When he looks at it, you might have him check the EGR valve.

I had the same problem (from nearly new) with my 94. We finally found the EGR ports (in engine and EGR valve) needed a good 'reaming.' I'm gonna try out something other than premium fuel, now.

Looking at octane, I came across an interesting article. Many engines have ping detection. If you run too low an octane fuel, they'll retard the timing. (This results in lower MPG, more carbon & lower performance.)

That is good news! I hope they can solve the problem.

They're not quite ready for prime time. A guy rode with me and it knocked a tad but not bad, it was cool and damp!
He tried to pass it off as a heat shield but I blew him outta the water when I asked, why then does it not do this when motor is cold?
He returned a "nobody's home" look on his face.

I have an appointment in Wexford June 3 at another dealer that IS up and running.  We'll see. If I get more shit from this dealer than that's it.  This thing is outta here.
If I had to guess, I'd say TPS as the spark knock is contingent on 1.  fully warm, closed loop   2.  Position of the gas pedal; only a certain position of pedal (and TPS) as well as RPM makes it knock.  Floor it, no knock.  Keep RPM under 2500 or so, no knock.  Cold engine, no knock.

I know the TPS has to tell the PCM the 1.  rate of opening of the throttle plate and 2.  the actual position its at.  My contention is the TSP is still within spec and responds to the 5v reference voltage but I think its "stuck" at the far end of the scale telling the PCM that I am at or near WOT and thus the PCM will 1.  provide a LOT more spark advance.......2.  Lengthen the injector pulse width to throw more fuel in order to provide more power.  That and along with 1.  a slight blimp in the throttle cuts out the AC compressor (it does this by design but only when the throttle blade passes 54 degrees of travel within a specificed time frame....ie a ssssssloooooooow push down to WOT won't kill the AC) and 2.  a slight off idle and part throttle hesitation .

Well that's my theory anyway.  What I am solidly convinced of is most Techs, ASE certified or not, rely too goddamn much on the "scanner" to do the thinking for them.  If there ain't no code, then gee.......I can't find the problem.  Meanwhile, rome is burning and my valves are a knocking.  Duh!

What I am learning is that Suzuki has a way to go in customer service before it can really hang with the big dogs.

I mentioned this to my neighbor. His GM was having the same knocking problem you mention. His mechanic thought it was piston slap. They proved it was pinging by using some octane booster. (They bumped octane to about 120, he said, and the knock went away.)

That stuff is $3-4 a can, so might be a good place to start.

I don't know about 'Zuki, but if premium gas will stop the knock, GM wouldn't fix it. (That was their first "solution"... run a $47 can of carb cleaner through the engine & told him to run 3 tanks of premium.

That's an expensive "solution"!  

That's an expensive "solution"!  

Agreed. They charged him $35 for a 'warranty' service call & $12 for a $3 bottle of injection cleaner.

I've dumped enough cleaners, etc into my tank that I think its running on chemical compounds instead of gas!

I have June 3 set aside for a trip to a dealer in Wexfor.

Just got back from a trip up I79 to grove city and back and it was a knocking big time.  FIlled up with Citgo gas 87 octane and its sipping that now but still knocking.

But you know, I don't give a f**** any more! actually, I hope it throws a code or worse, blows a piston.  At least then it will be so broke dick that no dealer, unless they're smoking crack, will be able to cop out and say, "I can't hear the problem"!