Bitch Kitty Racing

The Mini Cooper S suffers from a well-documented problem, one which results in an occasional knocking noise in the front end when turning or going over bumps. What is it? Well, my own car was making this noise so I took it to my dealer, Northwest Mini, where Steve the service technician got into my car for a ride. “I hope this isn’t a wild goose chase,” he said. “It’s Friday and I have a lot of work backed up.” Steve apparently had better things to do than address my concerns.

After a ten minute ride the noise still hadn’t appeared. Steve seemed vindicated and got out of my car with an invitation to bring it back for a check if the noise popped up again. “But what am I supposed to do in the meantime?” I asked. “There’s something wrong with my car or it wouldn’t be making that noise at all.”

“Drive it until it breaks,” said Steve. “We’ll find the problem then.”

As I drove away I had the feeling that I’d just been completely dismissed by someone with more knowledge than me, like the feeling I used to get when my old plumber would adopt a haughty tone and started telling me about pipes and seals and flux and about how this was going to go over estimate, sorry.

I fired that plumber. He wasn’t the only game in town. My new plumber is the kind of guy who takes joy in ripping out old pipes with a sawzall and generally creating huge messes. He’s a kid with power tools. In the middle of the mess he’ll call out, “Hey John? I’ve found the problem!” And then he’ll show me what is wrong, why it failed, and what he’s going to do about it. He takes pride in fixing the problem, not just repairing it. I have no doubt that he knows what he’s doing because he very clearly explains it to me in language I will understand. When I get the bill I know why I’m paying it.

And so I fired Mini Dealer Service.

I admit I’m partly to blame for not immediately going to the service manager and explaining what happened, giving him a chance to make the situation right. I’m sure he would have dealt with Steve (or at least re-trained him in customer service) and given me another tech. Mini service is usually excellent. But then again, I expected the service to be right the first time.

I do not drive very often. An average month will see me put maybe 400 miles on my beloved car. As I drove away from the dealership I decided to live with the noise and see what transpired; maybe Steve was right, the problem would get bad enough to be more easily diagnosed and repaired. The service manager, Terry, had assured me when I reported the problem the first time (yes, dealing with Steve was the second attempt at fixing this) that, because the problem was reported under warranty, it would be dealt with under warranty.

On the way home I had to drive on I-5, a nightmare of construction, ruts, cracks, and holes, i.e: a normal road. The Mini made the noise immediately after getting on the freeway, and popped along cheerily all the way home. (For reasons known only to themselves, Mini opened up their dealership in Tacoma, thirty traffic-choked miles south of Seattle, the major population center of the Pacific Northwest.) By the time I got home I realized I didn’t entirely trust the car anymore. It had a weak point, or it wouldn’t be making any noise at all. It’s a newer car and newer cars do not make strange noises.

So for the last year I have been enjoying my car less. I do not want to drive it hard for fear that something will fail catastrophically, and I bought it because it is a joy to drive hard. MiniUSA published an enitre section on their website on competition autocrossing, so I must assume they endorse hard driving. My joy is gone. The car needs new tires, badly at this point, but I was holding off until I found out what was wrong. Why ruin a set of tires on a front end that moves around disordedly? If it wasn’t moving around disorderedly there would be no noise.

Oil change time, almost one year later. Luckily enough I ran into a college buddy who worked at a high-end shop, the kind that never advertises based on price, but on service. They keep records on your car and care for it better than the dealer—that’s their competetive advantage. They work to foster a long relationship with the customer. Come to think of it, they remind me very much of my vet.

My new mechanic, Eric, was at the Vehicle Research Institute with me at Western Washington University. I trust him implicitly because he’s another car guy with a Bachelor of Science in Vehicle Design, and we also worked on the same race team. He’s also a kid with toys. I asked him about the noise.

“I’ll look into it,” he said.

I picked up my baby the next day, washed, polished, and cared for. Eric showed me the Mini Service Bulletin that covered my noise. May I restate that? Mini has published the symptoms and the cause. This information is available to all those with access to Mini Service Bulletins, like, say, a Mini dealership.

!!!

