No longer found in petrol dumps (3)
I believe the answer is:
old
'no longer' is the definition.
(both can mean former)
'in petrol dumps' is the wordplay.
'in' says the answer is hidden in the clue.
'OLD' can be found hidden inside 'petrol dumps'.
'found' is the link.
(Other definitions for old that I've seen before include "At an early stage - at a late stage" , "Venerable" , "Former, previous" , "Elderly" , "Stale" .)