i have a 2000 blazer 4x4 LT and i noticed first when i would put the car into reverse my engine fan would grind badly and would stop as soon as it went into drive, now it is doing this when first starting the car and when i am driving. i have looked at the fan and see where it is rubbing on the bottom of the shroud i don't know if the motor mounts have broken or not any ideas for me?

 

Eh i doubt its the mounts. Pop the hood,get someone to put it into drive/reverse. tap on the gas. You can tell if you have a bad mount by watching the engine

 

Bad motor mounts can certainly cause the fan to hit the shroud. Check them or have them checked.

 

I have a 2000 LT, and broke both my motor mounts in 4Low not realizing it for a while. My fan never hit the guard at all. The only thing it did: a large bump when I pumped at the pedal while it was in gear, or pulling that boat.. But I'm sure if I got on like a maniac, the fan would have struck the guard.
These motor mounts are kind of pathetic. They are made out of a 'pop metal' type material.. I got mine at Napa, they seemed to be the best quality from the others.