While driving my car will randomly turn off. I have gotten a new battery and alternator but is still turning off.
I was driving on the freeway when my temperature gauge dropped to 0 then went back to normal, and dropped again. My car then would lose engine power for a second then jerk forward like the power was regained, while sitting at the red light of the off-ramp car was acting fine, once the light turned green and gave it some gas it died. I turned the car off, waited a second and it started right up and drove home, no issues on the rest of the drive. Lights never dimmed, so. I know it is not an electrical issue. What could this be? coolant thermostat going bad, crankshaft position sensor, camshaft position sensor, or fuel pump sensor in the tank? Any help would be appreciated greatly.

 

Is the temp gauge turning off? If so it could be a wiring problem causing electrical power issues with the ign and or fuel pump, etc.

Is the ign switch OK?

Check wiring for damage. Perhaps a rodent did damage.

Check battery cables and the connections, the main fusible links for damage and corrosion.

 

It could be, but why would the gauge fluctuate, then once I started it at the light be acting normal?
I have never had any issues with the IGN switch.
I had a mechanic do a OBD2 scan and only thing that came up was a bad thermostat. Would this cause the entire car to shut off though?
He also did a volt check through the wires that went from the alternator to the battery and groulds and all of those tested out good.
I never lost electrical power, so I dont think it would be the battery.

 

Wiring issues can be very challenging to figure out.

Any other dash gauges or anything else stop working at the same time as the temp gauge?

Do you have any trouble codes from the OBD scan.

How did the mechanic determine the T-stat was bad?

 

No, it was just the temperature gauge that fluctuated.
The only code that did show up was the P0128, which is the coolant temperature not getting to temperature quick enough.

 

Your checking finds no wiring issues then?

Might be a failing fuel pump.

 

Correct, the checking yielded no wiring issues.
I just replaced the crankshaft position sensor. if it does it again, then we think it is the fuel pump.
Wanting to do the cheap fixes first.
Anything else it could be?

 

If your mechanic has an OBD reader with real time output they can check the various sensors as the engine is running. The reader can also display coolant temp.

Any relation to the stalling and how much gas in the fuel tank?