So I got a 1990 Laredo a week ago and at high RPMs (3500+). I think it sounds cool but is there anything that could be wrong to make that sound?

 

General area of sound would deff help ?

 

Water pump bearings, power steering pump?

 

Water pump, alternator, idler pulleys, P/S pump, A/C compressor.

A mechanics stethoscope helps pin point these things.

 

I did the ZJ fan clutch upgrade a while back and mine sounds kind of like a turbo now at higher RPM's. A lot of folks on here said it would sound that way but mine isn't too loud...and I know that it's working right.

 

Engine compartment

 

Have you opened the hood and taken a peek at anything?

 

Yes, but I haven't checked any pulleys for play. I'll go do that now

 

Gotta get you ear in there and listen no way around it...

 

Does clutch fan spin ?

 

There are some good suggestions here. Another thing to check is possible leaks in the air intake system.

 

When in doubt, Remove the fan belt and rotate every pulley by hand. one should feel wrong. if you don't find anything, You can even start it for a min or so (if its cold) and listen if the sound is coming from the back of the engine.

most unlikely but possibly, I rebuild my 88 engine and put it in a 98 with the fan belt routing of the 98.
I had this weird winding noise as well and couldn't find anything wrong then noticed that the belt was rubbing against a piece of the timing chain cover (didn't know they where different from year to year). Fortunately, there was about 1/2 " of material I could just file off and solve the problem.
The reason it was making that sound is because I have the type of belt that has little squares on the pulley side, not just the single grooves.

 

I can turn it but it doesn't spin.

The idler pulley has some play in it, I think I found it.

 

Got front pump on tranny also a possible whiner..

 

Just replaced mine autozone under 20 bucks