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.

A: Hello. There are a number of reasons why yo...

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Big fan never comes on. If I run the AC, the smaller fan comes on.

Hello. The cooling fans for your vehicle are powered by the computer, through a relay. If they are not functioning properly then it may be possible that the relay or computer are the issue. I would check the relay and...

Q: Car hood won't open

Hello. Overtime hood springs will loose the ability to force the hood up when the hood latch is pulled. It's best to have an extra set of hands when trying to get it open so one may pull the hood latch...

Q: What makes my transmission so rough?

In order to tackle this question appropriately, more information would be needed to guide us in the right direction. One question is, does the transmission slowly engages when you first drive your vehicle, or after it has sat for a...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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 to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...