"High frequency indicators - including loan growth, vehicle sales, government budget disbursement and trade - suggest weak activity on almost all fronts," said Chua Hak Bin, an economist with Bank of America Merrill Lynch.
The median forecast of 22 analysts in a Reuters poll is for second-quarter growth, due for release later Wednesday, of 4.61 percent, even weaker than the 4.71 percent growth posted in January-March.
The failure to galvanise the economy was reflected by weak corporate earnings. Astra International, a major conglomerate, Semen Indonesia, the country's largest cement maker and Indofood Sukses Makmur, one of the world's biggest instant noodle makers, have all disappointed.
A rare bright spot was foreign direct investment (FDI), which on an annual basis grew at irs fastest pace since 2013 in the second quarter, according to investment board data that excludes investment in banking and the oil and gas sector.
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Manufacturing activity looked to have stayed weak, contracting for a tenth straight month in July, according to a Nikkei/Markit survey that said factories had shed jobs at the fastest pace since the survey began in 2011.
The grim outlook for the second quarter pointed out to a sluggish full-year growth, analysts said. The median estimate for full-year growth was at 4.9 percent according to a recent Reuters poll, well below the 5.3 percent they had forecast at the last poll in April.
"Full-year GDP growth may even be lower if we don't see any improvement in the pace of fiscal spending going forward," Gundy Cahyadi, an economist with DBS, said.
The central bank has said it will be cautious over using interest rate cuts to support growth, as it has to assess the impact on the exchange rate, inflation and expectations that U.S. interest rates will rise.
A central bank official has said Bank Indonesia will have room to cut its key rate, which has been kept at 7.50 percent since February, once the Federal Reserves ends the uncertainty in global markets by raising rates.