DEAR CAR TALK: How vulnerable to theft are push-button start cars? I've heard thieves can copy the signal of the key fob.
Realistic possibility or "Mission Impossible" fantasy? — John
DEAR READER: A little of both, John.
First, you have to understand that car theft is a cat and mouse game that will probably never end.
Every time thieves (whose full-time jobs, remember, are being thieves) get around the latest anti-theft technology, car manufacturers — encouraged by insurers who actually pay the stolen car bills — add new technology to foil the thieves.
Rinse, lather, repeat.
Overall, car thefts have dropped dramatically over the last 30 years — they're about a third of what they were in 1990 — although they've inched up a bit in the last few years.
Most of this drop is attributable to immobilizers. Most car makers put a computer chip on the key. And unless the car's computer recognizes that specific computer chip, it won't allow the car to run. That put the hot-wiring crowd right out of business.
Push-button ignition works by storing a code in both your key fob and the car system's computer. Unless the car is able to read that code from a paired key fob, it will be immobilized. And the key fob has to be within a few feet of the push button-usually inside the car.
Now, some enterprising thieves have bought devices that can read (aka steal) and amplify a key fob's signal. One device steals the signal, presumably from outside your front door, a few feet from where your key fob hangs on a hook. It then transmits that signal to a second device held by another thief standing next to the car. And that second device transmits the code to the car. This is explained in detail on a number of websites — that, just by coincidence, sell steering wheel locks.
Anyway, car makers are already striking back, with some using a wider band of frequencies in key fobs than the thieves' devices can detect. Other manufacturers set their key fobs to go into a "sleep mode" when they're not being used, so no signal comes out of them when they're not in use.
And the truth is, some manufacturers try harder to prevent theft and implement new, anti-theft technologies faster than others. You may have read about the recent rash of Kia and Hyundai thefts, where teenage thieves discovered how easy it is to steal one of those cars with a screwdriver, due to a lack of immobilizer. Hyundai and Kia say they're adding immobilizers to future models — but suggest current owners buy a steering wheel lock and a 140-pound rottweiler.
Anyway, it's always possible for a thief to steal a car. But it's certainly a lot harder than it was years ago. And the cat and mouse game will continue.
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DEAR CAR TALK: I have a 2010 Honda Pilot. Last week, the bolt that goes through the pulley holding the tensioner assembly sheared, and the belt did not break.
I was able to remove the remaining bolt and installed a new assembly. Three days later, the bolt sheared again and the belt did not break. What would cause this? Thanks. — Wesley
DEAR READER: You did, Wesley. I'm guessing you overtightened the bolt.
It's pretty common for this bolt to break on this vehicle. I don't know why — a rare case of under-designing a part by Honda. So, the fact that it broke after 12 years is not unusual or alarming.
But my guess is that when you replaced it, you tightened the bejeebers out of it. The tighter, the better, right? Except this bolt calls for a torque of only 40 foot-pounds or so. That's not a lot. And if you tighten it with your socket wrench, it's very easy to go a lot tighter than that.
And what happens when you overtighten a bolt? It stretches, making the metal more brittle, and prone to breaking. We see this with wheel bolts, where it can be very dangerous. It's easy to assume that when you're attaching a wheel, the tighter the better. But if the wheel bolts get over-tightened and stretched, they can snap off while you're driving.
And if you think it was exciting having your tensioner assembly bolt shear off, try five wheel bolts on a curve at 50 mph.
Anyway, I'd try one more time. And this time, use a torque wrench. Or have a mechanic do it for you if that's not in your toolbox or your skill set.
I think you'll have better luck. And if not, don't write back, Wesley, because that's my best guess.
Ray Magliozzi dispenses advice about cars in Car Talk every Saturday. Email him by visiting cartalk.com