Stock long block - never touched the knock sensor - trying to track down a snapping sound coming from engine under boost (>8 psi). Started a month ago and have tested several things: coil and ign module, plugs replaced, fuel pressure is good (under boost), methanol spray is working, no leaks in tubing-intake-throttle, MAP voltage agrees with boost pressure readings. I haven't checked the injectors - 42# from TT, 6 years old.
The snapping sounds like detonation but i don't see KR on scan master. I tried testing knock sensor but get no KR unless I directly tap on the knock sensor with large screw driver (in park, RPM's 1500-2000, TT Alky chip). Hard, continuous tapping on the engine block or intake manifold near knock sensor will not produce KR with same conditions. Searching several posts about knock sensor tests, and people tend to think that tapping engine block in the back drivers side should show KR on scan tool if idle RPM are high enough for chip to respond.
Is my knock sensor worn out or not torqued properly? I'm still trying to find out the source of the snapping sound (detonation?) - haven't found a way to be under the hood during boost.
The snapping sounds like detonation but i don't see KR on scan master. I tried testing knock sensor but get no KR unless I directly tap on the knock sensor with large screw driver (in park, RPM's 1500-2000, TT Alky chip). Hard, continuous tapping on the engine block or intake manifold near knock sensor will not produce KR with same conditions. Searching several posts about knock sensor tests, and people tend to think that tapping engine block in the back drivers side should show KR on scan tool if idle RPM are high enough for chip to respond.
Is my knock sensor worn out or not torqued properly? I'm still trying to find out the source of the snapping sound (detonation?) - haven't found a way to be under the hood during boost.