91 gsx....vibration at higher engine RPM causes bolts to come loose!

[jeff91gsx2pt0]

hey guys, as the name shows I ave a 91gsx.

as with many dsm I blew my timing belt ages ago and I had the head rebuilt and the motor put back together. Since then i feel like the engine vibrates a lot. Not like a vibration if it was missing but like almost like a one of those massagers that go BUUUZZZZZZZZZ.

its worse around 3-5k, on the highway at 60mph its fine, but at 80 there is a noticeable vibration.

I even have MAJOR issues with keeping bolts tight on this car. 5 times already the bolts to the half shaft bracket on the drive side have come loose. I have had the power steering and alternator loosen up on me as well.

I am just wondering what it can be, and how I can trouble shoot to figure it out.

edit:

i was just reading about the balancer shafts. I understand these could be out of alignment. Fixing these will fix the vibration, BUT i have heard of these being ticking time bombs. I have had enough issues with this car. Should I just remove them? Is there a how to or pictures any where with how I can take them out?

 

[snowborder714]

Balance Shaft Eliminator Kit Install

 

[Raph]

Sounds like the Oil pump balance shaft is out of phase

 

[jeff91gsx2pt0]

Sounds like the Oil pump balance shaft is out of phase

its best just to remove it?

how big of a job is this. I am a pretty decent amateur mechanic.

also, can it be possible that removing them can make it vibrate LESS, if they are off and making it vibrate worse?

 

[snowborder714]

You don't remove the oil pump shaft. Whenever the engine was timed, the oil pump was probably timed incorrectly. The way to make sure it's correct is to bring the timing mark on the sprocket to 12 o'clock. Release it and if it falls counter clockwise towards the timing mark, it is in phase. If it falls clockwise away from the mark, rotate it 360* and retry.