I need help idenifying next steps in troubleshooting a new engine noise:
05-09-2004, 06:30 AM
#1
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I need help idenifying next steps in troubleshooting a new engine noise:
<center><img src="http://pictureposter.audiworld.com/683/newnoise.jpg"></center><p>I have been driving the car hard all day yesterday at a lapping day - Pocono (PDA).
This noise started in the third session, and here is my best verbal description of it:
Only on full boost, most noticeable after 4,000 RPM, the car started whistling loudly like never before. When this started, I also heard a light metallic clunking noise. After a hundred miles, I no longer hear the clunking.
Back to the whistling sound. I have Stage II+ and I am used to the turbo spool-up sound, I have also driven this car or 50K miles. This is a brand new noise that was so loud that I heard it with my helmet on.
Since then I have visually inspected the TBB, checked for codes, and logged the car. TBB looks fine, no codes, and logs look ok too. Please take a look at the picture.
Finally I have a video clip, in which the noise is apparent to me, will see if you will be able to distinguish it. There are three clips, normal, and two with the mystery noise - please take a look.
Is there anything I can check do before going to an Audi mechanic? What are your thoughts on the problem?<ul><li><a href="http://www.startupracing.com/Movies/NewNoise.wmv">Video, please Save ***...</a></li></ul>
This noise started in the third session, and here is my best verbal description of it:
Only on full boost, most noticeable after 4,000 RPM, the car started whistling loudly like never before. When this started, I also heard a light metallic clunking noise. After a hundred miles, I no longer hear the clunking.
Back to the whistling sound. I have Stage II+ and I am used to the turbo spool-up sound, I have also driven this car or 50K miles. This is a brand new noise that was so loud that I heard it with my helmet on.
Since then I have visually inspected the TBB, checked for codes, and logged the car. TBB looks fine, no codes, and logs look ok too. Please take a look at the picture.
Finally I have a video clip, in which the noise is apparent to me, will see if you will be able to distinguish it. There are three clips, normal, and two with the mystery noise - please take a look.
Is there anything I can check do before going to an Audi mechanic? What are your thoughts on the problem?<ul><li><a href="http://www.startupracing.com/Movies/NewNoise.wmv">Video, please Save ***...</a></li></ul>
05-09-2004, 06:42 AM
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Hmmm...........tough to hear
Could you perhaps shoot another clip of the car on the street, with the windows up, or windows down at a lower speed, so the sound is not disturbed by other cars/noises?
I didn't hear anything resembling the "dentist drill" scream the turbos can make when they are damaged, but I'd like to hear it again.
It sorta just sounded normal, but louder. Perhaps an intake leak before the turbos? And since it ran fine, before the MAF?
I didn't hear anything resembling the "dentist drill" scream the turbos can make when they are damaged, but I'd like to hear it again.
It sorta just sounded normal, but louder. Perhaps an intake leak before the turbos? And since it ran fine, before the MAF?
05-09-2004, 07:07 AM
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Sounds exactly like the dentist drill/police siren sound to me. I'd say the turbos are on their way
out. :-( Then again, I know people who have driven for 20k miles with their turbos making that noise.
05-09-2004, 07:15 AM
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OK, great.........if the sound is sorta a metallic whirring sound only at full boost, then...
the turbo bearings have sustained a little damage.
There *is* a chance that if you have this sound and you take it easy on the car for a while, the noise will subside. I've seen a few K04's on A4's go through this, and then "heal" themselves in casual driving. To this day they are all running fine.
There *is* a chance that if you have this sound and you take it easy on the car for a while, the noise will subside. I've seen a few K04's on A4's go through this, and then "heal" themselves in casual driving. To this day they are all running fine.
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05-09-2004, 07:44 AM
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Honestly - it's probably your turbos starting to give up the ghost...
Mine started making this noise, and I switched back into stock mode and made it another ~10k before just going to Stage 3 (pre-emptive - turbos were still making boost, etc). My K03's *seemed* ok (the shafts, anyway), but I noticed small fractures in the K03 housing... I'll take pics and post, later.
On the other hand, my roommate (Johannes) has had that sound for probably ~30k miles, and he's still chipped, and still making boost. Granted, he doesn't really drive as hard as I do, and he hasn't gone to a track event since the noise started.
So.. your milage may vary - but honestly, I'd put money on the fact that it's your turbos. Could be some sort of FOD that has caused one of the impeller blades to start cutting thru the air differently - could be the shaft on one of them, starting to get a bit loose...
Sorry :-/
-T
On the other hand, my roommate (Johannes) has had that sound for probably ~30k miles, and he's still chipped, and still making boost. Granted, he doesn't really drive as hard as I do, and he hasn't gone to a track event since the noise started.
So.. your milage may vary - but honestly, I'd put money on the fact that it's your turbos. Could be some sort of FOD that has caused one of the impeller blades to start cutting thru the air differently - could be the shaft on one of them, starting to get a bit loose...
Sorry :-/
-T
