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2000 Pontiac Grand Prix Shuts off without warning while driving.

G

geeksweep

New member
Hi all! I have actually read these forums before when having other Pontiac issues so now I am finally joining and hopefully someone will be able to tell me what my problem is.

Car Stats:
Year: 2000
Model: Grand Prix GT, 3800
Miles: 226,886

While driving home from work this evening i was at a stop sign, started to turn right and the car just died on me. No sputter, no whimper. just stopped. The oil light, temp light, battery light came on as you might expect as this happens also when turning the ignition but not starting the car itself. Tried to start it up multiple times. The air would come on and it would try to crank but wouldn't so no luck there. A nice girl came by and offered to help me jump the car and not really knowing what else to do I got out my car cables, hooked it all up and waited. After about 1 minute, the car didn't start back up. I waited another 30 seconds. Tried again and it started back up. I thought at that time that the battery might be going dead but as an afterthought never heard of a battery going bad shutting down a car while running before. In any event, I thought I would try to go to Autozone to check to see the condition of the battery. The metal pieces(nuts) themselves don't look too corroded on the outside.

About 1 mile or less as I get onto a busier highway I am at a light, make the left, straighten out and the car dies again. Just dies. no sputter, no whimper. nothing. Now I'm screwed because its 5 PM and who in the world is going to stop for me again in all this traffic? After about 30 seconds I was able to start it up again after the 3rd try. In the meantime my wife called her dad and he said he has had a car stop like that before when turning when the oil was low. So i decided to go to the nearest gas station to check the oil. The oil was low enough to where it says "Add 1 Quart" and I did so and drove home (another mile or so) without it dying.

At this point I dont know what to think but here are my thoughts.

It cant be the battery going dead, or I would not have gotten it to start the 2nd time without hooking up to another car.
Maybe using the car cables and it starting back up the 1st time was a sheer coincidence and doesnt have anything to do with the battery.
If the alternator had drained the batter between the 1st and 2nd incident I wouldnt have gotten it to start up again unassisted - so I do not think that this is the problem.
If the oil was so low that when turning the car doesnt detect much oil and shuts down, then the "Check Oil" light would have been lit and that never happened.
Every once in a while the "service engine soon" light comes on but that always comes back as the "catalytic converter" and while I have had plans to replace it I havent done so yet - but dont think this could be the problem. (i would think this would only stop you from getting the power you need to drive)

All the local non-chains here in town are not open tomorrow so I am kinda stuck at home until Monday morning but I thought I would come on here and check to see if anyone had any ideas before going into the shop on Monday.

As a final note, I would say about 2 or 3 months ago i was driving home from the store and as I was making a turn the car did the same thing. stopped dead cold. not stutter or whimper. Immediately on the first try to re-start it it cranked up successfully so I thought, "well that was really scary and weird" but it never happened again until just now.

Would like to see if anyone could point me to the right diagnosis if possible or at least ask more questions or comment to see if we can narrow down any possibilities. THANKS!

EDIT: The "Service Engine Soon" light was on this morning as well as the "trac off" light and the Service Engine Soon light was on again this afternoon as well immediately after starting the car but i cant recall 100% if the trac off light was on or off. Sorry i forgot to mention that in my post. thanks.
 
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didnt read the whole post, but the first 3 lines leads to a crank sensor gone bad. its one of the only sensors that go bad with out setting the cel light on.
 
Could possibly be the Crank Position Sensor. It will shut the car down without warning. Sometimes it shows a Check engine light, some times it doesn't.

Happened to me twice. Just out of the blue, bam, engines off. Took multiple tries to restart. (PCM need the crank sensor input for timing)
 
Also, welcome to the forum geek. That's probably the most complete diagnostic post anyone has ever made, let alone their first post. Props to you good sir.
 


If the crank sensor fails, the computer has no idea where the engine is in it's rotation, so it cannot make the proper calculations for ignition and fuel timing for each cylinder.
 
machinegunsquid said:
Also, welcome to the forum geek. That's probably the most complete diagnostic post anyone has ever made, let alone their first post. Props to you good sir.
Click to expand...

thanks! I havent had to do too much to this car (last repair was rack & pinion gone bad) but i can say at almost 230,000 i still get about 27 or 28 MPH on the highway. It also has a HUD so its kinda grown on me :)
 


machinegunsquid said:
Could possibly be the Crank Position Sensor. It will shut the car down without warning. Sometimes it shows a Check engine light, some times it doesn't.

Happened to me twice. Just out of the blue, bam, engines off. Took multiple tries to restart. (PCM need the crank sensor input for timing)
Click to expand...

I see well like i said before, the "service engine soon" light been coming on and off for about 4 years now and every single time the code comes back that points to "catalytic converter" but i never got it fixed but had already planned to real soon. So anyway I didnt think too much about it...err. i forgot to mention i my post that the light did come on this morning and was on again this afternoon immediately after starting the car, ill edit my post.
 
The skinny on the crank sensor.

How it works.

