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Pete, Pontiac Technician
Category: Pontiac
Satisfied Customers: 29083
Experience:  17 Years Pontiac Technician and training.
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Pontiac G8: My 2009 Pontiac G8 GXP is dying at random time

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My 2009 Pontiac G8 GXP is dying at random time while driving. No warning, no spitting or sputtering. It is as if someone just turned the switch off. It happens when slowing down or coasting. I have had the fuel system cleaned at a dealership but it is still dying. Please help. 6.2L LS3 V8 if that helps.

Hi my name is XXXXX XXXXX I will be glad to try and assist you with this.I may need more info in some cases to help with answering your question.

Has there been any point in time that it may not restart right away to where it has to sit before it restarts?

Let me know,thanks Pete.

Customer: replied 4 years ago.

No. It has died a total of 15-16 times over the past two weeks and it has restarted immediately each time. Engine has run strong entire time as well.

One common component to fail and cause this here is the crank position sensor.This sensor is located behind the starter.The starter has to be removed in order to access and replace this sensor.

This sensor can heat up with the engine temperature and when it weakens it can lose its signal,when it loses its signal it can cause this stall out here.In some cases the vehicle may start right back up and in others the vehicle may have to sit a period of time before it will restart.This usually wont cause a fault code to set making it difficult to diagnose and most likely this is why the dealer didn't see this as a fault.The only way to test to see if this is failing is when the vehicle is acting up and not starting,in this case the vehicle starts right up making it difficult to diagnose.

From what you have described here this sounds like the component at fault needing replaced.This sensor can cost around $50 and 1.2 hours labor to have replaced.


Thanks Pete

is my profile if you need anything in the future on your vehicle here,you can save it to your favorites and come back if you have any future questions on your vehicle (besides this question here).
Customer: replied 4 years ago.

Are there any other possible culprits that could cause this symptom without throwing a code? I ask because a couple of times this happened before the engine really got up to temp completely. Maybe 3-4 minutes after I started it up. Could an Ignition switch or ignition sensor do this? Mass Air Flow sensor? Just want to make sure I cover all bases in case the crank sensor does not fix it. Thanks!

The electronic ignition switch is another common component that can cause the vehicle to shut down like this here as well.The crank sensor is most common and in some cases doesn't require warm or extreme engine temperatures to cause it to stall out,it may occur on a cold start or shortly after starting the engine.

The ignition switch can be the culprit as well but on a newer vehicle you may see ignition fault codes set if this switch itself is starting to fail.The mass air flow would usually set a code as well.

Thanks Pete
Pete and 6 other Pontiac Specialists are ready to help you

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete