Need so help guys. Brought a 96 mark about four months ago. When I brought the car it had 89,000 on it. It ran good and doesn't smoke, only thing it had a slight ticking noise in the engine. I had manual oil pressure test done and everything was ok. The tick appears to go away when rpm's are raised. Today after leaving work I noticed at Idle car was running really rough and accelerated really rough. What could it be or what are my next steps?