Shuts off while driving at highway speeds?

INDIKA69

MEMBER
2000 PONTIAC GRAND AM
3.4L
6 CYL
2WD
AUTOMATIC
178,500 MILES

Shuts off while driving 65 MPH as if the key was turned off. Didn't give any indication of fuel loss like spitter or sputtering it just shuts off. It cranks just fine but won't start, but wait a few minutes 10 or so and it started like normal. Drove for another 20 miles and again just shut off just like before. This time it took a little longer waiting but it started just fine. Third time it just shut off It did act as if running out of gas for just a second. Long enough to look at the tach and see RPMs drop a little then shut off. I waited about 10 minutes, and it started again. Fourth time it shut off just as if key were turned off. But it started right back up with no waiting. Got it home and have not tried to drive it but have turned key on to listen if fuel pump was coming on and it does so my thoughts of that being the problem are not my first choice. Any ideas on what the problem could be?

Friday, January 10th, 2025 AT 8:20 AM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
49,970 POSTS

Yes, it sounds like the crankshaft sensor needs to be replaced, but can I ask if you have any codes? Also, a fuel pump locking up will cause the engine to stall like you turns the key off which the GM products of this year range had. When it will not start try to use starting fluid which can help us see if the problem is fuel related. I have also seen the MAR stop reading which tells the PCM to shut the engine off. There is also an engine oil switch that can shut the engine off as well, so make sure the engine oil is full, or the switch can go bad as well. I would go over this video to see if it can help us. As you might know there are about 10 items that can cause this.

https://youtu.be/lXLJbuAZ4CE?si=h1ySI5qDwV3M44ug

and

https://www.2carpros.com/articles/engine-stalls

Here is the location for the crankshaft sensor and MAF sensor. Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.

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