Q: Sounds like a small fan on engine when car off, not radiator fans.

asked by on

When I turn the engine off, a small fan stays on, causing the battery to die. But it's not the radiator fans. I've switched relays of similar kind for the fans and AC and it still stays on.

My car has 167000 miles.
My car has an automatic transmission.

Hi, thanks for writing in. The noise you are hearing is the emission control system performing a system test of the fuel tank vapor system. The system should run the test in less than ten minutes. If the battery cannot last long enough to finish the test before it dies then the battery may be bad and cannot handle the load and needs replaced. Have the battery tested to make sure it is not bad. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

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
  1. Home
  2. Questions
  3. Sounds like a small fan on engine when car off, not radiator fans.

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: No heat when not pushing on gas

You may have a clogged heater core that may be prohibiting the outer linings of the heater core to get hot. As you know, the heater core is a series of tubes that the coolant runs through that generates the...

Q: Car jerks when shifting into reverse gear

I think you are correct - the transmission is in "limp" mode. Have a professional mechanic check for problem codes to indicate what the fault might be. This is an important "next step" because that problem may not be with...

Q: Car overheating at light

I am going to assume you have a 2.2 liter engine with the air conditioning option on your vehicle, since you mentioned multiple fans. Both fans should turn on while the vehicle is running and the A/C is switched on....

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...