I have a 87 z28 305 there's a slight tapping noise seeming to be coming from the engine car runs fine well runs a little rough from about 20 to 40 MPH then Runs fine there's a vibration when accelerating also when I changed the starter the bolt from the exhaust to the engine was corroded and came right out but tapping isn't from exhaust where to start or what the tapping noise signifies????

 

you need to hunt it down because noise can come from anywhere..........................including exhaust leaks so don't be so quick to discount the exhaust

 

Hmmm ok thanks let me take care of the exhaust and go from there see if that helps

 

Yeah there is so many things it could be

 

Any other way of going about it other than process of elimination? ?/?

 

When my car was making tapping noise I just pulled the valve covers and intake off and started looking around. Turns out whoever owned it last put to long a bolt to hold down the intake and it was tapping on the rod.

 

But then I'd be tapping all the time wouldn't it?