Audi A6 The mid-sized Audi A6 model offers more room to the driver and passengers over the A4 line.

Diesel-like sound

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Old Mar 16, 2009 | 11:43 AM
  #1  
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Default Diesel-like sound

Well, it is not accentuated, but at idle the engine just doesn't sound right.

What was that you guys were saying it may be culprit for the noisy engine: the intake manifold sticky valves, or the cam chain tensioner?
Or it could be both?

Thanks.
 

Last edited by chefro; Mar 16, 2009 at 04:26 PM.
Old Mar 16, 2009 | 12:20 PM
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Cam chain tensioner probably... If it only chatters after starting the engine for a few of seconds, then it is normal. If it sounds like that all the time, then I would think it is your cam chain tensioner.
 
Old Mar 16, 2009 | 01:21 PM
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It is pronounced when starting the car - one may really think I have a diesel, then it fades away a bit as it warms up but still it doesn't sound right.

I guess I'll have to order a cam chain tensioner, if I can find it. (Is there a different name for it?)

Also... I came across a write up by someone who replaced the check valves.
Apparently, these two "non-return valves" are also responsible for some engine noise.

The person lists as needed parts:
Parts Required:
Head -> intake manifold gaskets (set of two)
EGR -> intake manifold gasket
Valley pan gasket
Check valves (2)
Throttle Body -> intake manifold gasket (optional)
3/16" (~3mm) ID rubber vacuum tubing -- about 1 foot (30cm) should do
1) If I want/need to replace the two "Check" valves, is there any other commercial term they go by? I can't seem to find any part called so.
I came across Intake Valves, but it isn't specified how many are required per car.

2) Is the EGR-intake manifold gasket he talks about this:


3) Since I would have to remove the intake manifold, beside the two (2) Lower Manifold to Cylinder Head gaskets, and one (1) Upper to Lower Manifold gasket, would I have to get the Exhaust Manifold to Head gasket as well?

By the way, tks HX.
 

Last edited by chefro; Mar 16, 2009 at 04:27 PM.
Old Mar 16, 2009 | 01:52 PM
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Valve lifters?
 
Old Mar 16, 2009 | 02:17 PM
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The lifter appears to me as being more of a pulley than a valve.
 
Old Mar 16, 2009 | 02:27 PM
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here's something:

Name:  TSBCheckValves.png
Views: 164
Size:  399.5 KB
 
Old Mar 16, 2009 | 11:38 PM
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Originally Posted by chefro
...... would I have to get the Exhaust Manifold to Head gasket as well?
doh...nevermind....that's actually below the cylinder head, bottom side of the engine.
 
Old Mar 16, 2009 | 11:56 PM
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Ok, I wish they would make up their minds as to how they call these damn valves.

Found them in the EBahn... aside from that TSB.
Now if I could only find'em somewhere....
Thanks again HX
 
Attached Thumbnails Diesel-like sound-retentionvalves.jpg  
Old Mar 18, 2009 | 01:06 AM
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Besides the fact that I cannot find the retention valves to buy them just in case, how come all the parts stores neither list a cam chain, nor a chain tensioner for a 1995 V6, 2.8L?

Is there anyone in here who did have or has a 1995 and pulled apart the engine that could really confirm/infirm this model has or has not a chain tensioner (actually two, for both camshafts)?
In the Ebahn's exploded views I can see a chain, but there's no tensioner that I can observe. Why would be no mentioning of the tensioner, if the 1995 AFC indeed has one?
 

Last edited by chefro; Mar 18, 2009 at 01:11 AM.
Old Mar 18, 2009 | 02:46 AM
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Just a thought. Before you get deep into changing parts in the engine take a look at a real basic. If you buy your fuel at the same station all of the time try a few tanks at a different place. Not all high octanes are created equal. Throw in a fuel system cleaner at your next fill up. Chevron synthetic with Techron is on the higher priced side but is well worth it. Dieseling (pinging) is quite common if your octane is not high enough. Again.....just a thought.
 



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