got a question about my harmonic balancer. Could having a small chip taken out of the edge of the outer pulley, affect the balance, and thus cause vibrations? The chip is about 3mm deep and about 20mm across. Looks like the pulley just knocked into something and chipped a piece off (it's a jdm h22 I got used).

Anyway, I looked at the balancer while the car was running (at idle). There was some slight, but noticeable, oscillation to it, and that was only at idle. Is this normal, even on a perfect pulley? Does anyone think a chip this small could cause undue vibrations at higher rpm. I ask, because it seems that at low rpms, there is a little more vibration than normal.

thanks

 

Its the crank pulley and yeah I would change it out.

 

I highly highly doubt this vibration is felt due to the chip taken out of your crank pulley(also your harmonic balancer). 3mmx20mm is a very very small amount of material you are talking about, the harmonics of your engine is vibration of certain frequencies relative to its mass, and beleive me, your engine is not harmonicly balanced within close enough specifications where a small nick in the crank pulley would cause it to vibrate anymore than any other prelude. It is much more possible that you got this motor that some has worked on previously and has tampered with the balance shafts, or disabled them. That would cause an increase in power and acceleration due to the loss of rotating mass, and that would be my guess why your engine vibrates more than a regular one should you think, and also even if it your harmonic balancer was not tuned properly, it would not cause the engine to vibrate at idle, it would be at much higher rpm that the crank would vibrate.

 

thanks for the reply.

I know the balancer shafts are definitely not removed, since I saw them when I serviced the engine (timing\bal. belts, wp). Plus it's no where near that kind of vibration . Plus there isn't any engine vibration at idle. I was actually just looking at the pulley spin at idle, and could see a little oscillation in it. The slight vibration I'm talking about happen from like high 2k rpms, to almost 4k, after that it's nice and smooth.....

 

well it wouldnt be the harmonic balancer if the vibration disappears at 4k, the vibration would only increase, possibly just a misfire that causes the engine to vibrate? sometimes its hard to tell if your exhaust is quite and you are at higher rpm, you might try getting a new cap & rotor, and if you are running cold plugs, you might want to try switching back to a slightly hotter plug and see if that changes anything, gl