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front end rotating grinding noise
05-05-2011, 04:33 PM
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front end rotating grinding noise
Problem with my 2002 A6 3.0
Developed a grinding/rumbling/rotating noise on the drivers side front end. Noise occurs noticably above 45 mph....really not at lower speeds.
I thought it was the driver side wheel bearing...replaced at local shop... same noise. Took it back and shop said no doubt the noise is coming from the transmission...replaced transmission...same noise.
Any thoughts of other causes? doubt its a CV joint...not really at all a clicking sound.
Again noise above 40-45 mph driving straight or turning.
Developed a grinding/rumbling/rotating noise on the drivers side front end. Noise occurs noticably above 45 mph....really not at lower speeds.
I thought it was the driver side wheel bearing...replaced at local shop... same noise. Took it back and shop said no doubt the noise is coming from the transmission...replaced transmission...same noise.
Any thoughts of other causes? doubt its a CV joint...not really at all a clicking sound.
Again noise above 40-45 mph driving straight or turning.
05-05-2011, 06:22 PM
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Let me get this right...they replaced your transmission (their diagnosis) and you still have the noise? I hope you told them "thanks for the free transmission." If they didn't cut you a killer deal on that, you'd better realize they have no business being in car repair. Seriously, I'd find another shop. As to your grinding noise problem, I've seen goofy things make noises over the years...one tech (and I use that term loosely) took apart the whole rear end of a Toyota 4-Runner because of a "grinding" noise. Kept replacing parts and couldn't find the problem until I walked by and noticed that the back of the wheel/tire assembly had a raw mark on the back of the tire, into the sidewall belts. Turns out the E-brake cable had shifted when someone else did exhaust work and was now cutting into the back of the tire and telegraphing noise through the vehicle.
You need to knock down each of the possibilities, starting with the simplest you can think of. I.E. tire rubbing on something that floats into contact with the tire at 45 mph. Brake pads, rotors: small stones caught in them? Somebody crush the brake backing plate into a rotor? When did this noise start? Has it gotten worse with time? Is there some part on the engine that is making the noise at the revs you'd make at 45 mph? Can you duplicate it in neutral? Does the car have to be in motion? Ask and/or answer these questions and go from there. Good luck, tell us how it turns out.
You need to knock down each of the possibilities, starting with the simplest you can think of. I.E. tire rubbing on something that floats into contact with the tire at 45 mph. Brake pads, rotors: small stones caught in them? Somebody crush the brake backing plate into a rotor? When did this noise start? Has it gotten worse with time? Is there some part on the engine that is making the noise at the revs you'd make at 45 mph? Can you duplicate it in neutral? Does the car have to be in motion? Ask and/or answer these questions and go from there. Good luck, tell us how it turns out.
05-06-2011, 02:21 AM
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you can not hear any noise at idle....and really nothing until you get over about 4omph. Shop said that replacement tranny was bad and they will get a new one. I am all for that....but ...have my doubts. They swear when they ran it on their lift the gear box was the noise.
I to have been thinking about other causes. Noise started out of the blue about 1K ago (118K on car now) Not tires as i put on 4 new after noise started. when I apply brakes that does not staop the noise. When i turn the wheel for the most part it does not effect the noise...maybe slightly worse when a turn to left.
Could it be the engine? Although engine and tranny run perfect.
I to have been thinking about other causes. Noise started out of the blue about 1K ago (118K on car now) Not tires as i put on 4 new after noise started. when I apply brakes that does not staop the noise. When i turn the wheel for the most part it does not effect the noise...maybe slightly worse when a turn to left.
Could it be the engine? Although engine and tranny run perfect.
05-06-2011, 02:36 AM
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getting back to the actual noise...guess its not really a grind... it is really a rotating, grumble/rumble type noise ...i guess lol. starts slower at 40 and slowly increases the rotating should until about 60. Pretty steady. Its noticable to all in the car so its just not me being over sensitive. I guess maybe I should have taken it to the dealer? Come on guys I know with all the knowledge out there someone has had something like this.
05-06-2011, 04:28 AM
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quit replacting parts and diagnose. we cant do it here - get on lift, get things turning, listen, feel, use stethoscope. I cannot believe someone replaced a tranny on a lark! Why nto just mail us all $1000 and save the effort?
G
G
05-06-2011, 04:31 AM
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CV? Wheel bearing ( you replaced?), there's not much else there!
