Low oil pressure alarm problem with Perkins 4108M

"I have a Perkins 1984 4.108M

"I have a Perkins 1984 4.108M with 4,500 hours. It has an audible low pressure alarm, I also recently fitted a visual mechanical oil pressure guage. Increasingly, as I throttle back into idle after motoring the low pressure alarm sounds, eg if anchoring - if I throttle up in neutral it stops sounding. Now the problem has worsened the alarm is sounding almost as soon as I start the engine even though the visual mech pressure guage indicates the pressure is acceptable, eng temp is also fine - any ideas what could be wrong or how to test?
Thanks."

If the visual guage shows that

If the visual guage shows that the oil pressure is normal then there is a fault with the alarm sensor. Replace it.

"I also have a 4-108. the low

"I also have a 4-108. the low pressure problems i encontered over the years were. 1- wrong grade of oil. I went from sae40 to 15-40 and the pressure dropped dangerously. Tropical climate. I went back to sae40 and solved the probleme. 2- the water pump is gear driven on mine and I had salt water leaking into the sump at a few occasion, caused by wear of seals on the shaft. That has caused the oil pressure relieve valve to corrode and stick, not moving freely. most be disambeled and polished.

try thicker oil, might solve your problem quickly. The drop of oil pressure when you idle the engine is normal but should resume quickly as the oil cools down.

good luck."

Just replaced the oil pressure

Just replaced the oil pressure alarm switch on my Perkins 4.108. Only $12 at Napa. Alarm system works fine now.