It seems like I have always had a knock retard problem with my 2000 A4
I have had the A/F and spark set right on the money I have even tried
new KR sensors and it still KRs. Several people have told me that it may
not be detonation causing the KR but a mechanical problem. How can
you tell the difference between real knock and false knock and what
types of mechanical problems are the promary cause of false knock ?

Thanks >>>>> INTHERED

 

Welp, there are a number of things that can cause false knock. One is the Air Conditioner clutch, two is the Serp belt idler. How do you tell? welp when do you get the KR. Do you have any Tuner SW? to monitor KR conditions, or do you just hear it. Could also be Carbon build up. do you granny it around or do a lot of heavy slow traffic driving?

The best thing to do is to run some scan SW. Just because A/F ratio is good and timing is no guarantee you won't get KR. Could also be fuel.

What mods are you running?

If you are running scan SW what RPMs is it in open loop or closed loop. What are the intake temps and Kps. Could be a whole bunch of stuff.

What is the KR count in the scan SW. If you are using it.

 

add to the list Aftermarket valvetrain, Exhaust striking the frame somewhere.

Phil

 

The KR seems ok on the dyno doing 3rd gear WOT runs but
when the car goes out on the street it is KR'ing 9 to 10 degrees
when it shifts at WOT which is not where you would normally
expect to see KR. The car has 30000 miles but the axles, trans,
rear, and TC are all new. The engine has the stock rockerarms
but with the CompCams 54100 rpm kit.

 

WOT, Open loop, soooo that eliminates the Air cond. What RPM is it shifting at? I don't think it is carbon or plugs? Could be plugs, but that would be a reach.

Does not do it on the dyno? But it does on the street? What scan tool are you using to monitor the KR? It could be the valve train, but then I would expect to see it on the dyno also. Other than KR the only things that would pull timing are rev limit, and TQ management (shifting).

You say stock rockers? what about valve springs?

 

Ran into a problem on my 99 A4 doing something like that and I have determined I have a bad exhaust manifold that is rattling like a big dog. I get KR on shifts and throttle transitions. I used my HP tuners and locked the advance at 10 degrees and I could still generate KR of up to 8 degrees, I also put 100 octance unleaded in and on a 40 degree day it would show KR. I was even able to get KR on a free rev in the garage when I could hear the exhaust rattling. I'd check your manifolds out as I believe 2K and 99's have the same double wall stainless header as opposed to the cast iron manifolds on later cars. Just my 2 cents, YMMV. Jeff

 

I have the CompCams 54100 RPM kit with the stock rockerarms.
The RPM kit consists of 26918 springs, Titanium retainers and
moly pushrods. The only other mods that may be relavent is
that I have a Corsa pace car exhaust with their x-pipe and the
GM pre-cats have been gutted. I will check my exhaust manifolds
for a rattle there too.

Thanks for the input >>>>> INTHERED

 

The reason I jumped on this is I have a mild KR condition under WOT (Open loop only) I can accel as hard as I wish in closed loop and she is fine and I only get it at 4550 RPM and she is pulling 4 to 6 degrees, not a lot. I know mine is due to mods and needs a tune. Being I don't get into WOT everyday I am waiting for spring as I have a bunch of work to do on her and I also know she is on the very edge of lean. Being it is a 98 A4 and they are known to be fussy in the KR space. Usually around the MAF area.
INTHERED,
May be a MAF issue here as well now that I think about it. This car was tuned, but just may need to go a bit more to the rich side. By the way what is your coolant temp when getting your KRs.