1990 chevy s10 blazer 4wd. Xmsn whines.

does yours have a turbo fitted as it can be this. if it dont go up or down with engine speed it can be somthing ells , like a wheel bearing catching brake shield ( onto the disc) or even the thrust bearing on the clutch. auto dont have this.

Could be your alternator or a bad idler pulley. Is the transmission good? It may be the tranny or your differential whining.

The most common cause would be a defective power steering pump.

Does the high-pitch whine exist when the engine is just running? Not moving (transmission is not in gear)? Running but with transmission in neutral (coasting down hill)?

think your starter motor is no good or the battery is flat ,try charging the battery for a couple of days as well

check fuel pump prasur

take off belt and try again onely for less than 5 min to see if it still makes noise

you have to remove the cover over the torque converter 4 bolts holds this on .you may be able to just move it out of the way. and yes it does sound like a starter problem.i hope this helps

This Noise Description sounds Indicative of the Sounds that come from the Serpentine Belt Or Related parts such as Belt Idler Pulley or Belt Tentioner witch also has a Pulley, but if Tensioner itself is Literally BROKE I've replaced a number like this it will cause a Whining noise . Best case scenario its just the Belt, and if any of the other Problems turn out to be the Culprit the Belt MUST be Replaced Anyhow as Damage is Being caused By the Very Whining you hear.
PLEASE Spend the Extras $ for the BEST BELT as this Drives your Water pump, Alternator, A/C Compressor, Power Steering Pump All Crucial to Control of, easy Steering ,All Electrical-Power Distribution, The COOLING of Engine << VERY CRITICAL Component
The Pulleys usually have a more Hum type Whining. So I would say at Best The BELT , And WORST Belt Tentioner is Broke

Sounds like the bendix is stuck in the starter. When this happens, the starter energizes and turns, but the gear does not kick out to make contact with the flywheel. Have someone tap on the starter while cranking the engine.