strange rattle from under car near front end, radiator fans?
01-22-2008, 04:45 PM
#1
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strange rattle from under car near front end, radiator fans? Not sure if it could be manifolds or maybe some kind of component of the radiator or fan or what not...car makes a strange metal rattle/ grinding metal noise when slowing down to a stop or first accelerating from a stop and while turning at the same time. I have noticed the noise only happens below 2000rpms--so whatever the noise is, it is happening because of heavy vibrations, since those engines have heavy vibrations at lower rpms. Anyone know what it might be? Almost sounds like it could be comming from 2 areas...towards the very front of the car near the radiator fans, and also directly under the drivers seat....I have looked under the drivers side of the car and I dont know what it could be, I see brake lines and thin metal tubing and manifold covers made of metal as well...it could be anything...its just strange that it only does it at lower than 2000rpms....and then stops once the car starts going. I have pulled up next to a camaro one day and that car did the same thing in idle and at a stop...so it must be kinda common...theres gotta be someone on this forum with the same problem...HELP! 
01-22-2008, 06:23 PM
#2
I have the same thing, it is a loose heat shield somewhere. At those lower RPMs is where the resonate frequency of that stuff is so that is why it rattles right then. No big deal except for the annoying tiixxzzxxtxxzzxxttt sound (lol that looks weird on the screen 
). When the weather is nicer I'm planning on crawling under the car and finding what is loose because it drives me nuts.
). When the weather is nicer I'm planning on crawling under the car and finding what is loose because it drives me nuts.
01-22-2008, 09:36 PM
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haha ya its crazy annoying, drives me nuts. I'll have to check it out. I've seen those shields before and thought it might be them...its just a matter of which one is it! lol
01-23-2008, 12:53 PM
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well once you start giving the car gas from a stop and start to increase speed, the rpms also go up which the noise will get a little louder but then suddenly stop...which is why i said its wierd how it only happens at less than 2000rpms b/c of the rough vibrations at lower rpms....like if i were going about 30 mph and the car upshifts to a higher gear and the rpms stay low below 2000 rpms and i hold the gas peddle in like a constant speed keeping the car from downshifting, it makes the rpms stay below 2000rpms which the noise will just go crazy and stay and keep making the noise until i give it more gas and make the car shift or rpms go above 2....which is why my theory is just somethin vibrating like crazy due to low rpm vibrations...
if it were a wheel bearing...i dont know much about that, explain that a little more...what it is and where its at exactly and what it does....if possible...im tryin to narrow things down and problem solve and eliminate the "could be's" to find it...haha...
thanks guys!
if it were a wheel bearing...i dont know much about that, explain that a little more...what it is and where its at exactly and what it does....if possible...im tryin to narrow things down and problem solve and eliminate the "could be's" to find it...haha...
thanks guys!
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01-23-2008, 10:35 PM
#8
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A similar rattle/buzz in my '01 V-6 turned out to be the CAT going bad. The stuff inside will start to clump up. The way I would describe the sound was that I thought there was a heat shield under the seats that had a piece of gravel or something on it that was vibrating and causing the sound. It would come and go. Mostly at idle or just starting out. About 2 months later I started getting the SES code for bad CAT.
01-23-2008, 10:41 PM
#9
A similar rattle/buzz in my '01 V-6 turned out to be the CAT going bad. The stuff inside will start to clump up. The way I would describe the sound was that I thought there was a heat shield under the seats that had a piece of gravel or something on it that was vibrating and causing the sound. It would come and go. Mostly at idle or just starting out. About 2 months later I started getting the SES code for bad CAT.
Anything you gotta do after gutting a cat (dang that sounds inhumane or something lol), would it trigger a SES code that needs tuned out or what?
01-23-2008, 11:06 PM
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I turned the SES light off with a scanner before I turned it in and the next day drove off with a pristine '02 WS6 with 14,000 miles on it, for $14,000 after trade. Fully loaded, almost new car. I did not get arrested for stealing, but I felt like I should.
02-07-2008, 02:32 PM
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I've been tracking down a similar rattle issue in my Z28 which led me to this thread. Guess it's time to check the cat cuz everything else was checked.
