Here's another good mystery sound to figure out!

[saunders80]

well lets see.. 02 rodeo auto 3.2 2wd...since around the major tune up mark of 100,000 miles (plugs, timing belt,etc..) i have found that isuzu really must have got a good laugh at the poor people that bought the newer gen rodeo's and such.. btw love this forum jus wish i had found it alittle sooner.. but anyway back to the mystery noise, quick run down spark plugs, timing belt, water pump, egr cleaned and tube, fuel filter, air filter, mas cleaned, oh 02 sensors replaced when cats burn up due to the wrong spark plugs making veh run rich and misfiring without a constain code.. thanks autozone! so anyway after all that the odeo runs pretty much fine.. except this sound that only happens when i take off hard or punch it to pass another car.. it sounds like thin metal viberating or hell i don't know.. ok maybe like the sound central air unit's on a house make when defrosting itself (i think?)... i 95% sure it's in the intake somewhere.. tried to research but only thing i got was very little info on double butterflys (refer to as poor man's supercharger) and ideas would be great! oh and i'm above average shade tree DIYer so thanks for reading my novel here!opcorn:

[inafogg]

exhaust heat shield loose or stone rattling on it??

[saunders80]

oh i could only pray its that simple!!!!! check it out today

[amigo-2k]

That is my guess too. I had one that was 1/2 way rusted off, that I hosed clamped back on and the noise is gone.

[anthonyn]

It could be pinging. Next time you meet a hill, accelerate hard and see if it pings. Or try higher octane gas.

[Cat Fuzz]

First thing I thought was pinging or pre-detination. This happens when the air-fuel mixture in the combustion chamber explodes before it's supposed to. There are many reasons why this would happen but the reason here could be a MAP sensor that isn't responding quickly enough to the sudden change in manifold vacuum and the ECM is compensating late. Unless '02s don't have a MAP, then I will have to think of something else.

[FL 3.2L]

You have the right plugs in there now? Maybe the carbon buildup from the wrong plugs has you pinging.

[saunders80]

yes i have all exact oem parts (that affect electronics..) back on it.. its diff not ping or and anything like that.. the sound is more closely matching that of a heat shield loose or som.. the motor is strong and smooth, it's jus when i acel hard or it whines out in passing gear i hear this ignoring sound.. i jus want to know what it so i dont spend another 2k in frigging parts to fix something minor now..i wanted to check it out last night but got side tracked.. try to look for it today.. again thanks a lot for the input..

[saunders80]

checked out the heat shields and eveything is tight.. so the mystery continues!!!!

[anthonyn]

Originally Posted by saunders80

checked out the heat shields and eveything is tight.. so the mystery continues!!!!

I still think you're experiencing pinging. Pinging can sound very different on different vehicles. Sometimes it's like rain on a tin roof. Other times it sounds like the tinkling of little bells. Why not just fill up with Super unleaded next time, and see if there is any change at all.

[saunders80]

ha lol trust me when i say its not pinging... i've been working on auto's long enough to know what pinging is... this is definitely a first time sound that i have ever and everyone around has heard.... i'm willing to bet... its somthing inside the intake because its coming from that general area.. and it only happens when there is a high velo of air coming into the motor.. pinging is more valves rattling and such.. positive 100% sure it's not that... it's a wincing sound.. there is nothing i can really compare it to.. think thin flexible metal air hose blowing at it from the side making it vib.. best i can do to describe it.......thanks for the input though

[saunders80]

well i guess i better call mystery incorp. maybe scooby can sniff out a clue!