Will the engine break immediately if sand gets into it?

[Lincoln]

If sand indeed enters through the intake port, it can cause damage in less than a minute. Generally, sand doesn't get in unless the air filter is removed, and even then, it's mostly dust, which isn't good for the engine. Dust entering through the throttle body won't immediately damage the engine either. If you've changed the oil, monitor oil consumption more closely and shorten the oil change interval. A qualified oil filter can remove most particles. Additional note: If sand actually gets inside the engine, simply changing the oil won't suffice because sand is heavy. You'll need to remove the oil pan for cleaning, then use cleaning oil to flush the interior. Remember to repeat the process several times to minimize damage. Check for oil burning. If the problem persists, the only solution is to dismantle the cylinder.