Whirr sound-Balance shaft belt

[FabricGATOR]

I ask of you fine people .....

I recently changed the waterpump, timming and balance shaft belts. I didnt change the rollers, idlers, seals etc. I set belt tension (por instincto)
as per some advice from Vertex. Waterpump did the trick, but I now had a funny whirring sound. From FR Wilk I remember the story of a previous mechanic getting some pully/rollers backwards that gave him similar symptoms leading to eventual timming belt (premature) breakage and all the other damage associated with a high speed failure. (OOPS!) He also described how the belt wore a slot through the plastic covers.

(More pre info): Waterpump siezed (almost) and wore the back of timming belt therefore change it also although the apparent wear (dry rot, checking, crazing, etc) was not present. And for good measure also the balance shaft belt. Vertex sold me the updated wide balance belt.

Day Two: I removed the Power steering and Alternator belt... still had the sound which I was not able to change by manipulating the plastic covers nor pinpoint using a stethascope.I removed the upper and lower covers and checked the belt tension with a tension tool (kriket)..... I was pretty close with both.... Vertex taught me well. I did a short engine run with the balance shaft belt removed and the whirr went away -it sounded like it should. Inspected everything.... no visible wear, chaffing, apparant bearing noise or feel.... Being just as new as new gets I inverted the balance belt, kriket tensioned and tryed a start. The sound was less pronounced. Reassembled and drove on. It seems that over time this is getting either louder or I am becoming more aware of it.

Did I need to spend the dollars on the new rollers and idlers?? Is this where I went wrong? Could the rubber belt possible wear the steel pulley's? Is that whirring noise possibly the sound of a healthy Porsche? Being that I dont think that Balance shaft belt failure could be that catostrophic (unless it kills my timming belt when it goes) I figure that I will continue to run it until it reveals itself -OR- If you enthusiasts have some suggestions or advice......Am I just being unrealistic in my quest for perfection? It is just another used car!

Kurt

[930guy]

For the few extra dollars I would have done seals and rollers and then would not have to worry about anything up front for a quite while. Spin each roller/tensioner and see if they sound dry/noisey/rough-replace as necessary. Make sure you have the ecentric rotated the proper way(clockwise/counter clockwise) I also see frequently people mix up the timing tensioner(early style) with the balance shaft tensioner.

[xveganxcowboyx]

I have the same problem and have been thinking the same thing, but it worries me. Not to mention annoys me. If it's not a big deal I won't worry about it, but I haven't done any belts on the car yet so I might do them and try to solve this problem. What's the story on this noise and the best way to solve it?

[neo the hacker]

I did the head on mine abd replaced the belts, when i started it up it had that noise, so i stripped it back down and slackened the b/belt off, but it still did it but not as much, driven it for a few days then the car started to vibrate at about 2-3tho revs, stripped it down again and the b/belt had jumped about 5 teeth or so, so now i just put up with the noise. their was no noise from the rollers and everything was ok?

[FabricGATOR]

Thank you for your input, I apologise for not being able to reply until now..... I got eyewalled by the hurricane Francis last week and it killed the power, cable, and telephone for a while. The car sustained no damage.

I seem to be confident with the belt change and inspection. I beleive that the noise is starting to settle in -OR- I'm just getting used to it. I agree, I wish I could have resealed the front and re-rollered everything....... I didnt see any evidence of that being necessary (no leaks, no apparent wear, good bearings, and the old balance belt looked fine-low mileage) Possibly the previous owner had "all the right stuff" done.... and hopefully by someone who can seal more then a ziploc baggie.

PAP-auto parts. I am going to install my new "studio foam" hood liner (80 Bux)(delivered) Maybe thats the part I have been missing! Might just hush that whirrr to the point that I just cant hear it!

I'll try to keep ya'll updated on my success in making at least that noise go away.
Kurt

[FabricGATOR]

The hood foam kit didn't do much........hehe

[blmcomputers]

Hi I have the exact problem with my 944. I have rebuilt the balance shafts, new rollers & tensioners, new belt, but the sound is still there!!!

Did you identify the problem with yours?

Any help you can give would be greatly received.

Cheers