Skip the auto shop - Our mechanics make house calls

Q: My car keeps shutting off for no reason

asked by on

I'm curious? My uncle put in my alternator because I needed a new one and ever since then my car keeps shutting off out of no where? What could that be? I just got it out of the shop for all the recalls to be fixed and I had the oil changed.
My car has an automatic transmission.

Hello. There are a number of reasons why your car will act like this. The most common cause of this is either a failing crankshaft position sensor, a fuel pump issue, or a failing ignition control module. This should not have anything to do with the alternator replacement unless the battery is not charging and it is draining. I usually install a scan tool and check the sensor readings first. I check to make sure that the crank sensor is reading correctly. If it is then I check the fuel pressure to see if it is falling off. If it is then the fuel pump or pump circuit may be bad. If that is fine then the ignition module needs to be removed and tested as that is the most likely issue. If you want to have this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose this.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My car keeps shutting off for no reason

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Wont start 2003 Pontiac Grand AM

Hi there. A fairly common clanking noise for GM vehicles and no start condition could be the result of a separated harmonic balancer/vibration damper. More than likely the CKP (crankshaft position sensor) has been damaged by the separation as well....

Q: 1999 Pontiac Grand AM runs rough and smells weird

Hello. An engine running rough at idle could be a vacuum leak creating the wrong fuel ratio for the engine to operate correctly. The smell is probably unburned fuel caused by the vacuum leak issue. The belt shredding could be...

Q: Random hiccups and fuel problems, what could it be?

The fuel pump relay is most likely staying engaged even though you have turned it off. A malfunctioning fuel pump relay can also lead to the pump not turning on at all or it shutting off intermittently and without warning....

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...