You need to diagnose whether it occurs with the engine revving but in neutral vs in gear. If in gear only, cant be the motor. Motor bone connects to tranny/diff bone, to CV to wheel bearing bone to wheel tire. You seem to have eliminated all of them. Methinks someone is sloppy. Something maybe out of alignment? CV flang not square? Subframe moved an placing side load? Th mind wanders.
G
You need to diagnose whether it occurs with the engine revving but in neutral vs in gear. If in gear only, cant be the motor. Motor bone connects to tranny/diff bone, to CV to wheel bearing bone to wheel tire. You seem to have eliminated all of them. Methinks someone is sloppy. Something maybe out of alignment? CV flang not square? Subframe moved an placing side load? Th mind wanders.
G
05-06-2011, 05:15 AM
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Is this a Quattro? If so, you might have a bad center bearing for the driveshaft to the rearend. I'm pretty sure there is a carrier bearing for the shaft. The fact that the shop replaced the trans and the noise was still there leads me to believe it's not the trans. The odds of 2 trannys being bad the same way has to be astronomical...
Last edited by Zaphodb17; 05-06-2011 at 07:36 PM.
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05-06-2011, 07:37 AM
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It is not a Quattro
Does not make noise in neutral reving engine
I have replaced the wheel bearing but done nothing with CV. Can the CV/flange/etc make this type of noise? Boot is fine.
Shop guy says he still is 100% sure its the tranny and will redo it again at no cost...like someone said on here...whats the chances of 2 making the same noise? Does not make sense to me either...but I am not the mechanic who is on the hook for this. The shop is a very well repected foreign car shop in Savannah. They do almost all high end vehicle repairs.
Does not make noise in neutral reving engine
I have replaced the wheel bearing but done nothing with CV. Can the CV/flange/etc make this type of noise? Boot is fine.
Shop guy says he still is 100% sure its the tranny and will redo it again at no cost...like someone said on here...whats the chances of 2 making the same noise? Does not make sense to me either...but I am not the mechanic who is on the hook for this. The shop is a very well repected foreign car shop in Savannah. They do almost all high end vehicle repairs.
05-06-2011, 07:46 AM
#9
How about getting the car up above 40, and using the tip to downshift one? If it's that specific gear, you will most likely have no more noise? If it continues, then you may be able to eliminate the tranny?
If you can get under the car, check your CV boots, as others have suggested. See if they're torn or ripped. Mine has been going for a while, and makes horrific noises when I turn (like popcorn popping...very loud popcorn), but I can see a fluky joint going bad in such a way that it is not immediately easy to diagnose.
Also, when you say above 40, are you sure it was the speed that did it? Have you tested it in different situations? i.e. - sometimes people live near the highway and they hop on the highway when the car is not yet warmed up, and others live a little further and when they get on, the car is warm. Maybe it is something warming up and a fan coming on or something? If this is the case, idling the car won't do it, unless you idle it until it is warm.
My gf's A4 had a metalic pop-pop-pop sound, which turned out to be the bracket that goes around the front motor mount that had come lose and would randomly vibrate at odd times. Maybe hitting some light bumps could help you find this...
I am having a hard time picturing a mechanic revving the engine to get the speedo up to 40 mph while on a lift...but I'm not a mechanic, what do I know?
Just some thoughts, hope it helps.
If you can get under the car, check your CV boots, as others have suggested. See if they're torn or ripped. Mine has been going for a while, and makes horrific noises when I turn (like popcorn popping...very loud popcorn), but I can see a fluky joint going bad in such a way that it is not immediately easy to diagnose.
Also, when you say above 40, are you sure it was the speed that did it? Have you tested it in different situations? i.e. - sometimes people live near the highway and they hop on the highway when the car is not yet warmed up, and others live a little further and when they get on, the car is warm. Maybe it is something warming up and a fan coming on or something? If this is the case, idling the car won't do it, unless you idle it until it is warm.
My gf's A4 had a metalic pop-pop-pop sound, which turned out to be the bracket that goes around the front motor mount that had come lose and would randomly vibrate at odd times. Maybe hitting some light bumps could help you find this...
I am having a hard time picturing a mechanic revving the engine to get the speedo up to 40 mph while on a lift...but I'm not a mechanic, what do I know?
Just some thoughts, hope it helps.
Last edited by jseklund; 05-06-2011 at 07:48 AM.
