My engine sounds a little ... rough. I don't really know how else to describe it, but it doesn't sound right. Pretty much sounds normal until about 3k rpm, then it sounds like it's working harder than it used to. I also smell a faint burning smell from the engine bay when I start the car. The last thing, (might be completely unrelated) my BOV sounds completely wimpy all of a sudden.

What do you guys think? Should I be saving up for a rebuild? I got 104k on the original engine, btw.

 

Get a compression test and pressure test the coolant system.

 

Yep, do this first.