Originally Posted by
Omotesando
Well first of all if there is no ascertainable, seat of the pants power-cut, that is a good indication that it is not engine pinging. I disagree though that you haven't experienced Knock Sensors that do not do their job properly. How do you know, if you haven't put the car on the Dyno? In your and others case, the suspected pinging/detonation is happening at low revs. There is absolutely no way that knock sensors do not detect low-mid rpm range knocking 100% accurately. Only at about say 4000-5000rpm or above do they become a bit confused by other noise but even then, these days the redesigned filter system makes them reliable even in the higher rpms. When I was dyno tuning my performane car before, the stock Knock sensor, my PowerFC computer read-out, also on the Dyno - all correlated. So, I would recommend that you should ask Honda to pay for a Dyno session just to isolate this problem.
Also contrary to what you said, Auto gearboxes get better when warmer. The lower Viscosity of oil or in Auto Fluid's case, is because at low temperature they can flow enough to protect the moving metallic parts. At lower temps, the thinner fluid makes it susceptible for metal to contact metal with the thin film, thus creating 'clunking' noises. At normal warmer temp, the high oil viscosity is operating in its normal range, with a thicker film that protects metal from metal as it should, whereas with cold start up the emphasis is on as fast a flow of oil film as possible. Therefore it is impossible that in an auto gearbox it will make more noise when warmer. You're arguing based on your understanding of thicker viscosity at higher temp relative to colder temp, but in reality the warmer performance is the perfect viscosity at normal operating range. The only scenario I can think of when higher viscosity gearbox oil doesn't work too well in a gearbox is when it is too thick in a manual gearbox, where the synchros makes it hard to compress the oil film and change into another gear.
I honestly think you should put it on a dyno to make sure if it is even pinging or not, as it is fairly conclusive plus there are manual microphone equipment (not knock sensor) that can confirm it further. Its only around $100-120 and on dyno days its barely $50-70! :D