Weird sound from engine following RPM.
 

Hi guys , I am new to this forum and would need help.

I recently bought a 98 Avenger 2,5L V6 Automatic with 190.000 km on it. ( around 118,750 miles ).

I paid the car 950$.

The problem is:

You know when you reverse a car the sound it makes ? My car does it all the time. It follows my rpm and does it at idle too.
Sound like this http://www.youtube.com/watch?v=GlTKM8wCMU4 ( not the engine itself but the weird sound )
What could it be ?

Thanks.

evap solenoid ?

Forgot to say the car works well , Stay idle perfectly, Starts good and Doesnt have the check engine light on.

Evap solenoid

I will look that , Where is it located ? And is there a way i can test it to see if it properly works ?

I just recorded the sound my car makes. here it is http://www.youtube.com/watch?v=fdiS4sketxQ

This is a cold start , Not really cold outside ( like 10 celcius ) but the car has not run today.

I found out where the sound comes from , But i dont know much about engines ( always willing to learn more ). This is the part that does the sound



http://img855.imageshack.us/i/img001...042911142.jpg/

http://img4.imageshack.us/i/img00156201104291114.jpg/

Thats BAD .. under the plastic cover is the timing belt ... you might have a bad tensioner /bearing /or the belts coming apart.
The 2.5 is a Zero clearance motor if you loose the timing belt ot even skip 3/4 teeth the motor will destroy itself

Thanks. I dont use the car alot but will still make it a priority. What is the name of the part showed in the picture ?

The Plastic part is the timing belt cover

what i mean is the part that has the belt on. Is it the A/c Compressor ?
Oh and i checked the belt and it looks good so it might be the bearing or inside de compressor something is rubbing. I just learned that my friend has a old stratus that has been accidented but the engine still works on it so luckily the parts i need might still be good.