I was driving my car yesterday and it started breaking up and missing. It would shake violently at anything more then half throttle or higher then 3k rpms. then i pulled the antifreeze dipstick and saw black gunk on the stick. I figured it was oil and a blown headgasket so i stripped it down this morning. so far accesories and manifold is off. i noticed a pushrod on the driver side head was sitting crooked. I pulled the valve cover and apparently the rocker loosened up and the pushrod was sitting sideways not connected to anything. Could this of been why it was breaking up? I also drained the antifreeze and by visual check the antifreeze looks as green as can be with no oil residue in it at all. I'm confused bigtime?

 

Yes!!

 

If no one has cleaned the coolant reservoir out in 11-15 years (we have no idea what year your car is, because you don't have a "signature") is wouldn't be unusual to find "gunk" in it.