Quick question:

In the mornings when starting my 2001 i30, if I turn the key to "run" for a few seconds before cranking the starter, a little electric motor hums for a few seconds, then stops. (it's not the automatic seat positioner.)

Is this the fuel pump that I'm hearing?

The reason I ask is this: If I get in the car and turn the key immediately to "start," sometimes it will take 3-5 seconds of cranking to start the engine as opposed to the immediate startup. If I wait a second until the humming stops, the car starts right up upon cranking.

Of course, none of this is 100% consistent.

 

Yes, most likely thats what you're hearing...if the noise is coming from the back of the car, like around the back seat area.

 

yes its your Fuel pump. that is the pump priming it self.

unless your really low on gas the car should start up fine even if you dont wait the few seconds for it to prime.

the tank gets pressurized w/air to make it easier to pump the fuel, while the fule pump pumps the fuel to the engine. When the tank is really low on fuel the pressurization takes a bit loonger cause there is more of a void (the space the volume of fluid would fill) to fill. That might explain the delay.

Its not reccomended to keep the fuel low as its rumored to cause premature pump failure.

 

I dont think he's reffering to the fuel pump in this one. Our stock fuel pump is pretty quiet. And it's especially hard to hear with the backseats in.

To the OP, if you turn the key while your foot is on the brake pedal, do you feel a light the vibration through the pedal also with the noise?

 

I'll have to check what you're saying about the brake pedal. The noise is coming from the rear, conceivably from under the back seat.

I leave for work at around 530 AM. It's so quiet at that hour that I often hear things I wouldn't notice any other time with "city noise" going on.

 

or the EVAP valve or Idle valve...? does a funny sound when you turn the key to on. i dont think anythign else should be making any noises. is there also a ticking sound... jsut get out and runn!!

 

Can't the electric motor mounts start to make a noise that this at start up and shut down when they are going bad?

 

In that case it is the fuel pump priming for sure. It's just odd that you hear the stock pump with the back seats in place. But I guess if it's completely quiet outside you would be able hear it.

 

that may be due to the climatic condition

 

OK team... turns out I was wrong.

The noise is indeed coming from the *front* somewhere near the firewall. Like others have suggested, it could be any number of things up there preparing for the startup procedure. (I speak like we're firing up a DC-3 airplane engine or something...)

Thanks all,
Murph