2006 V8 4x4 engine chirp/squeel

[cast-n-blast]

Hello T4R community,

I have been lurking around this forum for a while and love checking out everyone's rigs. Whenever I have questions I have usually been able to use the search function and find the answer with out emerging from the shadows to make a post.

I drive a 2006 V8 4x4 T4R and love it, it has 42K in miles on it and I have recently noticed that when I I get on the gas pretty aggressive at around ~3500 RPMs right before the truck shifts gear the engine makes a noticable chirp or squeel. Search has not yeilded much in terms of answers.

Anyone ever experienced this or know of someone who has? Any possible fixes? The truck did not make this sound until a few hundred miles ago and it is semi alarming.

Thanks for the help, this site an awesome resource.

cast-n-blast

 

[sonerick]

I'd start by checking the condition of your serpentine belt and its tensioner/pulleys. 42k is low-ish mileage for a serpentine belt to go bad, but who knows....

http://www.toyota-4runner.org/4th-gen-t4rs/98045-belt-sqeal-2.html

 

[HOJeepster]

I get that too when I really step on the gas, I don't think its something to worry about.

 

[ClockWork]

Right around that RPM is when the ACIS (Acoustic Control Induction System) activates. Mine does not chirp but there is a slightly audible change in intake sound. It is only noticeable when it shifts at that RPM and when I'm really listening for it.

The system is controlled by a vacuum.

 

[thirstyturtle]

I have the same thing, have had it since I bought the truck last year. I've pretty much narrowed it down to just being the large amount of air being sucked in by the intake, right when it shifts it just sort of squeals because it was sucking so hard and then can't suck in quite as much in the next gear. I'm not CERTAIN that's why but I'm almost positive it's the air induction making the sound. Either way, others have it so yay! it's not a problem.

 

[cast-n-blast]

Thanks for the info guys, glad I'm not the only one experiencing this noise. It is definitely more of a hiss than a chirp or squeal after hearing it again.