Engine Vibration Need Help Please
 

hello to all, im a2 month old 944 owner and have been happy with my car UNTIL my parts arrived from ebay and i changed my belt. the shop i brought it too is not a porsche specialist although they seem competent enough top work on european cars. (the local porsche dealership do not service the older models).

my belts were loose when we opened them, they could be pressed down and touch the surrounding guides and housing. i was relieved it didnt break to this point, ive been driving hard lately, and althouggh the shop does not have the factory tensioning tool, i feel anything is better than how i saw it, and hand adjusting it would suffice.

the belt is on, same with sprockets and rollers it came with, car starts and reves freely, except that my engine developed a high frequency vibration at all RPMs, most pronounced at 1700-2000. the vibration can be felt at the gear shifter, the steering wheel, the pedals, and causes the transmission to buzz at the mentioned rpm.

my instincts tell me to concentrate on the belt/sprocket area. i have gary husseys book and it says "its easy to stack the lower balncer shaft sprocket wrong" (did he mean face in as opposed to out?) should i consider putting back my old sprockets in?

any inputs greatly appreciated. thanks in advance. heeeeeeeeeeeeeeelp!

RE: Engine Vibration Need Help Please
 

They do not have the balance shafts aligned properly, which is causing your vibrations

RE: Engine Vibration Need Help Please
 

thanks porschedoc, i think youre right. i think they got the balancer shaft timing wrong but just didnt tell me anymore. when i got to the shop the morning after my initial post, the vibration was totally gone. they claim they loosened the belt (no factory tensioning tool, this shop) but i pressed my finger against the belts and it wasnt too far off from the tension when it was vibratintg.

i brought the car out and have driven it twice since, one time from the shop to my office. and this morning to the sierra madre twisties 1 hour southeast of manila. i now understand what the fuss is all about. this car grips and begs you to push harder and harder through the turns!

my question now: there is a nast whining sound in the belt area. i used a stethoscope when the cover was off and have localized it to the balancer belt (sound comes from all areas the belt has contact, with pulleys, with idler, with tensioner) could this be because of my balancer beltbeing 2mm wider than my old one? could this be because its on too tight thus the idler bearings are making noise? could it be because its on wrong?

im not as worried now, like i said, anything is better than how i found my old belts to be. you may have experienced this, your inputs much appreciated. thank you in advance!

RE: Engine Vibration Need Help Please
 

If the balance shaft belt is too tight, it will whine like crazy :)