The 3X 18X Crankshaft Position Sensor is two Crank Sensors in one assembly and is a Hall-Effect type Sensor that needs an external Power and Ground source to create its Crank (CKP) Signal. As such, it produces an On/Off DC Voltage Signal that can be measured with a Multimeter, an Oscilloscope, and even an LED Light.
Here, in a nutshell, is 3.8L/how the Crank Sensor works:

  1. When you turn the Key and Crank the Engine
    • The Crank Sensor gets power directly from the Ignition Control Module (ICM).
    • This power is in the form of 10 Volts DC.
  2. As the Crank Pulley starts to turn
    • The Vane assembly (attached to the Crank Pulley) starts to slice thru' the Crank Sensor.
    • One part of the Crank Sensor produces 3 ON/OFF signals for every one Crankshaft revolution.
    • The other part creates 18 ON/OFF signals per Crankshaft revolution.
    • This is the reason the Crank Sensor is called the 3X 18X Crank Sensor in some service literature.
  3. These Signals are fed directly to the Ignition Control Module. Once these Signals are received:
    • The Module starts Sparking the Ignition Coil Packs.
    • The Ignition Module also creates a Fuel Control Signal that it sends to the PCM (Powertrain Control Module=Fuel Injection Computer) to start injecting Fuel and a host of other things.
  4. If any of the above Signals goes missing, your 3.8L GM vehicle will Crank but Not Start.
The most important thing to know about the 3X 18X Crank Sensor is that if it goes BAD, your 3.8L V6 equipped GM car or mini-van will Crank but Not Start due to a lack of Spark and Fuel Injection.
 
Fivefingerdeathpunch said:
The skinny on the crank sensor.

How it works.

The 3X 18X Crankshaft Position Sensor is two Crank Sensors in one assembly and is a Hall-Effect type Sensor that needs an external Power and Ground source to create its Crank (CKP) Signal. As such, it produces an On/Off DC Voltage Signal that can be measured with a Multimeter, an Oscilloscope, and even an LED Light.
Here, in a nutshell, is 3.8L/how the Crank Sensor works:

  1. When you turn the Key and Crank the Engine
    • The Crank Sensor gets power directly from the Ignition Control Module (ICM).
    • This power is in the form of 10 Volts DC.
  2. As the Crank Pulley starts to turn
    • The Vane assembly (attached to the Crank Pulley) starts to slice thru' the Crank Sensor.
    • One part of the Crank Sensor produces 3 ON/OFF signals for every one Crankshaft revolution.
    • The other part creates 18 ON/OFF signals per Crankshaft revolution.
    • This is the reason the Crank Sensor is called the 3X 18X Crank Sensor in some service literature.
  3. These Signals are fed directly to the Ignition Control Module. Once these Signals are received:
    • The Module starts Sparking the Ignition Coil Packs.
    • The Ignition Module also creates a Fuel Control Signal that it sends to the PCM (Powertrain Control Module=Fuel Injection Computer) to start injecting Fuel and a host of other things.
  4. If any of the above Signals goes missing, your 3.8L GM vehicle will Crank but Not Start.
The most important thing to know about the 3X 18X Crank Sensor is that if it goes BAD, your 3.8L V6 equipped GM car or mini-van will Crank but Not Start due to a lack of Spark and Fuel Injection.
Click to expand...

thanks for the run down and education! I see the part itself is not pricey at all so what should I expect to pay to get this replaced if this is the problem?? (i wont go to the dealer but a well respected local body shop)
 
My car did the same exact thing for some time without throwing a code. It wasn't too bad initially. Once in a while, I'd go out to the car, and it just wouldn't start. I'd try for 5 or 10 minutes, and got nothing. I'd go back in my home, then come out and try again 20 or 30 minutes later, and it would fire up as if nothing happened. It had nothing to do with time of day, weather, hot or cold engine, etc. It was completely random. Then it started happening while driving, which can be quite dangerous. Almost got caught in the middle of a left turn once when it died. Luckily, I threw it into neutral, quickly tried to restart it, and it turned over on the first try so I was able to dump it back into drive and get out of the way. It was like a scene from a bad action movie!

I was pretty sure it was the crank position sensor, but not positive. Then I finally saw an obvious clue that sealed it for me. A couple of times, the car stuttered for a split second (almost like someone bumped you from behind), and the tach dropped to 0 RPM. However, the car was still running. If I shut the car off, and restarted it, the tach would operate like normal until the stutter happened again. After researching this a bit, I discovered that this was a sure tell tale sign of a CPS because the tach gets its signal from the CPS, so if there's any interruption in the signal, the tach drops to 0 (even though the car is still going) and won't reset again till you restart the car.

I know you didn't mention anything about the tach, but even so, my first suspicion with what you described would be crank position sensor. It's pretty common on these motors.
 


I would look at the actual book time, but I can't get on my Alldata site anymore.

A guess would be 1 to 1.3 hours of labor. I mean the only time consuming part is just using a harmonic balancer puller to get the HB off, then its just 2 bolts for the sensor.
 
Fivefingerdeathpunch said:
I would look at the actual book time, but I can't get on my Alldata site anymore.

A guess would be 1 to 1.3 hours of labor. I mean the only time consuming part is just using a harmonic balancer puller to get the HB off, then its just 2 bolts for the sensor.
Click to expand...

thanks again! whats weird, as i mentioned in my post is that this happened for the 1st time back 2 or 3 months ago, probably closer to 3 but it never happened again until now. Ive been able to start it up, drive it and everything with no problems. If the sensor was bad then then why is it doing this all of a sudden 3 months later?

Also how will the people at the shop know for that is the problem if it doesnt send out a code? How will the test it? Can they run a signal test?
 
Ask the sensor personally lol.

They are just straight up wierd like that. I've seen it many a times where it can happen 1 week, then not again for another 2 or 3, then just do it again for no reason.
 
once it gets bad enough the car wont re start, it may 3 hours later, or a week later.

we've all seen these little sensor cause all sorts of stall, misfire, and not start up any more at all. make sure the wires to the crank sensor are not damaged as well. some times they rub the belt and get cut.
 
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