Ok so a while back I replaced my 130k oem timing belt with a gates performance blue belt, The quality of the gates belt is awesome , its super stiff and thats where my problem lies...

so after the swap everything is lined up perfect I start it up, no noise whatsoever , the car warms up and bam timing belt noise Okay I figured since the engine expands with heat It probably got tight ,

So instead of ripping it back down I popped the cover in the engine block mount and loosened the tensioner bolt while it was hot then retorqued it to specs...all was great , very lil noise at idle and you couldnt hear it at all under a rev..

Skip to today , start it up and its great no noise , run out to my uncles machine shop to do some work for speedcorps , and at idle its whirring again the engine was warm , what the hell ?
with all the years at mitsu I have under my belt Ive never heard a stock belt do this and I can only attribute it to the fact that the belt is super strong/stiff ,

Though it doesnt make sense that the noise would go away and all of a sudden come back , it is definetly coming from the cam gear and belt contact on it , the gear is fine any ideas guys? or just live with it? I know its not uncommon for the blue belts to make noise I guess just ignore it huh?

 

is it a whining sound?

the only time a timing belt will make noise is when it is over tightened.

wheather its a fiber reinforced belt such as your gates racing one or OEM, when over tightened it makes noise.

not unless you have a worn tensioner bearing which is highly unlikely

 

Did you replace the water pump when you replaced the belt? You could have thrown a bearing with the tighter belt. I've been through a couple water pumps and each time I replace it, the whining in my engine goes away (noise at idle sounds similar to what you're describing). I've just got my fingers crossed that this one lasts longer...

 

Can be as well... but water pump damage is sort of a nearly a high pitched sound and producesn nearly a consistent noise, however I could be wrong! Its hard to diagnose stuff over the internet as you know youtube it.

Tighter belt does lead to gradual reduction of life on water pump, you could back of the tension a bit on tensioner pulley and ensure you have the right deflection on the timing beltnext time around.

 

the deflection is within specs 5mm-10mm which is what the 4g94 calls for , its definetly not the water pump , it'd make a high pitched squeal like metal on metal with a drop of water lubricating it..lol that and its not leaking through the weephole

what I dont get is its not consistant its every half revolution of the belt , I was thinkin maybe I got one with a slightly misformed/crooked tooth on the belt