2002 Saturn loss of power

I have a 2002 Saturn SL with 171000 miles on it. Monday, on the highway, going about 65 mph, the car suddenly loses all acceleration power. I pull to the side of the road, the check engine, low oil, and low battery lights come on. Took it to the shop, replaced the battery and alternator. Pick the car up Tuesday. Wednesday morning, same thing happens on the highway. Shop says they can’t duplicate the problem for 3 days, but have done research and relearned the crank position sensor. Friday, 15 minutes after picking the car up, it again does the same thing, in almost the exact same spot. Having very little knowledge of cars, what can I tell the shop to look for, and how do I know I’m not being taken advantage of?

Is the car still running when this happens? Or are you saying that it completely stalls? If it stalls all of those lights are supposed to come on.

Was/Were there code/s that were pulled from the computer? They come in the format Pxxxx where x’s are numbers. Hopefully the shop wrote it on the invoice or can tell you. If not many auto parts chain stores will read these codes for free.

“relearned the crank position sensor” also makes no sense. So get clarity on whatever that means. However, if there was a code that had something to do with the crankshaft position (CKP) sensor AND the car is completely stalling then there is a good chance that you have a wiring fault in the CKP sensor wiring - something like a loose connection. The CKP sends a signal to the car’s computer to tell it where the engine is in its rotation cycle. This lets the computer control the fuel & spark for the cylinders. If that signal is lost the computer can’t feed fuel and spark - nothing explodes and the engine doesn’t run.

Anyway, as you can see you need to try to give lots more info. You have mechanics who have looked at it for several days. None of us can actually do that.

The car is still running when this happens, and there is still power as the lights stay on, radio stays on, etc. There are no codes pulled from the computer; this is part of the problem the shop has been telling me. There is no memory in the computer of any type of issue, no codes show up, and thus there is nothing for them to go on. As far as the crank position sensor is concerned, I was told that the mechanic had done some research and found out that a similar issue has happened in other cars and was resolved when the crank position sensor was reset or “relearned.” He said this was a simple procedure that didn’t involve any parts and that he could do with his scantool.

I know that I’m probably not giving the best information possible, but I am repeating all information that my shop has given me. The copy of the invoice says the following: “rd tested several times ck wth scan tool for codes traced wiring and ck all on line data related to a possible concern found info about crank sensor relearn performed relearn mode with scan tool retested”

You say the car is still running when this happens AND that the check engine light is on. The car is running + check engine light = diagnostic trouble codes stored in the computer. So something there doesn’t add up.

When the car loses all accel and you turn to the side of the road with these dash warning lights on what happens next? What does it look/smell/sound/feel like as it sits there running, stopped on the side of the road with warning lights and no ability to accelerate? I’m actually thinking that what you describe makes a lot more sense if the car is actually stalling. How do you know that it is actually still running at this point?

Then, what do you do next? Do you immediately turn it off and call a tow truck each time? Or do you turn off the car for while, restart and drive away? If it restarts and drives, describe it - any sights/sounds/smells/feels.

Has your mechanic check for blockages in the exhaust system? Has your mechanic checked your fuel pressure under load? How old is your fuel filter? Has your mechanic tested/checked your ignition system for “heat soak”?

To answer one of the other questions - if this shop was going to take advantage of you it is pretty easy to do with intermittent problems such as this. They could have replaced the CKP and charged you a lot. Then if it doesn’t actually fix it its not their problem. They could be trying to sell you fuel injector flushing services and intake cleaning etc. etc. Use of a scantool to test and reflash a part without replacement - sounds reasonable to me.

When I pull over to the side of the road after this happens, nothing smells or sounds different. If I try to accelerate, nothing happens and it doesn’t feel like anything happens at all. If I restart the car, one of two things happens. Either (1) the car idles very rough, and turns over, only to have all power die out immediately, or (2) I restart the car, it restarts fine, and I can drive a few hundred feet before the problem happens again. The car seems almost as if I am driving in a new gear. I have tried waiting a while in between when I pull over and when I restart the car and it idoesn’t seem to matter.

As far as I know, nothing has been checked in the exhaust system or ignition system. I do not think that anything has been checked with fuel pressure, although the mechanic has told me that everything is fine there. He seems hesitant to check anything that’s not electrical as no codes have, as yet, shown up.

My 2000 Saturn sl did pretty much the same thing. On the freeway, without warning, my car just lost all power. I pulled over, waited for a few minutes then started it again but it made a really bad knocking sound in the engine. Turned out off, waited 5 more minutes and it started right up but now the check engine light is on.

Get the diagnostic codes read and post them here @Dea_Malone . If it weren’t for the knocking sound you heard, I’d guess this was something simple. But with that knocking sound, well, like I say, best to start with the diagnostic codes.