I recently purchased a 2014 Passat 1.8T S Automatic with 70K miles on it.

I noticed a sound that happens when accelerating. It's very faint, but it's more noticeable at low RPMs. I can't hear it when in neutral or when cruising. It doesn't matter if the engine is cold or warm. It's a little hard to explain the sound, but it's like a faint thumping sound. Here's a link to it:

In the video I'm driving very slowly through a parking lot. I'm accelerating and then letting go of the gas (I keep repeating the process).The noise I'm referring to can be heard best around 7 and 13 seconds.

I took the car to a VW mechanic. He stated he could hear the noise and also later stated he heard a clicking sound from the engine (I couldn't hear it). He plugged it into his computer and stated it wasn't idling smoothly. He inspected the timing chain and noticed the magnet was sticking and replaced the magnet. There’s some kind of rod or something that indicates the wear on the timing chain (timing chain tensioner?). He stated you could count the rings on it and it should measure between 1-3, and the recommendation is to replace it right away if it measures 7 or above. It measured 6. He believe the noise he heard and the one we heard together were related. I was quoted $2,300 to replace the timing chain (before tax).

The VW dealer gave me a list of the specific parts needed to be replaced and I started shopping around for a better price. I found a local German Car repair shop with excellent online reviews. They quoted me about $1500 (including tax) for the same job. However, they wanted to look at it first prior to doing the work because they stated it's rare for the chain to fail on this car at those miles. I brought it in and they stated they did not see/hear anything indicating the chain needed to be replaced. I paid them $50 for the diagnosis. They didn't seem to worried about the sound I was referring to. Initially they stated it might just be natural for this model to make the sound. Later that it could be related to the transmission, but if I wanted them to go further I would be about $100 for them to start using a listening device (a stethoscope maybe?) to be able to isolate the problem, and if I really wanted them to continue going down the timing chain route it would be another $100. They reiterated they did not see or hear anything indicating it was the timing chain. Since it didn't seem like a big problem I took the car back.

But the sound keeps worrying me. Does anyone have thoughts on the sound, or on above in general?

Sorry for the long post....