I have this clunking sound that occurs at random times, but always at lower RPM and with the trans in gear. Sometimes the noise is accompanied by shaking and hesitating. I thought at first that I may have a bad motor mount, but the problem comes and goes.
There has also been this thing where at times when I accelerate, there is this pop sound that comes from under the hood. It is always one solitary pop, but it doesn't always happen.

 

ok, so this problem is getting worse. at low rpm, especially when I first start driving (not necessarily if the engine is cold, sometimes I will drive somewhere and when I start driving again, it starts happening again) the engine shakes and hesitates. It is worst when in gear, but now when I put it in neutral, it feels like the whole car is slightly bobbing up and down, sorta like the way a washing machine does when it's off balance. In neutral there is no noise associated with the movement, just when it's in gear (D or R). It's really running like crap and it's getting worse. Can anyone offer any help?

 

Check your spark plugs, make sure they're in right. This might not be the solution but an attempt...

 

Thanks, that's exactly what I'm about to try, thanks for the info!