How many miles has it done? These are prone for cam-belt fluff/debris clogging the oil ways (wet belt setup).

First thing to do would be remove the VVT solenoids and check the filters - if they're clogged - you're going to need to get the sump off and clean the strainer - oil pump, replace the oil pressure control solenoid and the VVT units.....

Yay - cam-belts - keeping garages in work since their conception!