Skip the auto shop - Our mechanics make house calls

Q: Car won't stay on for less than 5 seconds and makes a knocking sound.

asked by on

Car cranks and idles for less than 5 sec. Giving it gas last night while at idleing like at a stoplight kept it running, now that's not working. Knocking sound continuously while running. What could this be. Victoria_thompson15@yahoo.com

Hi there. The symptoms that you have presented sounds as if the fuel pump has stopped working. When the fuel pump stops working, the engine will start up and run rough and stall out. While the engine is running, due to the lack of fuel entering the engine, the engine will make a popping sound and a knocking sound which is the engine misfiring and trying to operate on very little fuel with a mass volume of air. Check the fuel pump relay and see if its clicking on as the key is turned on. If the relay is not clicking on, then check to see if there is power to the relay. If there is no power to the relay, then there is a break between the relay and the ignition switch. If there is power to the relay but nothing past the relay, then the relay needs replaced. If the relay is clicking but the fuel pump does not work, then check the fuel pump fuse. If the fuse is good, then either there is a break in the wiring between the relay and the fuel pump or the fuel pump has failed and would need replaced. If you need further assistance with your engine stalling, 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 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
  • Home
  • Questions
  • Car won't stay on for less than 5 seconds and makes a knocking sound.

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: honda accord will not start

Hello, thank you for writing in. In these situations always start with the basics. First, when turning the vehicle over to try and start it, a slow cranking speed may indicate you have a weak starter or battery. The starter...

Q: My truck will turn over but wont start. Its making a clicking noise and then shuts off, what should i do to fix it?

Hi there. Check the fuel pump relay and see if the relay has failed. If the relay is working fine, then check the fuel pump and see if its coming on when you turn on the key. If you are...

Q: Van stalled, ABS and brake lights went on, couln't be restarted

It sounds like your alternator may have failed. It is the alternator's job to power the electrical system while the engine is running, as well as keep the battery charged. If the alternator has failed, the battery will now take...

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 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...
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...