'91 300zx n/a Water pump failure (Recurring Issue) NEED HELP!

[Brandon._.Z32]

So I have a 1991 z32 n/a with 265xxx miles on it and for the past 2 years I really haven't
been able to drive it very much due to the issue of the alternator belt always squeals
at startup and then any time the rpms drop low when taking off from a stop. Sometimes I can rev
and it'll go away and other times it won't. If I tighten it till it stops then it seems to be too tight for
the water pump as my water pump keeps breaking. I'm at a loss after trying everything I can to fix the
issue as I have thought it may be belt misalignment or a pulley issue im really unsure anymore but I
would love to drive it this summer, I used to daily the car until this issue
I bought another car and parked the z. so far I have replaced everything listed below any help would
be greatly appreciated.


Water pump
Water pump pulley
Crank Pulley
Alternator tensioner
Alternator Bracket to motor
All OEM belts

[scottgas]

How old is the belt? Have you tried a fresh new belt since the issue started? If the belt squeals it means it is slipping which means heat and friction which means premature wear.

[NolimitZ32]

I had a terrible belt squeal when I was running an aluminum pulley on my alt. The alt will usually produce the most drag under normal operating conditions so check that pulley. Checking the condition of each of the pulleys' grooved surfaces should help identify which is slipping.

[Brandon._.Z32]

So back to my Z after quite some time as the car has just been sitting. Today I made the effort to get it back on the road and I'm addressing this issue, but yes all of the pulleys have been replaced due to this issue and it doesn't seem to be misaligned. I'm really stumped on this issue but am determined to figure it out. Any other suggestions would be greatly appreciated. I'm all ears and ready to try whatever at this point!

[NolimitZ32]

Are you certain its the alt pulley that's squealing?
How many Water Pumps have you broken and what failed?
How did you gauge the "straightness" of your pulleys? I've had pulleys that "looked" straight but once a belt ran over them it was plain to see they were ~5 degrees off which will wreak havoc on your belt drive.

[Brandon._.Z32]

Hey there, So upon trying to figure out the issue in the beginning i had adjusted belt tension and such to try and resolve the squeak however it wouldn't go away and at one point the belt slipped off leaving only my p/s belt on and the squeak was gone for the few min it took to get to a good pullover spot, Also removed the p/s belt at one point just to single it out and the squeal persisted, Thanks in advance! Also I went through about 4 before parking it and just driving my other vehicle sadly, I honestly just eyeballed the straightness of the pulleys they "look" straight, and suggestions and or tips are greatly appreciated!