Your phase position angle is -4deg.

 

Great, thank you very much! I guess that means it needs to be done.

 

TBH though that guy's video is IMO, hands down the best for changing that chain, the VCDS measurement there is not really all that useful on these motors. Typically speaking this chain does not "stretch" to the point where it causes catastrophic failure and can usually be driven until there's either audible noise being made or you get the engine light on. That's as far as the chain itself goes. The real problem here (which honestly isn't that common a problem) is the tensioner failing in some way--either the tensioner itself or the plastic guides on it break.

How old is your car and how many miles are on it? Note that a rattle at cold start, which goes away after a few seconds, is not indicative of a tensioner failure. Audi says it's normal if the oil in the tensioner has drained down as it needs a few seconds to build back oil pressure and "inflate" normally.

 

It's 2009 with 122k miles

 

If it has never been changed, I'd consider changing the chain and tensioner. If you're going to DIY it, then the video above is exactly what you want to watch for the "how-to".

Presuming your timing belt was done at 110k miles, you won't need to worry about doing that as well.

I changed mine on my car when I got it (MY13 with about 115k miles when I bought it). TBH the old one was perfectly fine--plastic guide and all. I changed it anyway since I'd already bought the parts.

 

Okay, maybe I'll put it off another year or so since it's currently not causing any issue and I don't do many miles. I'm 'okay' at some DIY stuff although nothing ever seems straight forward when I try to do it! Is it an expensive job?

 

I'd say it's probably "in the middle" in terms of pricing. It's not going to be as pricey as the timing belt but also not going to be too cheap either. It's a bit tricky a job because of the bolt that holds the adjuster and having to have the right bit to take it out (the bolt should also be replaced afterwards), along with the cam counterhold tool. If you're getting it done at a shop, be sure to get it done at a shop well versed and experienced in doing these--any VAG-specialising shop should be.

 

I changed mine at 165k it had no rattle but was on -8 so as a precaution i replaced it