Q: My car is still running after turning it off.

asked by on

I just replaced the battery yesterday. I went to work got there with no problems. I parked it and turned it off. But it sounded like it was still running, I tried to start it again and it wouldn't start. It ran with the car being off for about 10 minutes and then I started to see smoke after about 12 minutes it stopped running but still wouldn't start back up.
My car has an automatic transmission.

Hi there. The noise that you are hearing is commonly known as ’Dieseling’. When this happens, check the ignition switch alignment and see that the switch is turned completely off. If the switch is turned off, then while the engine is still trying to run, disconnect the power to the ignition coil pack and the engine should stop running. If the engine stops running, then there is power feeding from the ignition switch to the ignition coil after the switch is turned off. If this is happening, then the ignition switch needs replaced. If the engine continues to run with no spark, then there is too much carbon deposits in the combustion chamber. I recommend putting sea foam in the fuel tank, the engine oil, and the vacuum system, but one section at a time. This will help clean up the carbon deposits and allow the engine to stop dieseling. Carbon deposits get very hot and stay hot for a long time. When fuel is entered into the chamber, the carbon could ignite the fuel at an earlier time, or even after the injector has stopped running. Oil that has fuel vapors in it will continue to burn when the carbon is hot, keeping the engine running. If you need further assistance with your engine running after turning off the ignition, then seek out a professional, such as one from Your Mechanic, to help you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. My car is still running after turning it off.

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: When I go over 60 my car start jerking and abs comes on dash

This may be an issue of a faulty ABS control module or possibly faulty wheel sensors. The ABS control module controls the activation of the ABS system based upon inputs from the ABS wheel sensors. When this module is not...

Q: Car stopped working - 2002 Dodge Stratus

Hello there, many faults will cause your 2002 Dodge Stratus to die while running and not restart. There two types of problems that will cause this, they are either electrical, or fuel-related. Common fuel problems are the fuel pump, fuel...

Q: Advice on which transmission fluid to use

Hi there. It is fine to use this in the engine, but I would not use it in the transmission. This transmission is very temperamental, and if you do not use the genuine Honda fluid you will almost certainly have...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.