What caused my engine to shut off?

November 24, 2008 10:07 AM

What caused my engine to shut off?

I was driving at about 65 mph and was resetting the cruise control on my 2006 Pontiac Torrent. The last thing I did before losing the engine was hit the "minus" button two times in a row by mistake (the button that would normally reduce your speed a bit while still keeping the cruise engaged).

The speedometer and tachometer needles immediately dropped to zeo and the engine lost all power. I made it over to the breakdown lane and stood on the brakes to stop. I lost no electronics though- all lights, the radio, etc. all remained functioning through the whole thing.

I turned on my flashers and freaked out for a few minutes. Then I restarted the car, got back into the flow of traffic and nothing else happened the whole trip. (I did not attempt to re-create the incident, however.)

I found info on "kill switches" online but I don't think this that... Would it be possible that some sort of combination of button/control pressing would purposely cause the engine to shut down? If so, why? Or was it maybe just a short circuit?

posted by I_Love_Bananas to travel & transportation (10 comments total)

It's not a deliberate feature. :)

I don't know about your car specifically, but cruise control systems all have some measure of control over the throttle in the engine. I assume this car has an electronic throttle control, in which case a buggy cruise control could definitely do this.

See if you can make it happen again, and if so, get it to a dealer for service. If you can't replicate it, they'll probably tell you there's no problem...
posted by paanta at 10:24 AM on November 24, 2008

Would it be possible that some sort of combination of button/control pressing would purposely cause the engine to shut down?

No. Absolutely not.

The cause could be a variety of things, from electrical connections to fuel feed issues. The fact that the speedometer, as well as the rev counter/tacho went to zero suggests a power feed issue to the engine management electrics in some way.

You need to get this looked at with some urgency, as the next time it happens, you may be less fortunate with when and where it occurs. Make sure you have all the details you can remember with you when you discuss it with the mechanic/dealer representative.
posted by Brockles at 10:25 AM on November 24, 2008

Do check to see if you can reproduce it, however, somewhere safe. Telling the dealer that your car stalled out isn't going to get you anywhere, unless it logged the issue. They can do a much better job of diagnosing things if you can show them the problem.
posted by disillusioned at 10:36 AM on November 24, 2008

Similar, but worse, problem (the first complaint in the log).

So, as Brockles says, get it looked at immediately.
posted by Derive the Hamiltonian of... at 10:36 AM on November 24, 2008

Mr. F's PT Cruiser did this coming off the freeway once, except it was a near-total shutdown-- engine died, tach and speedo went to zero, electronics were wildly erratic. (Rather like every UFO-abduction-from-vehicle scenario you've ever seen on TV, actually.. just in the middle of the afternoon in Hollywood.)

Our mechanic diagnosed a defective battery, replaced it, and it hasn't happened since. I'd try to reproduce the problem, and then take it back to your dealer and, if possible, reproduce it for them-- if not, make sure they check the battery, the alternator, everything in the power system.
posted by fairytale of los angeles at 10:49 AM on November 24, 2008

If the engine doesn't sputter before it shuts down, it's not fuel related. It's an electric prob, and narrowing down requires a diagnostic. Probably the Throttle position Sensor. But like everybody says, take it in quickly (in light traffic!).
posted by artdrectr at 10:50 AM on November 24, 2008

My 2000 Nissan Sentra shut off at about 50 mph in mid-commute earlier this year. Turns out that model tends to have a defective mass airflow sensor. Nissan had not issued a recall; I had to pay through the nose to replace it.

Maybe ask your mechanic to query his database for engine shutoffs in 2006 Torrents; that's how we we diagnosed my problem.
posted by futility closet at 11:32 AM on November 24, 2008

If you press up-up-down-on-off and tap your break 3 times your car will be "activated" and become supercharged. No, seriously, did you hit a large bump? Have you checked fuses and wiring?
posted by Pollomacho at 1:28 PM on November 24, 2008

This is sometimes a symptom of a bad battery. It's worth a look. Certainly not anything to do with the buttons you were pressing. That's just coincidence.
posted by luckypozzo at 4:09 PM on November 24, 2008

From the page linked in a previous comment,

The contact depressed the brake pedal, but the vehicle did not stop.

This is typically a sign of someone relatively unfamiliar with a vehicle, or distracted, who pushes the gas instead of the brake. Once pushed, it feels like the car is accelerating on its own -- and when the person pushes the "brake" harder to stop, they're actually pressing the gas and so the car keeps going until they hit something or shut off the car.

The smoking gun tends to fall into two categories: first, modern cars have brakes sufficient to stop the vehicle even if the gas pedal is held to the floor simultaneously, so the scenario would require the gas to stick AND the brakes to fail simultaneously, *and* have those conditions both clear up right after the accident. Second, during investigation of the famous Audi 5000 unintended acceleration incidents, the results showed people were startled by a surge from the engine related to cold-start idle, and then flooring the gas thinking it was the brake, and this is a pattern that's been seen in other incidents.

This isn't to say you don't have a problem -- however, I don't want you thinking you have the same kind of problem being described in that bulletin.

What I'd advise is this:

#1: during a light traffic moment, with no traffic around, engage the cruise control.

#2: double-tap the minus button. See if the car shuts off.

#3: if it does, you have a winner; take it to the dealer. If it doesn't, it was either coincidence or flaky electronics; either way, you should take it in, but it'll be hard to diagnose if you can't replicate it.

A friend had a Renault Alliance that died randomly, and never got fixed; my wife's Mazda MPV did this once at a light, and never again. I had this happen to me in stop-and-go traffic on a freeway, and only realized after I got it pushed to the side of the road that I'd bumped the key off with my knee. So it might be a terrible problem, and it might be nothing -- start by trying to replicate it.
posted by davejay at 4:54 PM on November 24, 2008