ok 90 Toyota sr5 with a 92 3vze and a340h 170000 miles .under load there's a sound that's like miss adjusted valves ,metallic almost a belt squeal . only under load .and I have a knock sensor code (52 I believe ) replaced the pigtail (which someone had wrapped with foil) still there, cleared it and did the knock sensor re-location to engine hanger ,still set the code .replaced the hydraulic tensioner and idler pulleys .still that noise and the code .any suggestions before I open the motor up and check everything ? compression is between 175-185 across the board, valve shim to lobe is .007-.013 across the board so everything seems in spec.maybe pcv valve or ecm ?the wiring has been redone and I figure there may be problems . idk im at a loss