The noise is caused by a mushroomed strut tower crown, a very common problem with these tightly-sprung little cars. Let me see if I’m as good as my plumber at explaining it:

I want you to flap one hand. Just relax your wrist and FLAP FLAP FLAP. That’s your car’s spring. Now go stick your hand in a bathtub filled with water and flap it again. It’s harder, isn’t it? The full range of motion is still there, but it is dampened by the water. I’m going to Hell for that pun, but the water is your car’s motion dampeners, be they called struts or shock absorbers. They allow the movement of the spring but do not allow it to be so violent that your car hops off the road.

Now imaging flapping your hand in a coffee can filled with water. The motion is still dampened, but you’re rapping your knuckles on the sides of the can. The range of motion is limited by the sides of the can. If you really tried hard enough you could actually hit the can hard enough to bend it, so your car is designed to absorb this impact with bump stops that distribute the force over a large surface area so there is no bending.

Imagine holding a coffee cup upside down with a pencil in it. The pencil is the dampener (strut, in this case), the eraser is the bump stop, and the coffee cup is the strut tower crown. Tap the bottom of the pencil and the eraser deforms a little to spread the impact over a larger surface area so the cup doesn’t break. If you used something like a screwdriver with a very fine point the cup would shatter.

In the Mini Cooper S, the range of motion in the suspension is very limited to improve handling. Imagine dropping an egg onto pavement. It breaks. Now drop the egg onto a piece of foam from the same height. The foam has to be thick enough or dense enough to cushion the fall or the egg will break. The egg is our strut tower crown, and the foam is our springs (and also, to a lesser degree, our struts). The thickness of the foam is our range of motion. If the foam were of a very dense variety, it could be thinner and still cushion the egg.

The Mini Cooper S has a thin but dense foam, but it is not enough to fully cushion the egg. At full compression of the springs and dampeners, the bounding motion of the wheel is absorbed by the the strut tower crown. The strut tower crown has to be strong and tough enough to take the impact—there’s nowhere else for the impact to go. The Mini Cooper S does not have strong enough strut tower crowns and they are notorious for mushrooming.

Now let me tell you about the suggested repair: I called Northwest Mini and the service technician told me he’d pound the strut tower crown back in shape with a piece of wood, and that it would probably cost me $600.

What?!

Do you know how to break a wire? You bend it back and forth until it snaps. What is actually going on is called stress hardening. Every time you stress/bend the wire it gets harder/stiffer at the molecular level until it loses all toughness and becomes brittle enough to break.

And, dear Mini, you want to make brittle a piece of my car that is already weak?

Really.

That’s INSANE. The metal would lose the toughness that allows it to absorb impact. It would be more likely to crack if it bends again, which is likely because the root cause of the problem is not addressed. It’s like repairing a ceiling after water has dripped through it from a leaky pipe without fixing the leaky pipe.

Mini has provided a repair, but no fix. They also refuse to cover this repair under warranty, stating that the problem is caused by “accident damage.” If the car was sold only for competition, I would understand this kind of damage resulting from normal street driving, but this is not a competition-only vehicle: it is a street car, designed to be driven over real-world conditions like cobblestones and potholes. You cannot design a car that cannot hit the occasional pothole without damage, but that’s what Mini has done.

The weak strut tower crown is a design flaw. If it was designed correctly the car would not fail at this point as so many have. A design flaw is not the consumers’ fault; it is the fault of the manufacturer. Why should the consumers have to pay for it? Why isn’t there a Mini-approved fix for it, instead of just a ridiculous repair?

Thank the entire pantheon of automotive gods that there is a fix for this problem and I found it available at most shops other than Mini dealer service. I will have to discuss all my options with Eric and see what will work best with my needs, but the cause of the failure will be fixed and failure will not occur again.

Shame on you Mini and your parent company BMW! You have documented the problem to your own service departments. It’s all over the web as a major weakness of your otherwise wonderful little car. You have been good enough to replace what needed to be replaced, you have been good enough to inform me of recalls and care for them promptly, your dealer and its service department are generally quite wonderful (minus Steve, never-returned calls, long lead time, and location), and the car itself is a joy.

This problem is unacceptable. You must take responsibility for it and install the necessary components that prevent the problem from occurring. You must correctly fix all cars that have been damaged as a result of this flaw.

As it currently stands, I am loathe to either buy or recommend another Mini.