Kirk RX3002001

Hello, great site. I have a 2001 RX300 AWD, std engine. Bought it new for about $37,000. It has 115,000 miles. When I bought it my dealer suggested using Prolong additive in my oil. After a while they stopped carrying it, but I kept putting it in religiously, and had a mechanic friend who swore by it. and I still do. At 90,000 miles my engine began to have a whining noise, I thought it was the alternator, so did they. After four days at the dealer, they discovered it was my oil pump th...