Audi S6, pinging/detonation

[KTM-Mike]

/popdem.

I see your point Popdemonic. "98 oct." is E5 in my country I think and the temperature
was +-0 celsius degree when I was driving and still can hear the noise...
this is weird...98 RON is the "finest" fuel available for a descent money here.
I want the car functional with street-fuel thats why I want to fix the
problem...

/newsh

I've had the timing almost down to 0 degrees and very "fat" on the fuel and
still hear the knock sound.
I hear det. at 2000-2500 rpm over 1 bar atmos.
And det. 2500-3000 over 1,3-1,4 bar atmos.
This was at +-0 degrees celsius.

When I drive above 3000 rpm all is fine with or without boost...

Maybe I hear ghost in my engine

I very appreciated your help guys!

/M

[driftin jo]

Maybe your catalytic converters have broken up and are blocking your exhaust

[KTM-Mike]

/driftin joe

But wouldn't the pinging get even worse at high rpm/boost
with bad cat's conv. if that was the problem ??

/M

[Andrew Conway]

KTM-Mike

I have the same problem too on my RS2. Low rev's, medium throttle, heavy load. Once the car climbs the rev range a little and you get medium to light load on the engine (before boost starts) the pinking clears.

I haven't looked into it as yet because im not running the car (and its to cold to be stood on the drive) but once I can get into a garage with it im going to have a look into it.

One thing I have thought about is chain slap on the cam chain? I was going to chain that for a new chain to see if that was the issue. Are you able to plug into a diagnostic to see if your getting any error codes?

Thanks

Andrew

[KTM-Mike]

/Andrew Conway

That sounds like the same problem. My engine is abruptly silent just over 3k rpm.
I have checked the diagnostic and don't
get any faults, will check again...

I've built a simple circuit to test the injectors tomorrow, just to rule out those.

How many miles on your engine Andrew??

/Mike

[UrS4boy]

20VT AAN, ABY and ADU output tests

/ I've built a simple circuit to test the injectors tomorrow, just to rule out those.

The OE Motronic ECU has a function that tests the connection between the ECU and the injectors, WGFV, etc. Involves a paper clip and the white and black K and L plugs in the fuse and relay panel:

Try this:

http://www.sjmautotechnik.com/trouble_shooting/ecuf20v.html#outs4

As demonstrated here:

https://www.youtube.com/watch?v=SNwqbyQZzfY

[Andrew Conway]

Hi Mike

Mine has 112,000 miles on the clock.

She starts first turn of the key and idles perfectly, there is no hesitation or mis-fire on boost, its just that certain point in the rev range when you can here pinking

Please keep us informed of your findings.

Thanks

Andrew

[KTM-Mike]

/UrS4boy

Ah thanks, didn't know about that diagnostic test

I'm going to flowtest injectors with different frequency and dutycycle
to simulate real-world. Fill up a jar and measure the weight and see the
differences between injectors. A bit overkill maybe...

Someone know the threads from feed fuelline to fuelrail?

/M

[UrS4boy]

Someone know the threads from feed fuelline to fuelrail?
/M

The fuel filter adapter has the same threads as the fuel line.

But more importantly, for safety sake, there are companies that do injector testing, cleaning and refurbishment for a living and can "blue print" your injectors so they flow at least their rated flow at 3Bar (std. test pressure) and evenly across all (5) injectors.

Photo is from this: Making a Fuel Pump Testing kit

[KTM-Mike]

The injectors seems ok.

Flowed 266-267g/min , +-1%
between injectors.

/M

[mike74]

Have you tried running it with the lambda unplugged to see if its any better/worse?

[KTM-Mike]

/Mike74

Nope...will try to unhook it.

I thought the ECU only "looked" at lambda-value at idle ??

/M

[HMS-S6]

No. Part throttle too.

[domas]

how did you test the lambda? seems very lambda related.

[KTM-Mike]

/domas

I haven't tested lambda with stock ECU yet.
Will test tomorrow with an old Techedge WBand I have lying somewhere...

Did use a wideband together with the other ECU (MaxxECU).
Tuned it to different lambda-outputs, both lean and fat with no changes.

But same knock sound on both ECU...

/M