Hi i have a 88 chevy silverado 2500, when i floor it from any speed almost all the time there is a grinding noise that sounds like its comeing from under the hood, also the check engine light will come on once i do it, but it shuts off next time i start the truck. Please help me out i have no idea where to start looking.

 

So it doesn't do it when you are parked and floor it??

 

I would say to check your motor mounts, have some one that you trust put the truck in drive and reverse while holding the brake and take a look at it. If it moves enough to hit the sides then there is your problem. Something is hitting and grinding on something else, you just need to find the bare metal!

 

True that. One time I had my air filter box doin that cuz it was loose.

 

If I had to guess, I would say it would be the fan hitting the sides of the shroud. Or a bet driven item hitting another solid object.

But I would check the motor mounts first.