belt noise and general restoration questions to the more experienced

If you see no holes in the muffler I wouldn't really worry too much about it. My Magnaflow can rusted from the outside in fwiw. 

Your serpentine belt appears to be a laterally grooved piece. The stock Toyota belt has the grooves running longitudinally. Older threads used to mention these aftermarket as a source of more noise. Never had the experience myself, but I use the stock type set up. If the pulleys are not a source of noise themselves, the rust on them is just a cosmetic issue.

With the belts removed, spin all of the pulleys by hand. You should not feel or hear any clatter. If so replace.

@murray

Thanks, I purchased a replacement from Napa before reading your reply but thankfully is longitudinally grooved. 👍 

@cspidy

Good info, thanks very much.

@haloruler64

Thanks, decided to rust treat and paint the old borla.

The idler pulley can make a reasonably loud gritty hum before it dies. Focus on what noise and from where. 80k for 18 years means it sits a bit. 

@ispy

Thanks for your reply!

Got something done over the weekend, valve cover painted & cured in high heat red & clear.

All,

Serpentine belt question:

Performed replacement and new Gates longitudinal belt was routed correctly on all pulleys.

Tensioner had been replaced recently and is in good shape.

Experiencing loud squealing from what would sound to be the alternator pulley after the new belt installation.

Assuming I did not have it tensioned correctly and it was too loose (?) have removed to re-install.

Curious if there is some other well known issue to you experienced lot other than incorrect tensioning.

Thanks for any input.

Bad bearing on the alternator pulley, give it a spin with your fingers. Should be smooth and quiet.

if it’s slipping it will sound like a chicken

Thanks, alt pulley spins smoothly when belt removed, which makes me think I somehow mangled the belt installation though it the routing is all correct

So it became apparent that there was too much play in the tensioner pulley and spring. 

Of course the smaller top flange nut on the tensioner assembly is seized on and rounded off, in line with all of the other bolts throughout the exhaust system.

It wouldn't be the same if that weren't the case and what's one more poke in the eye, anyway.

That nut sits on a stud that is up against the firewall, so damaging that stud thread would mean dropping the engine to replace it I'm afraid.

Once more into the breech with a nut splitter / chisel / torch.

I just got done fixing this issue.  Even though this is an older post I will reply.  I had a lot of noise in my accessory drive system when I bought my 20 year old 2000 Spyder.  I had a loud whine that went up and down with RPM - this turned out to be the alternator.  I made the mistake of buying a new aftermarket alternator and after a day of trying to get it to fit I ordered a refurbished Denzo unit from my Toyota dealer.  Perfect fit the first time.  Whine fixed.  I still had a grinding sound that was driving me crazy.  I purchased a replacement idler arm pulley from Advance (20 dollars) and a specialty socket from Amazon (10dollars) that is needed to remove the pulley nut.  Still had the noise but that pulley was old and need to be replaced.  I then replaced the metal grooved idler pulley (50 dollars from Toyota) that had a small amount of play.  Bingo!  It was whisper quiet after replacement.  I also bought a new water pump (112dollars from Toyota) due to the age of the car and the mileage (100k).  I figured whatever made everything else go bad was probably going to cause the water pump to fail.  If you want to see if your noise is caused by something belt driven vs the engine you can remove the serpentine belt and run the engine for 20 seconds and see if your noise goes away.