Originally Posted by
Mike W
We never build any motors with balance shafts. Without balance shafts the 4G63 vibrates like any other 4 cylinder motor in the world without balance shafts. With balance shafts in out of phase, they make this horrible noise and vibration past 4k rpm.
If your motor has no balance shafts and is vibrating that bad then it is not a Buschur motor. It would be some backyard motor.
The notch on the oil pump sprocket can line up and the balance shaft can be in phase, then the next rotation it lines up and it is out of phase. Out, in, out, in... whoever does it needs to know their 4G63 motors well. There is more to it than lining up the marks. With an average Joe mechanic working on it there is a 50/50 chance of it being correct. You: "Dude, I think you forked up the balance shafts, it vibrates horrible now" Average Joe Mechanic: "No way brah, I lined up all the marks, look! They are all lined up" But it is still wrong and vibrating. You wouldnt be the first 4G63 owner to have that conversation and wont be the last.
A short block from anyone does not come with or with out balance shafts. That is up to whoever takes the motor from a short block to a full running motor to do or not do. And to do or not do correctly.
Your oil filter would be trapping any metal shavings. You would see the early signs of impending doom by cutting open the oil filter and having a look inside.
Regardless of all the internet conjecturing, the first step from here is for someone that knows 4G63s to have a peak inside the lower timing cover area.
You bought it like this? Ouch.
Mike W