he indicated that your build date would give you that answer all cars up to a certain could possiblly run into spark plug issues.. (spark plugs need to be torque to 20lbs and no more. ) i remember him saying that 04's to current dates are ok. 02 and some03's could have problems.. i'm not completely sure tho.. go to his web site. : www.webbmotorsports.com

he should be able to help. also, if you car is out of warranty just spend the $1800 for a new head/cam and have a good day.. (thats what i would do)

 

The unfortunate reality is that this is a head problem that Randy Webb has seen on primarily, if not strictly, '02's and early '03's... with stock plugs, and an assortment of aftermkt ones...

This is a BMW/MINI issue that they apparently don't want to fess-up to as they seem more than happy with their escape... 'you mod, it's your fault' mentality...

I had stock plugs loosen-up, and then my aftermkt ones. I now check every 6 or so weeks, and it angers me that I need to do so b/c of their short-comings; b/c if I don't, I might end-up as this poor guy, which really sucks.

crzycpr, there is some good info here on NAM, and on Webb's site documenting this issue with earlier MINI's. Randy would be happy to share more details with you as it would give you sufficient ammo to plead your case. Best of luck to you!

Add/Edit - I now use Anti-Seize (just a tab) and I'm finding that the plugs stay put a little better. I still don't find this acceptable, and feel that BMW/MINI should do the right thing, and rectify this problem. But, it would be a costly fix for them, so don't hold your breath...

 

Not over a grand!! Mine blew #1 and I had a heat cert (sp) put in and it was WAY less than a grand

Earl

 

While I've heard all about plugs blowing out of the holes this is the first I've heard of suspect alloy. Would anyone familiar with discussion/threads on topic care to list links?

If there is a correlation between early heads & plugs popping alloy or the #2 hole it would be good to document it for the community.

IMO it sounds suspect when several folks claim that the same plug (#2) is popping. Why should different folks have a common tendancy to over-torque the same plug/hole? ...Possible, but seems improbable.

Any of you who've suffered this want to start a thread or poll to document this?

Sugestions:
Model: MC/S
Production wk/yr
Plug that popped - make & which hole
plug torque - ft/lbs. or N/M & anti-seize or not

 

This is where Randy made a formal announcement about this concern almost 2 years ago:

http://store.webbmotorsports.com/for...opic.php?t=305

I recall a couple more threads in his forum where this topic came-up, and several here (NAM), one fairly recently by Dr Obnxs...

 

Hmm, I read the thread and I have a couple of comments.

1. As people had posted earlier, I assumed that Randy had done a white paper outlining the problem. What it seems is that he simply made a few comments in a thread, none which state that there is a problem with the actual head. He was very careful about that.

2. The majority of people having problems are using Denso plugs (there are a few other brands that he stated he saw loose but they were the majority that I have seen). Could it be that these plugs are not spec'd right and this is not a head problem?

3. Randy simply said to check and make sure that the torque is accurate so that this will not happen to you. He said nothing about beating up BMW/MINI about it.

Here are my thoughts....

It is a possibility that BMW/MINI did have a problem with the head early on ONLY if hotter plugs were used. Hopefully they have increased the tolerances over the years to compensate for this. The original head may have had a low tolerance and by moving to hotter plugs and putting more pressure on the head, it may cause this problem. However, we have to remember that BMW/MINI is only responsible for FACTORY level performance. So, if they continually test heads and have no problems, they are not going to send out a recall. However, they may increase the tolerance during the next production to keep repairs down but only because it looks bad to others when things like this happen.

Welcome to marketing 101....

In the old days, one of the first things that we used to look at replacing was the factory head during mods. Today, people just want to plug up all the easy gadgets to get the power. Yes, the head should be able to handle it to a degree, but putting a performace head on there would have kept this from happening all together. Oh, but wait…. It doesn’t give me a big HP increase, so why do it? Well, it will give you a performance increase as the engine can better handle what you are pushing it to do.

Am I the only one that feels this way or am I just old and set in my ways?

 

I agree w/ Daflake; BMW isn't truly at fault. However, the JCW motors make the same sort of power mine does; do these blow out too? Or are they a different head design?

I have re-thought the issue; I'm going to need to remove the head to do the work correctly. I typically do all my own automotive related work anyways, with the exception of things requiring crazy tools; balacing, alignments, machining, etc. Removing the head is not rocket science.

I have questions for those with more engine work experience:
1) I have not ever ventured to put a helicoil in a spark plug recess on a head before. Leave this to the pros?
2) The mention was made to put anti-seize between the still-intact threads and the plugs, and I will be sure to do this in the future. What material should help seat the heli-coil in the aluminum head? Loctite RED (266 I think?) Recommendations please.

Also, someone up the chain here recommended to just buy a new head & install. Does anyone know what was changed in the design to prevent this failure mode? Will buying a new head really fix the problem?

Thanks everyone;

 

I truly think that what is causing the problem is the heat generated by the plugs. The JCW kit gets a different head, not the stock Cooper S head. So, the tolerance is different. It is designed for performance.

I learned how to do heli-coils when I was a teenager working at a roller rink. It is not hard, but you can screw it up if you are not careful. My advice is to take it to a shop. It should be much cheaper than a new head install. However, if you plan on mods, a performance head will save you some headaches in the future and you might gain some power out of it.

Anti-seize compound will keep the plug threads from corroding to the head; it does nothing from keeping them from backing off. Proper torque is what does this. DO NOT USE ANY LOCKTITE.... Putting any locktite could cause more problems later as loctite is like gluing the plugs in.