Workplace no longer using internal combustion engine (6)
I believe the answer is:
office
'workplace' is the definition.
(I've seen this before)
'combustion engine' is the wordplay.
'combustion' becomes 'off' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'engine' becomes 'ice' (I've seen this before).
'off'+'ice'='OFFICE'
'no longer using internal' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for office that I've seen before include "Post - bureau" , "Business premises" , "Position, or building in which colours in layers" , "Place for administrative business" , "Professional or clerical duties are performed here" .)