06 Jetta Ping/knock noise
 

I have an 06 Jetta with 5sp manual and the 2.5 gas 5 cyl. It has 55,000 miles on it and the last week or so I notice a small knock/ping sound. It doesn't do it when I just rev. it up in N., but when going 40+ mph and give it a little gas I seem to notice it. Anyone else had anything similar? It doesn't really sound quite like the old ping you used to hear in old V8 engines when the timing was off a little, but that's kinda what it reminds me of. It sounds a little like it may be coming from closer to the underside, like maybe a cv joint or something like that.

Thanks-