2002 Alero

Hello All. I will begin by saying I do not know the proper terminology when it comes to cars, so I will apologize in advance. So, I have a 2002 Alero with 124,000 miles and it’s been giving me problems lately. Sometimes while I’m driving my car just shuts off. Radio still on and lights work, but the car just stops running. There are days where I can start my car with no problems and there are days where my vehicle doesn’t start at all for days/weeks. I’ve taken my car to two different shops and they didn’t find anything wrong with it but as soon as I got it back it started doing the same thing again. Any suggestions as to what is wrong with this car or what I need to do?

No need to apologize. You’ve done nothing to apologize for.

Did either of the shops do anything at all to the car? Did they check for stored malfunction codes? What exactly did they write on the shop orders?

Are there or have there been any other operating symptoms that have been slowly developing? Things like failing spark plugs or a dying pump will often begin to display symptoms for a time before they become too bad to keep the engine running.

Have you had the battery and charging system checked? It takes very little power to operate a radio and lights, far less than it takes to keep the sparkplugs firing.

Were the battery cables checked? Cleaned?

“the car just stops running”

“I’ve taken my car to two different shops and they didn’t find anything wrong with it”

That’s because the shops have probably hooked up their scanner and retrieved no fault codes at all, and they don’t know how to proceed, because they can’t think outside of the box

Sounds like the crankshaft position sensor may be failing

A very high percentage of bad crankshaft position sensors do NOT generate any kind of fault code

Run into this MANY times

@the same mountainbike the first shop I took it to hooked it up to the machine and said no codes were coming back and after that they just did a new vehicle inspection because I had just bought it from a private owner in February. The only thing they said was that they see where I’m going to need some motor mounts. The dealership I took it to said they were waiting for the car to cut off of them like I said it cut off on me and it never cut off for the 5 days that they had it so they didn’t do anything either

I would have to Concur with @db4690 …these sorts of things tend to stump shops that want a quick and easy diagnosis. Those crank or cam sensors go out to lunch sporadically and could drive the uninitiated nuts trying to figure it out.

Not a bad place to start honestly…Crank or Cam sensor. Sometimes they do tend to fail and no code is present…Ive seen it meself…WHY? I dunno… I dont focus on the why’s too much anymore…I just get things moving again.

In addition to the sensors… IF and when it stops running again…it would be a great time to look into the fuel pump to see if it is still running… When you get to know these things you can tell between a fuel pump failure and a cranks sensor failure. The crank or cam sensor issue is like someone flipped a switch and things just shut down… Fuel tends to be a more gradual shut down process…not as immediate. If that makes any sense to you…

Blackbird

I concur with db’s possibilities, but I’d personally start by checking the battery and charging system including the connections.

Your car is likely on the recall list for a defective ignition switch. If you have any weight on your car key ring, REMOVE IT!. Then go see a GM dealer and see if your car is included.

One of my wife’s friends has a car similar to yours and it badly needed a new switch since it periodically stopped the car!

All good ideas above. When it doesn’t start, does it still crank … that rr rr r rr sound, but doesn’t catch and run? Or doesn’t it even crank? If the former, that could be consistent with a bad crank sensor. If I had this problem and it cranked but didn’t start, the first thing I’d do is test for spark while the problem was still occurring. That info would narrow down the possibilities considerably. Do you know how to do that test?

Excellent possibility, Doc. It never occurred to me.
When it acts up, you might also want to try jiggling the ignition key. You just might get lucky and confirm a bad ignition switch.

@GeorgeSanJose the car doesn’t make a sound when Itry to start it

If the engine doesn’t even crank over, may want to look at that ignition switch

It sort of does sound like there’s an ignition switch problem involved. One idea to test that idea, just drive the car with one key, nothing else on the key ring. See if that helps. Sometimes the weight of all the other dangling keys can foul the ignition switch.

The no-crank problem may or may not be related. There’s about a half-dozen reasons why you’d get that no-crank condition. The quickest way to the solution: Make sure the battery connections are clean and tight. Next, ask your shop to measure the voltage at both starter motor electrical terminals, terminal to starter case, during attempted cranking. If both are above 10.5 volts, replace the starter. If either is below 10.5 volts, work backwards from the starter towards the battery to find out why.