UPDATE 5-Hurricane Ida strengthens, 42 dead in El Salvador

* Floods, mudslides from rains kill 42 in El Salvador

* Ida could strengthen into a Category 2 hurricane

* Forecast to enter oil-producing Gulf of Mexico on Sunday (Adds details on coastal evacuations, conditions in Cancun)

By Michael O'Boyle

CANCUN, Mexico, Nov 8 (Reuters) - Hurricane Ida intensified off the Mexican resort of Cancun on Sunday and aimed for the Gulf of Mexico as the storm's heavy rains killed at least 42 people in El Salvador.

El Salvador's interior minister said more victims were expected to be found as rescue workers moved into areas cut off by flooding and mudslides in the Central American nation.

Ida reached hurricane status again late on Saturday, with sustained winds of near 90 mph (145 kph), the U.S. National Hurricane Center said in its 9 a.m. EST (1500 GMT) advisory.

The storm was poised to swing past Cancun and enter the Gulf of Mexico later on Sunday.

Ida could strengthen to Category 2 status on the five step Safir-Simpson intensity scale before starting to weaken on Monday as it churns towards oil and gas production facilities in the central Gulf of Mexico, the Miami-based hurricane center said.