I just got a '92 Civic SI with a D16Z6 and within the first week it started knocking, this turned out to be the crank pulley wobbling. The previous owner installed a underdrive pulley and aparently removed the washer from the bolt causing the bolt to bottom out. The bolt broke when I removed it but I I got it all out (after several hours)and luckily the threads in the crank were ok so I got a new underdrive pulley like what was on it and a new bolt and washer but the new pulley wobbles a little, not enough to knock but just a little at idle. Is it possible that the old pulley damaged the timing gear and guides? Should I replace them as well?

 

Your best bet is to get a OEM pulley. IMO under drive pulleys are not worth it and you take a risk of ****ing your **** up. Get another bolt also with the washer

 

Get rid of the underdrive pulley they are crap anyway, go oem on the the pulley. new bolt, washer, and pulley you will be right on and good to go

 

most aftermarket pullys are solid and do not have the rubber gromets inbetween them and all the vibration goes straight to your oil pump

 

there have been many threads about the hazards of running non-dampened crank pulleys and where they substantial risks or not:

i searched underdrive crank pulley and turned up 90 threads most of which talking about the pro/cons of them.

as all they others have stated on a street car the advantages aren't worth it IMO.