D15b7 with a D16z6 mini-me swap( plus all the accompanying intakes and shitty exhaust that you find on a 1992 civic hatchback)

Been daily driving it for about 6 months since installing the Z6 head. About 3 months ago, I notice a noise from under the hood when accelerating. It sounding kinda like whistling, but I know it isn't possible air making that noise. The noise has gotten marginally worse is the last 3 months since its first appearance. I hear this noise only when I am giving it a lot of throttle (70%-100%) but still in about the 2000- 3800rpm range(at which point the exhaust gets too loud and I can't hear anything else anymore)

today after a drive on a hot day, i nearly mistook the noise for driving over the dead leaves on the road. The noise of crunching lots of dead leaves is the best way I can describe this. But it does not sound loud or violent enough to be any issue with the block (ie, rod knock))


I've loosened and re-tentioned every belt on my car, even took the timing belt off and put it back on. Not sure what else could be my problem but I'm almost positive the problem is in the area of my engine with the belt pulleys.

what confuses me the most is how it is only when it only happens during certian throttle conditions. Could this be a belt slipping under the torque change? In which case, how?

I know its hard to diagnose a sound on a forum, but If anyone has any ideas, much appreciated. I am stumped right now.

 

when a v belt or serpentine belt gets old, they dry out and sound crunchy. Im not saying thats your problem, but the old belts on mine sounded "off" at idle, I changed them with new and no more odd noises. Pop the belts off one at a time and spin the pulley (power steerin/alternator/AC) and see if one of them feels crunchy. It could be a bearing going out.