Boy, if that is not the truth. I worked at the time for a company that built test equipment. We had the pleasure of leak testing the heads and blocks for the original Trailblazer. They used the lost foam method for the castings. The end castings were so porous that oil was literally weeping out of the blocks and dripping onto the floor. So, then they got the swell idea that they would leak test them and if they leaked, send them to an impregnation process to vacuum in a sealant into the pores. They were allowed to fail until they hit 3 times and then finally scrapped. If they failed multiple times, they were impregnated multiple times and then sent back around.

Never forget going onto the pre-assembly production line. They were not getting enough through-put from the line. Leak test was basically turned down to zero, with nothing really being checked. They wanted to know how to get more parts through the line as leak test was taking too long (too long being literally not checking anything). Luckily we walked away from that one.

GM has a long history of producing steaming dung-piles for vehicles. They prey on the "I must buy American" false pretense that draws old-school buyers into still buying pathetic garbage. All you have to do is look at the resale value for 1 and 2 year old GM's to really understand.