WhiskeyTangoFoxtrot?? (Car intermittently dies while idling)

[DesertPuma]

I realize it's been awhile since I have posted, mainly because I really have not much more to say about Saturn's future (personaly I think they're toast, then again in my mind Saturn ceased to exist the moment SH was "re-assigned" by GM, anyway enough about that.)

My problem (and this is extremely puzzling), which just started happening toward the end of December.

While sitting idle (after stopping at a red light or slowing to a stop at the local Jack-in-the-Box) the car will, without warning, just suddenly decide to shut itself off, just as if I reached down and turned the key myself. Now the car does restart but not until about 3-5 minutes, within that time frame when attempting to restart, it cranks away but to no avail.

As mentioned the first time was end of December (I had just pulled into my driveway), it didn't happen again about a month later (Jack-in-the-Box), then not again until about 2 weeks later (Left hand turn lane on a very busy road), and as time has gone by it has been more frequent, twice in one day (about 2 weeks ago), and it hasn't happened since then. It's to the point now where we are no longer driving it except for short trips to the Grocery store or whereever.

I have an appointment to take it in next week, I suspect it might be the Passlock system getting fooled somehow.

Other than the normal Oil, Battery, and other dash lights that light up when you turn the key in the ON position without the engine running there are no indications.

Does anyone have any other ideas? Anything I can suggest to the Tech to look out for? (Sensor? Air Bubble in Fuel Line? Keys wearing down?) I am hoping the computer is throwing out codes, otherwise an intermittent issue like this will probably be hard to find.

Anyone else experience this?

03 VUE V6 3.0L, the car still runs like a top, and we still love it (especially now that it's paid off), but this is frustrating. Oil leaks I can deal with (just keep filling it with new oil), but I sure would hate for the car to die while in the middle of a left turn in rush hour traffic, or for that matter in a freeway traffic jam. This could be a very dangerous situation.

[Ritz]

I've seen a number of people here that know the 3.0L say that this is a symptom of the crankshaft sensor failing. Personally, I've never seen one that works sometimes and not other times, but perhaps this part is special. Perhaps you'll get other feedback as well, but you might want to check that first. They're cheap and not that big of a deal to change.

Cheers,

[fdryer]

^ ^ He's got that right ^ ^ - the crank position sensor (CPS) next to the oil filter. Intermittent is the worst type of failure as it happens more often than complete failures, in the S-series. Its not exclusive to them as it does occur to almost all Saturns except for the new ones - Ions, Outlooks, and Auras. Its a relatively easy DIY replacement if you want to try it as its quite involved to troubleshoot in our 3.0L V6 engines with hidden spark plugs and coil-over-plug ignition systems. If you read of typical troubleshooting in the S-series forums, you'll understand the ease of spark testing with conventional coils and plug wires to observe as opposed to hidden ignition systems making a spark test difficult. Saturn will have a hard time trying to find this as it can only be 'found' when the engine dies before them in the service bay otherwise you should expect the "we can't duplicate the problem" response unless they are on top of things while using their reader/scanner running diagnostics. It isn't the easiest to find here either, as the collective sharing of information from every Saturnfans member allows greater diagnostics numbers crunching to come to a very favorable conclusion with consistent results minimizing 'throwing parts at the car' repairs.

[BobbyP]

I third or fourth that... My sister's Eldorado had the same intermittent problem. It was the Crank Position Sensor.

[DesertPuma]

Thanks for the input. It certainly appears to be unanimous (at this point anyway). CPS it is. :)

Certainly when I take him in (I do have an oil leak that I alluded to in the OP) next week I will print out this thread and show it to them.

I do need to take care of the oil leak, but I wasn't about to pump (I'm guessing here) 500-750 into him and still carry this problem around.

Thanks again.

PS

How bout them Cardinals eh? They were quite literally one inch (maybe 2) away from taking it all. It certainly was an exciting year for us long suffering die-hard AZ Cardinals fans. (For me ever since they landed here in AZ in 1988, they were then known as the Phx Cardinals.)

[chillin05VUE]

Have you checked your Idle Air Control (IAC) unit? What happens is that when you lift your foot off the gas, the throttle closes and the IAC takes over. It lets air into the intake to keep the car running. It can fail internittenly causing your problem. I had the same thing happen on my '96 Cutlass. Every few months, while making a left turn, the car would die without warning. Lately, it would also stubble and if I didn't put it "N" and give it gas, it would die out while sitting in traffic. I was told that it was my IAC and the part alone was $150 (my cost since I work at a dealer) plus labor. Needless to say, I don't have the car anymore which is another story in its self. But have it checked out, you just need to have your intake system cleaned which would also clean the IAC. Or you might just have to pony up for a new IAC.

[pbw]

I'll guess Cam Sensor.

From Tech manual.
The Camshaft Position (CMP) sensor is located to the left of the cylinder 2, 4, 6 timing belt cover/exhaust camshaft sprocket. The CMP sensor is a hall effect switching device used to determine the position of the bank 2 exhaust camshaft. The CMP sensor detects a single tooth on the reluctor wheel of the camshaft, which denotes 900 before top dead center cylinder # 1 compression stroke. The sensor is used by the ECM to determine when cylinder # 1 is approaching top dead center necessary to synchronize the correct firing order. The CMP sensor is also used to enable sequential or independent fuel injection and to enable spark knock control.

As the reluctor wheel tooth rotates past the sensor, the sensors internal hall effect device pulls the signal circuit to ground. Therefore, the ECM expects to one see one high (12 volts ) to low (0 volts ) voltage transition once every two crankshaft rotations as the reluctor tooth passes the sensor. The signal circuit should be at 12 volts at all times except when the transition occurs. If an error occurs in the CMP sensor circuit during the drive cycle, the ECM will continue to supply fuel and spark to the correct cylinder at the correct time until the ignition is turned Off. If an error occurs in the CMP sensor circuit upon key-up, then the engine is started, the ECM will default to supplying spark to BOTH mating cylinders and enter non-sequential fuel injection. The engine may experience a 2-3 second extended crank, however, the engine will start and run.


Crank Sensor does...

The Crankshaft Position Sensor (CKP) is located underneath and slightly to the left of the oil filter housing. The CKP sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft reluctor wheel. The crankshaft reluctor wheel contains 58 teeth that are 6 degrees apart with a 12 degree span that is uncut. This 12 degree span is used to locate the cylinder # 1 top dead center piston position used for engine synchronization. The CKP sensor in conjunction with the camshaft position (CMP) sensor can properly synchronize spark timing; fuel timing and spark knock control.

The large numbers of teeth on the reluctor wheel are used to correctly detect engine misfires. The ECM automatically learns the variation between all of the 58 teeth under 24 different engine speed/load ranges. To correctly detect misfires, the ECM will monitor the time it takes to pass 20 of the teeth (120 degrees of crankshaft rotation) after a cylinder has fired. If the time (based on engine speed and load) to pass the 20 teeth is too long, a cylinder misfire has occurred.


Either way you can replace either one of them really easy!