Old note found in burnt out part of engine (8)
I believe the answer is:
turbofan
'part of engine' is the definition.
(fan driven by a turbine)
'old note found in burnt out' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'note' becomes 'fa' (fourth note in sol-fa notation: doh, ray, me...).
'found in' indicates anagramming the letters.
'out' means one lot of letters goes inside another.
'burnt' is an anagram of 'turbn'.
'o'+'fa'='ofa'
'ofa' placed into 'turbn' is 'TURBOFAN'.
(Other definitions for turbofan that I've seen before include "Type of jet engine" , "aircraft" .)