Audi S6, pinging/detonation

[KTM-Mike]

Tested unhook lambdasensor. Made no difference.

/M

[KTM-Mike]

Tested unhook the hose to the wastegate.

Sound is completely gone.

Diaphragm seems to hold vaccum (top connection)

What else could be wrong with WG ? Spring broken/too weak ?

/M

[Pirvu Eugen]

Stupid question maibe...but the hoses to WGFV are connected correct?
The valve is working correct?

[UrS4boy]

N75 WGFV info

Stupid question maibe...but the hoses to WGFV are connected correct? The valve is working correct?

Good suggestion Pirvu. Here is the content of a post I did in the fall:

"Somebody on Audiworld was having boost problems. Their WGFV to wastegate hose was not attached to the wastegate, i.e. banjo bolt is gone. So I thought I better add some photos to the N75 post and help the guy.

More N75 WGFV info here: http://forums.quattroworld.com/s4s6/msgs/20987.phtml



and while I was doing that, I thought I might as well add these two:

[Pirvu Eugen]

Take care that the WGFV plug position regarding hose connections is different between AAN and 3B engine. 90 degrees.
I think you cannot mistake the connections...but....just to know.

[KTM-Mike]

/Pirvu
/Urs4boy

Not stupid question, all help is appreciated.
Yes I have checked hoses. It's ok.

I have tested to unhook the N75-valve (electrically, NOT the hoses)
which will give me 0,4-0,5 bar boost, and the sound is there.
The sound disappear only when completely remove hose from lower
WG connection.

This will rule out the N75 I think as the problem right????

/M

[Pirvu Eugen]

For reference!
This is 3B item and you can see that the connections are 180 degrees oposed'.
This is 283J.
Hope this helps!

[Pirvu Eugen]

/Pirvu
/Urs4boy

Not stupid question, all help is appreciated.
Yes I have checked hoses. It's ok.

I have tested to unhook the N75-valve (electrically, NOT the hoses)
which will give me 0,4-0,5 bar boost, and the sound is there.
The sound disappear only when completely remove hose from lower
WG connection.

This will rule out the N75 I think as the problem right????

/M

I am not an specialist... but this sound right...with electric connection out...the turbo to WG has to be open. The WGFV is closing that to keep the WG shut.

[Andrew Conway]

Hi KTM

Just read page three when found this on the web. http://www.s2-audi.co.uk/tech_articl...ronic/wgfv.htm

Hopefully this may help.

Thanks

Andrew

[newsh]

Tested unhook the hose to the wastegate.

Sound is completely gone.

Diaphragm seems to hold vaccum (top connection)

What else could be wrong with WG ? Spring broken/too weak ?

/M

Which sound is gone? Sound of leaking? Or sound of Pinging?


If pressure testing, there will be a small leak down the WG valve guide into the exhaust, it's normal.


Another thing to try. At the ECU, take off the vac/boost hose, cut 10 or 15mm of the rubber hose off, re-make the connection being sure the clamp is tight.

[newsh]

For reference!
This is 3B item and you can see that the connections are 180 degrees oposed'.
This is 283J.
Hope this helps!

The long leg always goes to the MAF hose.
The opposite one goes to the WG
The middle one goes to the face of the turbo.

[KTM-Mike]

Which sound is gone? Sound of leaking? Or sound of Pinging?


If pressure testing, there will be a small leak down the WG valve guide into the exhaust, it's normal.


Another thing to try. At the ECU, take off the vac/boost hose, cut 10 or 15mm of the rubber hose off, re-make the connection being sure the clamp is tight.

The PING-sound is gone when I remove hose from wastegate.

/M

[newsh]

Audi S6, pinging/detonation

So it's definitely not detonation then! Maybe the valve in the WG rattling.

When you drive it with the WG hose disconnected you will get way too much boost so if it was detonation it would be even worse.

[KTM-Mike]

So it's definitely not detonation then! Maybe the valve in the WG rattling.

When you drive it with the WG hose disconnected you will get way too much boost so if it was detonation it would be even worse.

Yes, that's my conclusion also. I'm gonna test remove N75 completely,
and just connect a single hose from compressor house to
lower port (the usual port) of wastegate. If its rattling then its probably NOT
N75-valve and something inside wastegate I think...

Really appreciated the inputs!

/M

[KTM-Mike]

Removed wastegate tonight.

I think there is too much play in WG that is causing the rattle...

How much play is acceptable ?

Is it repairable, bushings or whatever inside... ?

/M