One problem related to oil pump has been reported for the 1999 Volvo S70. The most recently reported issues are listed below.
My Volvo 1999 S70 t5 has had problem with oil leaking (or burning) since the second year. My husband heard some strange and louder than normal noise from the engine and he checked the oil and no more oil in the engine. He had to put 3 to 4 quarts of engine oil in. This kind of incident happened at two times when my car was under 50,000 miles and under warranty. We reported to Volvo dealer services, they could found any problem the first time. Second time they found some problem and fixed it. Now at 51700 miles (out of warranty), we have the same problem again. My husband had to put 3 quarts of oil into the engine because there was no more oil left in it. This morning I noticed that the temperature was higher than normal. We called both Volvo of irvine, and cerritos of California and they denied that we reported any problem about oil in the past. Only Volvo of irvine saying that they did fix some problem with oil pump in the past because we complained about engine noise. They did not put it down about the complained of out of oil in the engine. We cannot trust Volvo services. Poor service and very bad Volvo car.