Help.
95 Ford Mustang 3.8 V6 recently purchased. I have a problem identifying a metal tapping noise heard only under certain circumstances. No noise when the car is in idle or driving normally. But if the car is in park and rev up the engine, I hear the rather loud metal tapping noise. Also hear it with fast starts from a dead stop and the rpms reach 2500 to 3000 before shifting. No noise until it hits this level. I tried a 5 min engine flush and oil change. When I turned the engine on right after this I heard the same noise but only for two seconds before the new oil recirculated. What is the problem? It is hard for me to isolate the noise. Is it bearings, valves, rockers, stems? I don't think it is the injectors or converters. Should I try a professional engine flush? Any additional additive to try?