Mongo

I'm still trying to work out some kinks so far after the rebuild. Today the car passed smog with flying colors. Unfortunately, we've discovered there is a vibration at 4,000 RPM. The vibration is apparent through the shifter when the clutch is both engaged and disengaged (stepping on the clutch pedal). In the garage we took it up to 4,000 and heard a strange shrieking noise coming from the exhaust and a buzzing noise coming from the top of the cam tower of the motor. We are both stumped here. Anyone want to shed light on helping us diagnose this issue?

So far motor has about 50 miles on it and about 10-12 hours running time included.

Techno Duck

Are you sure you installed the balance shaft sprockets correctly? Also are you sure they are lined up right?

Mongo

I'm going to pull the covers today and have a look in there. The balance shaft sprockets are correctly installed, but maybe they lost alignment as I was tensioning the belt.

I looked at some previous threads and people have complained about vibrations coming from a bad torque tube. Dunno if at 4000 rpm and a little over, that vibration would be related to it. On to checking the balance shafts now I guess....

cjeckert

I remember reading if its heavy vibration around 4k its the balance out of alignment. Hope you figure it out, nice cat btw i want to get one that looks that nice some day.

sammy-r

That's exactly what happened to my car (heavy vibration at 4k) after replacing the belt. One of the balance shaft sprockets was installed 180 degrees out.

Mongo

I'll take a look at the belt then. Oh and BTW, if someone is questioning the clutch, it's a brand new spring center. I'm hoping the worse case scenario isn't torque tube bearings or a damaged shaft since the engine removal. I seem to be getting myself paranoid thinking about that. Time to pull the covers and open a beer then!

Mongo

Okay all fixed! That is the easiest way to freak yourself out....setting your lower balance shaft sprocket 180 degrees off

hosrom_951

You got lucky, i broke the p/s mount, cracked the fuel rail, broke off the compressor mount and shook almost any bolt loose.......

Mike C.

I did the same thing once. Glad it wasn't anything serious.