That is most likely valve lifter noise, fist thing you can try is to change your oils and use an additive like Lucas Oil stabilizer, engines become loose as they age and weak oil can cause issues with lifters.
If you get no relief from theol change you may need to look into some valve work.
The 2002 Volkswagen Jetta's engine produces 122 ft-lbs. @ 2600 rpm.
The 2010 Volkswagen GTI's engine produces 207 ft-lbs. @ 1800 rpm.
The 2006 Volkswagen Passat's engine produces 207 ft-lbs. @ 1800 rpm.
The 2005 Volkswagen Touareg's engine produces 229 ft-lbs. @ 3200 rpm.
The 2013 Volkswagen Beetle's engine produces 177 ft-lbs. @ 4250 rpm.
The 2007 Volkswagen Touareg's engine produces 266 ft-lbs. @ 3200 rpm.
The 2014 Volkswagen Golf's engine produces 177 ft-lbs. @ 4250 rpm.
The 2004 Volkswagen Jetta's engine produces 122 ft-lbs. @ 2600 rpm.
The 2007 Volkswagen Jetta's engine produces 170 ft-lbs. @ 3750 rpm.
The 2010 Volkswagen Touareg's engine produces 266 ft-lbs. @ 2500 rpm.
The 2010 Volkswagen Jetta's engine produces 177 ft-lbs. @ 4250 rpm.
The 2012 Volkswagen Jetta's engine produces 125 ft-lbs. @ 4000 rpm.