Spun bearing???

[tropicoz]

R6 motor, if it spun a bearing will it knock continuously as it runs, or will it come and go with revs? Looking at a motor that knocks at idle, then quiets down for a second or two, then knocks again in repetition. Seems to keep quiet when revs stay higher.

[myzx6]

Usually spun bearings knock consistently with engine speed but not always, some will only knock at idle. From what you describe its most likely a spun bearing but you never know till you open the engine up.

[tropicoz]

Here's a video https://youtu.be/SVa7xlIDIZw

[Eric Baker]

That definitely doesn't sound like a rod bearing. It sounds like something's loose, possibly in the transmission area.

Typically this is what rod knock will sound like, though this is a car.

[csmutty]

I agree with Eric. Sounds like something in the clutch or tranny.

[Danz19899]

Agreed doesn't sound bottom end to me. Does sound like something bad inside the clutch or tranny. Does pulling the clutch lever or putting it into gear affect it at all?

[tropicoz]

I'll run it through the gears today to see if it continues making the noise in gear. Glad to hear it might not be the bottom end, but it's still a major repair if it's the gearbox, no? Any of you done a tranny rebuild (and I don't mean you Smutty, with your cross dressing and all!)?

[number9]

They can be a little annoying to use but have you tried an automotive stethoscope? You should be able to get one at Sears or the like. Or you could do the ghettofabulous method which is use a screwdriver (or something solid) by putting one end on the case and one end in your rear.. erm.. ear.