I only hear it with the windows down while giving the car a sudden acceleration around 3k rpm. The sound is very brief and reminiscent of a slight chirp/whistle coming from the engine bay. The sound seems to be most noticeable when the car is being punched in 3rd and 4th gears. I don't notice any other adverse effects such as hesitation and stuff it just sounds like a turbo spool but only for a slight second when you give the car lots of gas. I thought it could be th PCV, but I don't notice any other ill effects..any ideas anyone? I know it's hard to diagnose sounds I was just wondering if anyone else noticed it. The car is an 05 6MT non rev up with about 50k miles.

 

hmm good call..I thought about that but didn't think stock airboxes make noise

 

50,000 miles have you replaced the belts? If not do so. One is slipping.

 

i have the same problem with my stock airbox. i changed it ang got an injin cold air intake and it still gose the same thing. my cousin said it is the throttle body but i kind of dout that.

 

This makes sense, especially since it is at the RPM range when the power is coming on.

 

my 06 started doing it after 40k mi...i had a JWT pop charger on it..never heard it...then all of a sudden it starts to do it past about 3.5k rpms

 

hey guys,

interesting about the belts....i just changed mine and they were squeeling terribly so tightened both of them. The squeeling went away and car is driving great apart from me hearing this chirp sound under heavy load as you described. i thought i tightened them to tight! Now im thinking i havent tightened them enough lol. My car is completely stock so something tells me it is the belts. Will tighten further and let you know how i go.

 

six year dead thread revival. did you replace the belts?

 

i know ....original posters are probably grandparents by now lol.

Yep replaced the belts with genuine nissan ones - both of them. i was just down at the workshop and they said that the aircon belt could do with some tightening but the other is fine. So will tighten this lower aircon belt on the weekend and post back.

 

tightened the belts - chirp still there. maybe it is the MAF sensor?! perhaps i need to clean it or get a new one. Has anyone done this and the chirps actually gone away?

thanks.