President Reagan intends to nominate as his new ambassador to Mexico Charles J. Pilliod Jr., who headed the Goodyear Tire & Rubber Co. in 1977 when it admitted making $2 million in improper payments to foreign officials. Securities and Exchange Commission charges against Goodyear at the time included payments to some officials in Mexico.

Administration sources said yesterday that Pilliod, 67, would replace former movie star John Gavin. Pilliod was board chairman and chief executive officer at Goodyear from 1974 to 1982.

In 1977, the nation's largest rubber and tire maker disclosed that it had paid $2 million to officials in India, Nicaragua, El Salvador, Taiwan, Algeria and four other unnamed nations, all in Latin America, between 1970 and 1975.

The firm, which acted under threat of a civil injunction filed by the Securities and Exchange Commission, said at the time that its executives had no knowledge of the payments, and no charges were ever filed against Pilliod.

The SEC complaint charged that Goodyear had paid officials in more than 20 nations, including $134,000 to a Mexican rubber manufacturers' trade association official, "in connection with obtaining government approval of the industry price increase for tires."

The money allegedly came out of a $1 million unreported fund that the SEC said Goodyear maintained between 1970 and 1976 "in connection with its foreign operations."

Pilliod ordered the internal investigation at Goodyear in 1975 that led to the findings after Watergate-era probes found secret corporate political "slush funds" at other companies, according to reports at the time. Goodyear also contributed $40,000 illegally to Richard Nixon's reelection campaign in 1972.

The administration hopes to bring Pilliod's nomination before the Senate before the July recess, officials said.