Searched endlessly with some leads followed but so far no resolution. Car is an 03 Evo with ~90k on the odometer. Mods are a set of Tein Flex's and vishnu cam gears set to zero.

About 3k miles ago, I had the timing and balancer belts changed and vishnu cam gears installed by a reputable local shop. I was in Germany on business while the work was done and didn't have the chance to drive the car until a few days later. Immediately upon startup I noticed a slight vibration coming from the motor... even at idle. It mostly transmitted itself through the steering wheel and gas pedal. Moving up into the rpm range, the vibration increased in frequency but not in amplitude. In other words, the vibration gets louder without shaking the car more. The local shop I worked with was more than willing to take it back in and have another look. Initially I thought that maybe the balancer shafts weren't lined up correctly. The guys pulled the whole thing apart and verified that all was lined up correctly. They refused to charge me for the 2 hour fire drill. Great guys.

In the course of the past 3,000 miles, the vibration has gotten slightly less severe, but above 4,000 rpm it's excessively loud. Hell, between the vibration and my trasfer case whine it's amost imposible to have a conversation in the car. There is no loss of power, or gas mileage.

Visual assessment of the gears and belt last night yielded nothing.

Any ideas would be greatly appreciated.

Thanks,
Fitz

 

more than likely, they didnt time the oil pump side balance shaft
if not timed properly, it will cause alot of vibration.

 

Sounds like the balance shaft is 180 degrees out. The timing marks will line up but it can be 180 off. If this is the case, you would need to take the timing cover back off and remove the balance belt and rotate the balance shaft one whole turn. They should fix it for free.

If you take the cover off yourself, you can be sure if its out of time by lining up the timing marks and then removing a bolt in the back of the block and sticking a screwdriver in it. If the screwdriver will barely go in, its out of time. If it goes far in, its in time.

 

when turning the balance shaft pulley(oil pump side), if turning by hand it will want to turn
to three different spots. You have to turn it until it wants to stop pointing around the
timing mark area.(oil pump housing)