I found out what was the problem with my car making a grinding noise whenever i went in reverse. It was the idle arm on the motor. Not sure what part this is or what is does. Maybe you might know what it is?? Turns out it was not the motor mount that was bad. My motor mounts are fine. Just had to get that idle arm fixed in order to pass inspection today. Did not cost alot to get fixed..about $150. Do you know what an idle arm is and what it does?? thanks.

 

I don't know why a failing or failed idler arm would cause grinding unless it was really gone, but then I would think it would have some other drivability concerns associated with it...

The idler arm is part of the steering linkage. It is located on the passenger side right near the frame rail and is what supports the passenger side of the steering linkage.

 

Yeah, sounds strange. But, if its not the idle arm or the motor mounts, what can be causing this grinding when i go into reverse?? Its comming from the motor compartment and is very loud even with the windows up. Its driving me nuts thinking there is something wrong with my blazer. But when i go into drive it stops. Has to do something with torque or something, switching of the gears and the directions the motor is turning or something. Maybe a transmission, but i have no problems at all switching gears, its a automatic. My RPM are fine and gear switching when in drive is just fine. Does not make the sound when i am in park. minute i switch to reverse it makes the sound.

 

Might be in the valve body. When you switch from park to reverse (or does this happen from any gear to reverse?)

if either you are probly looking ateither: replacing your shifter cable and if that is fine with no slop then you are looking at your valve body in the transmission.

And if only from Park to reverse,I would dig into the valve body or replace it.

 

I had a chain lube shop tell me my idler arm was bad causing all sorts of issues and that my ball joints were fine, when actually, I had worn ball joints and a fine idler arm (thankfully I knew that going in, so I didn't get suckered into paying). Gotta watch out for what the places tell you sometimes..

 

wait, do you mean the belt tensioner pully?? Yes they can make a grinding noise and all kinds of wierd other noises.. The one of my chevy van went bad -the sounds they make can be embarrasing...