1996 Maxima 141k mi. Having squealing and choking problems

[proto88]

Hello Everyone, I am having some issue with my '96 Maxima. Problem began on Thursday when my car decided to die on me at the intersection. ABS and AirBag Lights were on, engine light, radio cut off, and car did not start. Got it towed to mechanic and figured out it was the alternator. Apparently the alternator (connector/harness) melted. The mechanic replaced,belt, and reconnected the connector, car started fine, overpriced but fixed ($600 had no other option ). Drove the car on Friday with no issues. Now it's Sunday and new problems are surfacing.

Problem 1: There is a squealing noise near the belt area (only squeals at 500-900 rpm), squeal only goes off when it is in drive and at those rpm. Anything higher than 900 rpm the squealing stops.

Problem 2: When car is idling in drive gear(500-700 rpm) it shakes, feels like its going to stall.

Problem 3: When I take the car out for a 10-15 block drive (local, and not mashing on the gas), the engine bay gets really hot.

Does anyone know what is causing the squealing and shaking? Could the shaking be caused by bad spark plugs?

[NutriaforBreakfast]

I would check the idler pulley first to be sure this was
adjusted correctly for the new belt. He may not have realized you have to loosen the pulley bolt and work with twisting the adjusting mechanism.
Some think just twisting the mechanism is all you have to do

Use an multimeter to check and be sure your alternator is putting out enough current. There are several threads on the website for this

check and make sure the repairman didn't leave a vacuum hose off when
he made his repair