If you cut the balance shaft belt the front engine shaft will not spin, but the oil pump driven gear shaft will. As it is turned by the oil pump itself.
This will STILL result in an "out of phase" vibration akin to OMG, my shits going to blow up.
You need to get the removal kit, or atleast the oil pump b/s stub. That's all you really need, as you can leave the front shaft in to prevent removing/installing new bearings. (Which is a BIG pita) The oil pump side b/s bearings don't have a feeder groove like the front side ones. That's why you need to block them, or oil will just blast out of the holes with no resistance.
I'm getting some shitty vibe/harmonics when the engines cold that sounds like its coming from the same place. I don't have b/s and I installed a new water pump AND idler pulleys for the timing belt. (I did use a 1G crank pulley since my 2g walked apart) But originally had no such problems.
It developed after 2-3 weeks of driving the vehicle.
I let it hit op temp (2-5 min idle) and it fine. It won't make any noise at idle.
No clue, my bottom end has 161,000+ on it.
(to my knowledge) So I'm running stock boost to avoid the obvious. No tap, knock, or smoke. (could be rebuild gremlins) The rest of the car was kept in really good shape, so it could have been overhauled. I'm thinking its the water pump tho. (I'm not running a thermo, due to overheat in the beginning, now its fine, I'm just lazy and haven't put it back in.) But the style of the pump angered me. It looked like a 1g brake rotor style pump, instead of the 2g OEM open face bent fan style. I asked 50 times "are you sure? if its wrong I will come back and shoot you". But it still never sat with me. Sounds like pump howl but with more vibe. I'm basically online with the same problem. If I get anywhere I'll post it. Could be anything tho, its been "my car" since July... someone else's for 10 years.
I think the knock sensor is picking up on it tho, as it gets sluggish when its doing it. Then pulls 200% better when its warm. (I used perfectly cleaned & tested, or brand new parts when I rebuilt the top end. To avoid trouble shooting shitty parts.)
I've already changed out my "break in new parts oil & filter" so all my assembly lube & such is flushed already...
Keep going down the list...