96 100" limo screeching from engine

[megliam]

Theres a screeching noise ( i thought like a slipping belt) from my engine.
it is really loud on start up from cold & gets quieter as it heats up, it seems to be at low revs and also when taking my foot off the gas at around 20-30 mph.although it gets quieter it never goes away completely.
the previous owner said he had the serpentine belt changed out in march but I think it loks a bit glazed ( especially on the smooth side )
does this make a difference.
Also can the tensioner pulley be adjusted or is it self adjusting in one position only.

the car drives beautifully but the noise is irritating especially as it is going to be a working limo ( i hope !!!)
thanks in advance for all info, greafull appreciated.

[lincoln_mark_8]

check the tensioner pulley and the alt pulley for free play. They should turn free. You will have to remove the belt to do this. You will have to replace the belt as well when you find and fix the problem.