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Audi R8 V10 Coupe 2010 R-Tronic
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Discussion Starter · #1 ·
Hey guys, started driving my new-to-me 2010 R8 V10 R-tronic for about 5 months now and all seemed well until yesterday morning when I started the car and immediately noticed a very audible whine/hum from the inside of the cabin which seemed to emanate from the center console area and loudest under the shift lever. Initially thought it was AC related but the noise persisted even after I shut the AC off and left the engine idling.

Took it for a short drive and the noise seemed to disappear at elevated RPM's and comes back wailing right when I slow down and come to a complete stop. Propped the rear hood up to listen to the engine but it wasn't apparent and was exclusive to the interior once I closed the door. I revved up the engine in neutral and held it at 2k and then 3k and in both ranges the noise went away but comes back once the RPM's drop down to idle.

I will try to capture the sound on video and I hope it doesn't get drowned out by the normal engine noises and aftermarket exhaust. So far has anyone encountered this similar issue with their V10's? And on a side note, AC works fine and blows cold almost instantly when switched on.

Thanks guys and great to be on this forum. I have documented various DIY's on the car and will be categorically posting them soon.
 

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Discussion Starter · #2 ·
Audi R8 V10 Whirring Noise

Audi R8 V10 Whirring Noise Rev Up AC Off

Two videos I managed to capture which had the audible whine/hum provided that you turned your volume up. Has anyone heard a similar noise before?

An observation I have made so far is that the sound is always present as long as the engine is running an its pitch remains the same regardless of RPM. AC operation does not affect the noise and the only way the noise stops is upon engine shutdown.
 

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Discussion Starter · #3 ·
As an update, I've sent the car to an independent Audi workshop and they informed me that the sound is originating from within the AC compressor and is reverberating along the AC metal lines that pass through the center tunnel which is why I could hear it as if it was coming from below the shifter lever. Could be a sign of failing internals inside the compressor but for the time being, the AC still blows cold. I was advised by the mechanic to continue using the car since the noise was generally minor for the time being and to only replace the compressor in the event the AC stops working.
 

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Sound like good advice. No point in replacing stuff untill it needs it.
 

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Discussion Starter · #5 ·
Well that's the current approach taken now and it has led me to be a bit more light footed in the time being. Not saying I'm enjoying it right now as it's always at the back of my mind. But I agree with you.
 

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The repair cost will be out of your pocket I assume, thats too bad.

Do remember that if the compressor is failing internally it can be shedding debris (metal) into the system. There should be a coalescent filter that will help catch it, and the receiver drier is typically changed with the compressor (on standard systems) but that debris can get into the evaporator core, condensers, and the lines which will need carefully flushed to remove it.

But the system is working... so that noise could be in the direct drive system to the compressor, and moderately easy to fix whereas you have a V10 and "good" compressor access.

If the compressor was failing the system would struggle to pull down the high side pressures as the system functions, an AC specialist would be able to read his gauges and tell you a general idea of the compressors efficiency.

I have heard a death rattle from an AC compressor failing internally, it sounded like a tiny rod knock.

Just some further thoughts for you!
 

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Discussion Starter · #7 ·
The repair cost will be out of your pocket I assume, thats too bad.

Do remember that if the compressor is failing internally it can be shedding debris (metal) into the system. There should be a coalescent filter that will help catch it, and the receiver drier is typically changed with the compressor (on standard systems) but that debris can get into the evaporator core, condensers, and the lines which will need carefully flushed to remove it.

But the system is working... so that noise could be in the direct drive system to the compressor, and moderately easy to fix whereas you have a V10 and "good" compressor access.

If the compressor was failing the system would struggle to pull down the high side pressures as the system functions, an AC specialist would be able to read his gauges and tell you a general idea of the compressors efficiency.

I have heard a death rattle from an AC compressor failing internally, it sounded like a tiny rod knock.

Just some further thoughts for you!
Isidore, thanks for the advice and insight. I do believe that something is failing in the direct drive somewhere between the overload protection pulley and the internals of the compressor as the noise is rotational. A sinister tell tale sign that made me lean towards impending compressor failure is that the noise goes away as soon as the AC starts blowing ice cold. Could be lubrication related? You're right that any repair cost would be out of pocket for me as the warranty has long since expired.

My last ditch attempt as advised by my mech would be to perform an evacuation, flush, vacuum and refill of the AC system using his automated machine. The hope would be that the noise can be alleviated by replenishing the compressor with new oil and refrigerant after the lines are flushed a couple of times with his machine. The process may also confirm if the compressor is bad depending on how the used oil purged by the machine looks like (metal shavings etc.).

From the way I see it, this may give the compressor a better chance of surviving a bit longer and I don't see any downsides to it. Besides, I was only quoted $110 for the whole flush job so it's a bit of a no brainer step to take.
 

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Great advice by your tech, he will know the health of the rest of the system by placing it under a vacuum. Data you can use now, rather than if the compressor did fail you'll not necessarily know.

Also agree about a replacement of the pag oil, may buy you some time!!
 

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Discussion Starter · #9 ·
Update:

Got my tech to perform an AC evacuation, flush and recharge using an AC service machine. The result is that the compressor noise has disappeared for now which leads me to believe that this could be a temporary fix and that there is something mechanically wrong with the compressor but the gauges were showing healthy high pressure and suction readings comparable to a healthy compressor.

The tech showed me the purged oil and it didn't contain any metal particles but was a it was dark olive green colour. On the plus side, the AC is considerably colder than it was prior to the service and only costed me $80. With the system recharged with fresh R134A and new Denso compressor oil, it does give me peace of mind to a certain extent to continue using the car and I consider this issue a NFA (no further action) required for now.
 
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