I have a 2004 grand prix series 3 3.8 L non supercharged gt2 does anyone know if this engine is prone for failing I'm on my 2nd engine just started the dreaded rod knock first engine did the same thing 1st engine had 130k 2nd 70k engine was installed by certified mechanic. I'm not hard on my car and I change my oil and I don't use penzoil what the heck is going on