My car was idling like crap the other day so I figured since I just got it, it may have been awhile since anyone changed the oil out. I decided to go ahead and change the oil. I used Mobile 1 synthentic oil like I was reccomended on here. Anyways, I drain out the oil and noticed it was extremely dark and even after 10 minutes of draining, it was still coming out. I decided to go ahead and flush it to make sure all the bad stuff got out. I hooked up the hose, ran water through the engine, started it up and was waiting for the water to come out clean (The engine never went above idle so I was told this would be ok). Anyways, About 3 minutes into this, then engine starts shaking and shuts off. I figured it was all cleaned out so I plugged it up, added the oil and figured I was ready to go. WRONG! The car won't freaking start now. This car has been nothing but trouble for me, I think I am done with it.

http://www.mustangforums.com/forum/showthread.php?t=368307