every time when I start my engine, there is this sound... dont know how to describe it, but usually goes away moments after I take my fingers off my key...
sounds like a fan of some sort... but its pretty loud.

however, sometimes this sound doesn't go away, so since its pretty loud, i just turn off the motor, and try again... and it goes away.

any ideas? I assume this is not the proper remedy for such a situation.

 

Could be your alternator mine went out and when it did it had a sound just like you described. I looked at the back of the alternator and there was some sparking the wire had lost some of its outer jacket. Well anyway the dual fans could be a problem too. Doubt it though because you would have some serious overheating issues if that were the case. Well anyway my alternator did the same thing and i did what your doing because after about a minute or two the sound would go away and sometimes it wouldnt make a sound at all just depended on the day. I changed the alternator and never heard it again i just had a little help since mine was doing some arching and sparking. Good luck i dont have anything else to say unless it was internal such as the valve train maybe some components came loose rocker arms tend to do that but usually have a clicking sound.

 

Could it be a starter that's wearing out and not disengaging from the flywheel properly? This would make an ungodly racket from the starter's gear being spun up by the running engine to speeds it was never meant to hit (or the entire starter motor if the overrunning clutch inside it isn't working). If that's the case, the pitch of the sound should change with the engine's speed if you rev it (gently, so as not to cause a bearing failure in the starter and send parts flying).

If not, I think you've gotta have someone else start the engine while you listen under the hood to see where it might be coming from. There are just too many possibilities for something that "sounds like a fan".

 

if I could guess, I'd say the sound is coming dead in front of me...

if that helps at all?

 

I think we have a winner!!

 

hmm, that doesnt sound good... is the starter in front of the driver?

i thought for some reason it was on the passenger side?

 

This could be way off but I thought I'd put it out there. Do Air Pumps make any noise when the car is first started? Mine never did but I think I remember reading that some do. I could be way off but thought I'd put it out there..... good luck with the issue
and yes the starter is on the passenger side

 

Yes my air pump made all kinds of noise until i disconnected it.