Hey All,

I have an M104.980 engine that has strange oil pressure readings. After warmed up, it shows 2 at idle and climbs to 3 when revved = normal. When in gear and accelerating strongly it drops to 0-1 until I let off the accelerator. Also, when climbing hills it drops to 0 for several seconds until I let off the pedal.

Are there pressure valves that need to be cleaned (which ones and where?) or should I replace the oil pump? Car has had the oil pressure drop-upon-accelerating condition for many years. Installed new oil pressure sender last year = no difference. Also, there is a definite change in the sound and temps when climbing, so definite reduction in oil pressure, not a sending unit or gauge problem. THANKS!