loud crunching sound under passenger floor?

jetuomi

Founding Member
Jan 30, 2002
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Toronto, ON
ever since I got the new motor in, there has been a loud crunching sound at low rpm's, under the passenger side only... you can't feel it as a driver but when I switched to let my friend drive boy was it loud, and it shook the seat a bit when nobody is sitting in it...

what could this be, the motor sounds quiet inside the bay, but next time it happens I'm going to pop the hood and listen closer.. it doesn't happen all the time, and, yet, it happens at between 120-170 on the engine temps, AND/OR it happens when the car goes into closed loop at idle.. (I'm tempted to make my idle OL all the time now @ 15:1 or something)..

now that I think about it, the car at idle increases the pulsewidth from 3-7 and it almost stalls and as that pulse width widens (getting rich) the car crunchs more and more.. I give it a rev and the crunch goes away..

strange no??