Hey guys, my solstice is starting to worry me. The rear end makes awful grinding noises when turning. I've service the rear end with lsd additive several times which makes it quiet for about 3k miles but it goes back to grinding again. Secondly, and perhaps more troubling, when I start the car, I get a really loud rattle/slapping noise for a few seconds. When I turn it off, I can here a small knocking noise as the engine comes to a stop. When driving down the road, I head something that sounds similar to spark knock but I've used premium in it forever for whatever reason. I've noticed a significant loss in power. So, all this leads me to believe I have some chain stretch going on. Is this possible or common? My car is 10 years old with 123k miles on it. It has the original water pump. And I've never seen the check engine light come on so I don't know if it even works. Any ideas on how to approach this would be great. I really want to avoid a car payment of at all possible.