The House begins debate today on the Chrysler loan guarantee bill, but the measure faces a filibuster threat in the Senate that could delay federal aid beyond Chrysler's January do-or-die date.

The auto company has said it will go bankrupt unless it gets federal help by then.

Although the Senate also is expected to start work on the measure today, Sen. Lowell P. Weicker Jr. (R.-Conn.) has threatened a filibuster that may block action on the bill until Friday -- too late to go through a conference committee before the scheduled Friday adjournment.

House Speaker Thomas P. O'Neill Jr. (D.-Mass.) told reporters he did not see how the bill could clear conference before Congress goes home this weekend, and is planning on calling the lawmakers back on Jan. 3.

Meanwhile, Chrysler officials, reiterating their warning that the firm will run out of cash in January, began efforts to amend the Senate bill to allow an interim federally guaranteed loan as soon as the measure passes.

Neither the form of the amendment nor the size of the interim loan involved had been agreed on by proponents yesterday. The House version of the bill would allow an interim loan.

House leaders said yesterday they hope their chamber can finish work on the Chrysler legislation today, although formal approval could be delayed until Wednesday if floor managers are faced with many amendments.

In the Senate, Majority Leader Obert C. Byrd (D-W. Va.) has served notice he will file a petition on Wednesday to cut off debate on the Chrysler measure -- and end any filibuster by Weicker -- but that may not leave much time.

Under current Senate rules, if Byrd files his cloture petition on Wednesday, the vote to close off debate would not come until sometime on Friday. Weicker says he simply is opposed to the Chrysler measure on principle.

The majority leader tried to get the Senate to take up the Chrysler bill last Saturday night, but was blocked by Weicker, who complained that the measure was being "rushed" through.

Chrysler officials announced last Friday that because of lagging auto sales the company will run out of money in January rather than February as thought earlier, and so will have to seek a bridge loan to tide it over. The Senate bill would prohibit such a move.

The key question in the issue is how long it would take the company, the United Auto Workers union and the banks involved to complete the complicated arrangements the new legislation requires before the government could underwrite any loans.

Under the Senate version of the bill, the loan guarantee would not become available until all sides -- Chrysler, the UAW and the banks -- signed binding agreements to carry out the terms of the legislation.

By contrast, the House version of the bill would require only a nonbinding "commitment" by these parties.

Chrysler officials said yesterday they estimate it would take about a month for the banking and stockholders' requirements to be met, but there was uncertainty over another element -- the renegotiation of Chrysler's contract with the UAW.

The House version of the bill would require UAW members to forgo about a third of the $1.3 billion in wage increases they have won over the next three years, while the Senate measure would freeze their wages at current levels.

Chrysler reiterated yesterday that any interim financing it obtains under the loan guarantee legislation would be counted against the $3.3 billion package now being envisioned, and would not require additional federal monies.

Approval of the Chrysler legislation is expected to come relatively easily in the House, but the outlook in the Senate is still uncertain. Lawmakers report the aid-to-Chrysler effort is not proving popular, even in auto-producing states.