We all don't agree on the statement that it just makes the bolt bigger yet, but I hope to give enough information to change that.
With the correct education most of us will come to an understanding.
Now on to the root causes.
#1 is the block and they did redesign it in 00. They also used a slightly different alloy blend. Well that has been what I have been told.
The 93 to 99 block have been known to leak coolant though the casting. Wait I have seen more leak oil than coolant.
This is a cross section
And another
One of the block I have in my garage had a leak after 3k from New. I repaired the by welding it, but I learned a lot about the root problem. It appeared that when the block was poured the aluminum splashed up the side. Then as the casting filled the part that splashed had started to cooled. The splashed part did not melt back into the casting. This block had a very small pin hole leak, but as I heated it a line formed. this line actually then grew into two parts with a grey substances in between. This was little waxy and it in part of the off gassing.
I have some pictures after it was fixed. :mellow: