Senate Finance Committee Chairman Bob Dole (R-Kan.) warned a group of Japanese legilators yesterday that his committee and the Senate will pass legislation limiting imports of Japanese cars unless Japanese automakers realistically restrict their car sales to the United States.

Dole and a dozen members of the Japanese Diet, led by Heiji Ogawa, chairman of the Liberal Democratic Party subcommittee on the auto industry, said they would like to see the auto-imports problem solved before Prime Minister Zenko Suzuki visits President Reagan early next month, according to Dole's press Secretary, Bill Kats.

Dole said he would like voluntary restraint by the Japanese instead of legislated quotas, but that his committe probably would mark up the legislation on May 12, pass it and send it to the Senate where it also would pass, Kats said.

The Japanese legislators didn't say how imports of Japanese cars could be limited or suggest a level at which exports to the United States would be held, Kats said.

The Japanese pointed out their cars weren't the reason for problems within the U.S. auto industry, and they said they are concerned that if they curtail shipments of exports here, many Japanese would be out of work, Kats said. "They were basically here to test the waters," he added.

According to congressional sources, the Japanese said legislated quotas would affect U.S.-Japan relatios adversely. Dole said, however, that the auto issue is causing political problems in the United States, and something has to be done about it, the sources said.

The legislation discussed was introduced earlier this year by Sens. John C. Danforth (R-Mo.) and Lloyd Bentsen (D-Tex.). It would limit imports of Japanese cars to 1.6 million annually for three years, 300,000 less than sold here in 1980. Other quota legislation would restrict imports to lower levels.

Meanwhile, U.S. Trade Representative William E. Brock yesterday told a National Town Meeting audience at the Kennedy Center that the Reagan administration intends to oppose import-quota legislation. "We can oppose it, and it's fairly obvious we intend to," Brock said.

President Reagan has maintained that it would be politically difficult for him to veto import-quota legislation although he doesn't favor it. Brock didn't say whether Reagan would veto the legislation.

"I would be delighted to see them exercise some prudence for awhile," Brock said. But he added that the administration would leave any import restrictions up to the Japanese and that the administration wouldn't try to impose any restrictions on them.