The Carter administration has intensified its internal discussions and diplomatic activity in recent weeks in the search for a solution to the hostage crisis with Iran, but officials said yesterday that no breakthrough is in sight.

Administration sources who were unusually guarded in their comments conceded that an all-out effort to obtain release of the 52 Americans is likely between now and Election Day, Nov. 4, which also would be the first anniversary of the seizure of the American Embassy in Tehran.

A senior administration source said the hostage-release effort is in a very active stage, with elaborate plans drawn up within the government to meet various demands that have been put forward at different times in the recent past by different factions of the Iranian power structure.

The Iranian executive apparatus headed by President Abol Hassan Bani-Sadr has made plain in public and private its desire to solve the problem of the hostages under negotiated arrangements with the United States. pHowever, Bani-Sadr's longstanding wish for a settlement has been thwarted consistently by clerical factions in the Iranian power structure.

There is yet no indication that the Iranian clerics have decided to move toward release of the hostages, or even to authorize direct negotiations with the United States toward a negotiated arrangement. Thus the hard-line elements in Tehran remain the practical barrier to a solution soon.

Prior to the Iran-Iraq war, some high U.S. officials were optimistic, on the basis of soundings from Tehran, that the time was near when Iran would be ready to seriously consider the hostages' release. Part of the mission of a secretive trip to Europe Sept. 14-18 by a U.S. delegation headed by Deputy Secretary of State Warren Christopher was to explore a potential settlement.

When the Christopher trip became known, officials denied that he or his traveling companions, including the senior U.S. experts on Iran from several government departments, had met with Iranian Central Bank Governor ali Reza Nobari, who was in Bonn at the same time. But there have been persistent reports that members of the Christopher mission met with other Iranians while in Europe.

The full-scale Iraqi invasion of Iran, which began Sept. 22, shortly after Christopher's return, added an unexpected complication to the problem of a negotiated settlement. Despite U.S. declarations of neutrality, Iran has continued to insist that Washington had a hand in fomenting or even planning the Iraqi attack. Along with the overwhelming concentration on the war itself, this widespread assertion of American involvement seemed to impair the climate in Tehran for a negotiated deal.

As the fighting with Iraq has continued, however, some elements in Iran have become more keenly aware of the consequences of Iranian international isolation due to the hostage crisis, including the difficulty of obtaining spare parts, ammunition and other military and civilian supplies needed in wartime. Thus there was renewed hope among U.S. officials, especially early last week.

Reports circulated in Washington yesterday that the administration was looking into ways to provide military spare parts to Iran through third countries in a deal linked to the hostages. While acknowledging that rumors are widespread, officials who have been involved in the U.S. policymaking on the issue denied that a spare-parts-for-hostages arrangement is being worked out.

A similar denial came last night from Ali Shams Ardakani, chairman of Iran's special delegation to the United Nations General Assembly. Interviewed on the Public Broadcasting System "Mac-Neil-Lehrer Report," Ardakani dismissed the idea of swapping spare parts for the hostages by saying: "The best thing is to disassociate these two questions. If we try to connect them, it will not happen."

Ardakani, who is associated with the Bani-Sadr faction within the Iranian power structure, said he believed the hostages could be released quickly if "the United States would move toward stopping its ridicule of the Iranian revolution," agree to listen to "the grievances of the Iranian people" and make some "positive response" to these grievances.

Although he would not specify what the response should be, he hinted strongly that the impasse over the hostages could be broken quickly if the United States releases the approximately $8 billion in Iranian government assets frozen by President Carter. Until now the administration has insisted it will release the assets only as part of an overall agreement that would lead to the guaranteed release of the hostages.

According to one official, the rumors seem to have originated in Defense Department contingency planning. Another official attributed the spate of rumors to industry representatives in the military field.

Campaigning yesterday in St. Petersburg, Fla., President Carter said he has "no idea" when the hostages may be released. In an interview with WTVT-TV he said "we have hopes" but "no expectations" that it may be soon.

Asked about the likelihood of an "October surprise" from overseas that could affect the presidential race, Carter said it would be "a surprise to me, too." He added, "I don't know of anything planned . . . There is no way to try to contrive some sort of false surprise to be sprung on the American people just before the election."