General Tech Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.

2000 A6 2.7T Intermittent Noise Problem

Thread Tools
 
Search this Thread
 
  #1  
Old 02-04-2010, 01:34 PM
johnnysd's Avatar
Junior Member
Thread Starter
Join Date: Jan 2009
Posts: 5
Default 2000 A6 2.7T Intermittent Noise Problem

I have a 2000 Audi A6 2.7T (twin-turbo)

I am having an intermittent noise that I have not been able to diagnose or get repaired. Here is a description, it is a little strange

1. The noise is very much like a fan vibration mostly like the blades of a fan are clicking against some obstruction or the fans are clicking against the fan housing or frame. It's not exactly like that but close. There can be a little bit of a "flutter" to the sound sometimes and it can vary in intensity and volume level

2. It does not proportionally scale with engine RPM. It does go up a bit, but not in a direct relation which is why I initially thought it was the cooling fan (may still be)

3. It is very intermittent, and there is no direct causal event that triggers it. The noise can occur every day for a while, then not happen again for a week sometimes 2.

4. When it happens it always goes away at some point. When it goes away the engine sounds perfect and it drives excellently at all times. One very slight exception to this is that there does every once in a while seem to be just an extra little titch of turbo lag

5. It can go away in several ways:
A. High RPMS at idle will often clear it (i discovered this the first time to a repair shop
B. Sometimes it will go away all by itself in normal driving but not often
C. 100% of the time, if it is making the sound still when I stop and I leave the car off for an hour or more, sometimes less it will go away

6. When the sound goes away from a cold restart it is a little different than the other ways it goes away. When I first start the car (it starts great) it makes the same sound but noticeably louder and with a slight rattling element. However, 100% of the time the sound goes away within 15-20 secs.

7. I HAVE taken it to two good mechanics. Both mechanics initially thought that it was "fan related", but as in 6 above when they turn the engine on later the sound goes away and they are not able to make it occur again while they have the car in their shop.

So I was wondering if anyone has any thoughts on what it could be or maybe have seen this before and know what it is. It has been like this for probably 6K miles.

It does not burn any oil and oil level is correct, and does not overheat or get hotter per the gages when making the noise. Outside of the noise the car runs great. It is also a new engine put in around 12K miles ago when the previous engine threw a rod, and this engine had 45K on it. The water pump and timing belt were replaced new as part of the engine replacement.

Look forward to hearing some thoughts.
 
  #2  
Old 08-16-2010, 03:50 PM
99_A6_Avant's Avatar
Junior Member
Join Date: Jul 2010
Posts: 3
Default

Was this resolved? What was the cause?
 
  #3  
Old 08-16-2010, 07:13 PM
johnnysd's Avatar
Junior Member
Thread Starter
Join Date: Jan 2009
Posts: 5
Default

Originally Posted by 99_A6_Avant
Was this resolved? What was the cause?
Not really. It has only happened like twice in the last 4 months though. I think it might be gas related, I stopped get any gas from a local supermarket and that roughly coincides with the stop of the sound for the most part. THe last time when I get my oil change the guy said that the "sound" my car makes is a stuck valve and I need their valve flush. Not sure if there is any truth to that though.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jarak01
B5 Models
0
08-26-2011 06:28 AM
dmillrod
Audi A6
12
05-18-2011 12:15 PM
johnnysd
Audi A6
1
02-05-2010 04:35 PM
Bmw7even
General Tech
1
11-27-2008 12:00 PM
rollinon19s
New Member Welcome Area
2
09-21-2005 02:28 AM



Quick Reply: 2000 A6 2.7T Intermittent Noise Problem



All times are GMT -4. The time now is 05:58 AM.