Auto Parts: Car noise, chrysler neon lx, chrysler neon

Question
Dear expert:
First question:
I have one 2002 chrysler Neon LX, 90000km. Recently, I always can hear there have a small noise like fly/bee flying at the front. It keep nosing especially at higher speed or hitting gas. It will disappear or quieter when city driving at low speed.  
Another question:  My car is automatic, and the fan seems run faster occasionally and make make louder fan's noise when I make the transmission on P (PARK). It usually last 5 seconds, and then it disappear by itself.  When the transmission on some other position, that noise never happended.
Hope you have time to solve my questions.
Thank you very very much.

Answer
Hi Clark,

First question. Does the buzzing sound seem like it is emanating from the audio speakers? My first thought is that the plug wires in your car or the spark plugs are getting old and the resistance is increasing which can defeat the 'noise suppression' in the plugs/wires. Typically this sound is heard when the engine RPM's are higher or more consistent, just like you are experiencing. Changing the spark plugs and/or plug wires should eliminate that issue.

Second question. When your vehicle is in 'Park' there is no expectation that the vehicle will be moving. The ECM knows this so when the cooling fan is cycled on, the computer momentarily locks it into it's fastest speed until it receives a signal from the core sensor as to the actual coolant temperature and if it is below a pre-set limit, the fan goes into it's 'quiet' mode. The ECM is programmed to do this if the selector is in 'Reverse' also, but not any other positions. As dumb as it sounds, the ECM takes no orders from the speed sensors in the vehicle to perform these operations even though logically, that would be a better way to work the system. But that's just my opinion.

Thanks for the question, I hope this information was helpful to you.
Fred
Knucklebusters Used Auto & Truck Parts, Inc.
www.knucklebusters.us
570-453-0910
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