The debris fell to the west of a new emergency relief route, leaving local drivers with the options of a 50-mile detour using the A82 to Crianlarich and Tyndrum, or travelling by way of the Gourock to Dunooon ferry throughout yesterday.
The Met Office last night issued a yellow weather warning for Strathclyde, with further downpours expected until midday today.
The upgrading of the nearby Old Military Road as a relief road in February, using some of the £3.7 million Government money to deal with landslides, was meant to avoid a repeat of the on-going problem.
But the latest slip was too far to the west for this new emergency route to be of any use.
The A83 re-opened last night.
Meanwhile, the A82 is due to close on Monday, overnight for two weeks to allow roadworks at Pulpit Rock, on Loch Lomond-side, starting on Monday.
Concerns are being raised about further landslides on the A83 during this time.
Transport Scotland said a decision on whether the Loch Lomond works would proceed as planned, would be taken once the A83 was cleared and assessments were made.
Heavy rain washed an estimated 100 tonnes of debris on to the road between Arrochar and Inveraray at about 7.30am, but not at the same point as previous closures. This time it was in Glen Kinglas, between the junctions with the B828 and A815.
Argyll and Bute council leader Dick Walsh said: "We are concerned to make sure Argyll and Bute remains open for business, especially with the October school holidays approaching, and to make the most of the last few weeks of the vital tourist season."
He said that following the landslide, the council had written to Transport Scotland about contingency planning for the A82 works at Pulpit Rock.
"The people who visit, live and work in Argyll and Bute depend on these routes and we need to ensure that they are able to go about their business."
Adriano Pia, owner of the Royal Burgh Cafe in Inveraray, said: "We decided to close today in light of the landslide. It just wasn't worth opening, bringing in all the staff just to stand around. So we made a collective decision not to open today. There has been one bus come into town this morning, whereas last Thursday we were pretty busy."
He thought it was worrying the road was closed at a different point.
Anne Boyd, who owned the Coffee House and Poachers Restaurant in Inveraray for more than 20 years until she retired in 2011, said she was well used to the road being closed. "It makes a tremendous difference. It could cut your business by at least half. And this time it is not where all the work was being done. Another section now seems to be needing attention. It is all very depressing."
Brian Gordon, managing director of BEAR Scotland, which is responsible for local roads said: "Safety is the top priority."