The most common and most likely answer to this crossword clue is the 6 letter word PISTON
I've seen this crossword clue in The Times
P
I
S
T
O
N
More clues leading to the result PISTON
- Odd points identifying part of engine
- Part of pump beginning to swivel stops mine working
- Odd points in trumpet part
- Reported drunk on machine part
- Points out engine part
- Iron peg securing special valve mechanism
- Sump is to necessitate purchasing engine part
- Replace points in part of car engine
- No pits can supply what’s needed in engine
- Mechanical device — power is coming with great speed
Buddy explains!

The straight part
We know that "part of engine" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of engine = piston.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PISTON mean?
PISTON noun- A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)
- A valve device in some brass instruments for changing the pitch
- To move up and down like a piston.