Chevrolet Blazer sound

have you checked out your starter and solenoid yet

There is really no way to know what the noise is, you must have it inspected and well you have it in the shop have the engine control computer scanned for fault codes, when the CEL is on the system will set a fault code for the problem that turned on the Check Eng. Light.

check emitions,trouble codes,check idle circit sounds like something returns to normal each time you turn the key off,trouble code may show area of problem
hope this will help you find it

The rattle is likely a loose shield or a bad catalytic converter. As for the loud banging, Have you checked the front U-joints behind the brake rotors. As for the Reverse noise? Auto or stick shift?

Lube the tie rod ends, center link, upper and lower ball joints, and steering link. If noise is still the same, you probably have worn upper or lower control arrn bushings or a steering box problem.

Are motor mounts good? You'll definitely hear it when the engine torques up and then bang back down.

yur transmission just went

Sounds like a weak battery. Have is checked, it sounds like the reserve capacity is gone.

no idea
take it to an accredited service center for a proper diagnosis and quote
initial cause was probably a lack of pre use inspection

This is Caused by a Pinion Gear Tooth being Broken off inside the Rear end. Eventually this will get worse and wind up Shelling out the Rear end. You can Rebuild the Rear end or Get a Replacement But, One of them will need to be done Pretty soon. Please Rate My Response! Thanks!