Rough idle, shuts off?

TARANOEL

MEMBER
2012 CHEVROLET MALIBU
2.4L
4 CYL
2WD
AUTOMATIC
195,000 MILES

Okay, I'm going to tell you exactly how this car acts. When I first get in to go anywhere it runs great. If I go straight and get on expressway, I will drive it anywhere. But when I am going under about 30 MPH, starting and stopping, sitting in idle it begins to miss, vibrate, almost like a knocking sound. I have had it hooked up to a computer and all it shows is an oil sensor code and o2 sensor. They said it was old codes. Anyway, over the past few years I have figured out that I can take my battery cables off and reset the computer and it will run okay for about a day. And if it shut off in the middle of the road, I can jump out and unplug my cam sensor lol this car is crazy. No one around here knows because nothing shows up on the test, please help me figure this out. I'm a single mom with a job. I travel 30 miles a day to work, and this is the only thing we have to get us places. Thanks in Advance!

2 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

When this happens and it stalls, does it start right back up? Also, do you have a live data scan tool?

If you do, with the engine at operating temperature and at idle, see what the short-term fuel trims are and let me know. If possible, I would love to know what they are when it starts running rough.

Next, a common symptom of a failing crankshaft position sensor can be stalling. Take a look at this link and let me know if it mirrors what you have experienced. Interestingly, a crankshaft position sensor can fail and not set a code.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

Let me know your thoughts and questions.

Take care,

joe