[Konstantinos]

Use a timer for it:

pawn Код:

// global:
new Something_Timer;

// in OnGameModeInit or OnFilterScriptInit (depending on your mode):
Something_Timer = SetTimer("OnSomethingUpdate", 5000, true);

// in OnGameModeExit or OnFilterScriptExit (the same as above):
KillTimer(Something_Timer);

forward OnSomethingUpdate();
public OnSomethingUpdate()
{
    // code to check for something..
}

You can replace "Something" with its name of it, I used it as example only.