Ever wonder what is inside our beloved VVT pulley 
This what makes our Intake cam pulley advance by 30 degree with the help of OCV with the right manifold pressure, that received signal from ECU…
Thanx to DonnieB from hhttp://forum.9000rpm.net
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Then comes in VVT-i system…
Hence…the VVT-i pulley
which looks something like this :
Open the 4 bolts…this is what you see inside…
The cover plate off. During normal start or cold start…system goes to fully retard…once on operathing tempreture…system can go advance n retard back when ever needed…
More info on VVT-i noise…
VVT-i internal parts and how it works…refer to this thread - Celica Forum
==============DVVT===============
While we are talking about VVT-i, lets talk about DVVT.
which works similarly to VVT-i…
Here some brief picture of DVVT system…
Thanx to otromen from myvi forum
