Timing belt question and noise

[ahlem]

I have an odd rubbing grinding noise on the front of the motor.
I removed the cap and rotor and there is fine shredded rubber dust under there.
Apparently something is causing the timing belt to run forward on the innards. I will dissect further but wanted to know if anyone had seen this before. I suspect the idler pulley but it was replaced about 15,000 miles ago.
Any ideas?

[jeffnhiscars]

Tensioners are known to go bad prematurely

[ahlem]

I pulled the upper timing belt cover and can see that the tensioner pulley/wheel is obviously bad. There are wear marks inside the timing cover and the little clip that holds the cover for the CPS wire has been polished to the point that the little ears are just about gone. I'm replacing the timing belt and the tensioner.

[jeffnhiscars]

At a minimum add the tensioner spring. I do all belts and hoses w every TB and unless you know the water pump as changed last time they did they belt, may as well,do it too

[ahlem]

Water pump is also 15,000 miles old. I did the project myself last time as well.
I will get a Continental timing belt and tensioner kit on Tuesday. I don't know if the tensioner spring is included.

[jeffnhiscars]

Water pump is also 15,000 miles old. I did the project myself last time as well.
I will get a Continental timing belt and tensioner kit on Tuesday. I don't know if the tensioner spring is included.

It's not but for the $2 it costs and the job it does....etc

[nando]

the tensioner spring does not wear out, unless it's broken or rusty there is no reason to replace it. also, it only sets the belt tension when you are installing the tensioner - once you have it bolted down, it's functionally useless.

[Cabriolet]

the tensioner spring does not wear out, unless it's broken or rusty there is no reason to replace it.

I have about 25 used timing belt tension springs at home. yes they do wear out. not a lot but they do lose about 20% of the stiffness from heat, creep, vibration. they are 15-20 years old and for the $1.5 price, it's worth changing them.

[jeffnhiscars]

the tensioner spring does not wear out, unless it's broken or rusty there is no reason to replace it. also, it only sets the belt tension when you are installing the tensioner - once you have it bolted down, it's functionally useless.

Keep in mind that they do stay under tension once it's all locked down so it's reasonable to conclude after 4-5 years they may not be "as new".

As cabriolet says, it's really not a corner worth cutting

[ahlem]

Everything is back together and running smoothly. The rivet portion at the tensioner pulley shaft to the stamped bracket was loose and allowed the tensioner pulley to wobble and hit the inside of the timing cover and the belt to run forward and start to shred itself.

[nando]

Keep in mind that they do stay under tension once it's all locked down so it's reasonable to conclude after 4-5 years they may not be "as new".

As cabriolet says, it's really not a corner worth cutting

spring steel doesn't "wear out". Maybe over tens of millions of cycles - that's what makes steel great for making springs out of. Just sitting there compressed, isn't going to make any difference.