do you have a whistle sound coming from 3.4 v6 engine during acceleration?

anything is possible, but I have heard all sorts of manner of belts slip and pulley bearing squeals but nothing like this type of noise

pulleys checked out ok and belts are all good and not loose

i am thinking its something like this in the exhaust system but not sure how to go about checking it and I don't want to start replacing every gasket from the heads to the tailpipe. not to mention its looks like a supreme bitch to get to any of that stuff much less replace it

 

can you replicate the noise at all revving the engine in neutral/clutch in?

 

just tried this a little while ago and not really a whistle but it did have the slightest little bit like an exhaust leak sound but just for a second when I step on the gas hard but I cant tell if its under the hood or under the floorboard but it is from near the engine area

 

I would guess that it's something with the intake, but if your truck is manual it could be the throw out bearing. Mine made a similar squeak noise when ever the clutch wasn't depressed until I replaced it.

 

its automatic

air filter box was left open, then air filter was removed, then air filter was removed and the air filter box was left open, and non of that changed anything with the noise so I would think that "should" eliminate the intake system

 

yeah unless there's a loose hoseclamp or rotted out rubber line somewhere causing a vacuum leak, you can check for vacuum leaks using an unlit propane torch. i don't know for sure but i don't think exhaust leaks typically whistle so much as cause excessive exhaust noise.

if you can't replicate it in neutral by revving the engine i'd almost think its going to be driveline related. maybe driveshaft/ujoint vibrations? driveshaft bearing?

no oil leaks or plugged breathers anywhere?

 

well the video didn't work, the surrounding noise is too loud so it doesn't come across on the mic.

it was the same exact noise as the 18 wheeler was making next to me when his exhaust system was accelerating.

its definitely an "air" noise and nothing mechanical, that's for sure, I know very well what mechanical noises, squeaks, squeals, bearings, and belt noises sound like

I can hear something like a quick exhaust leak or "blurp" at first quick acceleration when parked but not the whistle.

it seams to make the noise most from above 20mph and up and under 20 its not as easy to get it to make the noise.

I guess i'll have to change the donut gaskets and see if that cures it but that will have to wait for cooler weather.

I was just hoping someone who had the same issue and could tell me what it was for sure. im guessing its the donut gasket since it flexes when you accelerate so i'll try changing those first, plus I would think I would be able to hear if it was a bad manifold gasket but its quiet as a mouse and there are no signs of any leakage from the exhaust system anywhere

 

that 18 wheeler probably has a big ass turbo on it making the whistling lol

no intention of argument but just throwing it out there, prop shafts, drive shafts, etc can make noises that sound just like an air whistle surprisingly. my dads awd acura tl had a whistling noise (not whining or squeaking but sounded like someone blowing air over the lid of a jug) driving him crazy for months, took a few trips to the dealership but they finally diagnosed it has prop shaft or center bearing something like that. they replaced it and its perfectly quiet now

really hard to diagnose this stuff over the internet of course so if your suspicion is the exhaust than go down that route and see what you ccan find, good luck!!

 

maybe spray your exhaust down with soapy water while the truck is running and plug the end of the tailpipe with something while youre under the truck and see if any air is blasting out of the suspected joints/gaskets

edit: i guess some people use a shop vac on the blower setting instead of suction to pressurize the exhaust without running the engine so you dont burn yourself or whatever

 

that's not a bad idea don't have to get burned on hot pipes either

well that's the noise im hearing

if its the drive shaft or bearings its a sound I never heard them make before?

no vibrations, clanks, clunks, or any noise issues with anything

not willing to rule anything out but it sounds like a high pitch jet engine sound air noise to me.

also the whole truck is bone stock oem from bumper to bumper

 

seafoam your truck to find exhaust leaks.

 

I'm going to guess its your turbo - it's supposed to do that.

 

I am having the EXACT SAME issue. 2009 double cab, TRD sport. Though I do also get some vibration. Taking it to my mechanic tomorrow. Feels like drive shaft/ bearing/ u joints to me, so I'm gonna have him start there. Very irritating and mildly disconcerting.

 

Hi Keakar. Just a thought: was your air intake customized at some point? I know my stock air tube has a resonator box on it that may be designed, in part, to cut noise. Some who have the K&N filters mention increased noise.

 

I believe its the exhaust system of the 3.4L Tacoma's. Whistle sound comes out from the exhaust when accelerating.

 

I had an exhaust leak at the donut gasket which was tricky to diagnose because you'll only hear it under load. However, it was not a whistling noise in anyway, it was clearly an exhaust noise. My truck sounded like a NASCAR when under load lol

 

hadn't thought of that but i'll need a helper while I chase the smoke lol

good idea but I don't have a turbo or a super charger, its bone oem stock

nope, its bone oem stock

I was wondering if that might be the case since I see lots of posts about it on other forums with the first gens and also the same issues reported with the second gens too

see, that's what gets me, its quiet as a mouse with no exhaust noise at all so that's why I created this thread thinking it doesn't make sense to be an exhaust "leak" even if every sign says its exhaust related and it seams to mainly do it most from 20 mph+ but not so much under 20 mph and if you get fully on the throttle it doesn't do it so its only in the mid throttle range when it happens.

so everything I can diagnose is telling me its not an intake issue or and exhaust leak either and the truck is running smooth and getting good mpg with no EL codes or anything

this intense heat makes spending time trouble shooting this hard since I cant take being out in the heat for long, not to mention its hard to diagnose a noise that is only happening while driving it.

 

throtle body spacer? i bought my dodge dakota and it made that noise causing me to spend months searching and it turned out to be a 1/8 inch thick plate betwen the throttle body and the intake manifold that id asumed was a factory gasket till i saw the logo on it when i went to clean the TB one day...put a factory O-ring in and the whistle went away. no the air filter being in or out makes no difference to the spacer noise.

 

I have no throttle body spacer but it definitely wont hurt to replace the TB gasket, that's something cheap I can do just to see if that's it. that and test the whole intake system for leaks

 

Have you changed an O2 sensor recently? I changed mine, but honestly don't remember if the noise was present before I changed it. I still have the whistle. Mine occurs just about the time I hit 60 MPH when accelerating. goes away as soon as I'm at steady speed.