I have a 99 4runner, 3.4 liter, 4x4, AT, with 110,000 miles.

I hear a slight chirping under the hood. I hear it more when it is cold but still hear it a little bit after it is warm. Sounds like it is coming from around or behind the pulleys. Anybody have any ideas what this might be? I tried a search but nothing exact.

I am planning on getting the timing belt and water pump done in the next few days/weeks as a preventative measure since I just got this vehicle. Thanks

 

number of things.. belts goin bad, fan clutch is goin bad, you got a cricket in there, you ran over something weird. spray your belts with wd-40, if it stops, then its your belts.

 

I once had a field mouse remodel my airbox into a nice studio apt with central air..

 

lol happened to my buddys honda. but they made the entire engine bay a studio apartment. and made the engine furniture. the wires were all cut up, air cleaner was all chewed, there were a couple dead mice in the carburator, lol

 

I've got the same thing, not a mouse, but a chirp. I didn't notice it until it started getting cold out and it hasn't gotten any worse......and it doesn't do it when it's warm (engine or ambient) so I've just let it go. Honestly, I just haven't had time to dig into it, I'll probably take a look tomorrow since it's finally going to be nice out. Im going to install my H4's and Hella 500's tomorrow (Hey...everybody else was going on a tangent, Lol)

 

ive got the same problem in my runner, go grab some belt conditioner and give your belts a spray, if it stops, theres your problem. The squeak can be caused by a bad belt or just cold weather.

 

Is the belt between your engine and alternator tight???

Also, I noticed that your4Runner has the 3.4V6 and not the 4banger, so in that case, it's not the hamsters getting hungry

 

I had the same noise a few years ago and it was my driveshaft and ujoints. They just needed some grease.

 

ok, well i will make sure I check the belts and spray some WD40 on there. the u joints will be lubed today as well but it doesn't sound like it is coming from there but will check cause it probably needs it anyways.

 

i thought wd40 was bad for belts?? i too have the same chirp when it is cold usually between 900-1100rpms it drives me nuts!!! but i just recently had new belts and water pump put in, before that i had no noise.

 

I broke one of the clips that secures the grille while working on the front end of my wife's 4Runner. Couldn't figure out where the chirping noise was coming from until I pressed against the grille while the vehicle was idling and the noise stopped.

 

Chrips in that area seem to always be a sign that the waterpump is goingo out. It's a bearing thing.

 

that is the general area it is coming from. it will be replaced within two weeks along with the timing belt. i hope that remedies the problem.

 

doesnt the pulleys make a chirping noise when they start to go bad? i am having the same noises and when i sprayed belt cond on them they stopped briefly. i think its the power steering belt. either say i should get my parts in from Yota of Dallas by tomorrow. then i am going to call around for quotes for labor

 

thats funny cause my chirping started after i had the timing service/water pump replaced i also have a new alt and alt belt as well.

 

Is this really a PROBLEM? Take off your belts, wash them in soap and water, dry, reinstall. Don't go sraying crap all over your belts. That's rediculous. WD40? What kind of brilliant scientist came up with that one?

 

Well I have the same noise, and it seems to be comming from the power S. unit. The problem is, it only does it when it is cold out. But I'm going to have it looked into on my next service. I also have all new belts as well as a new water pump.

I for one, would never spray WD40 on my belts. Dosn't seem like a good idear to me.

 

.......probably because it isn't a good idea.

Fix the problem, don't band-aid things or you'll like make the situation worse than it already is.

 

Hey I have an idea, take it to the dealership, spend too much on parts, then run some sea foam through it, and top it off with a full synthetic oil change. I just figured I'd say it first before the other idiots did.

 

LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!