My guess in order of probability:

1.) The oil pressure sender needs cleaning and/or replacing, or has a loose or worn wire. 

2.) There is a problem with the computer

3.) The oil pump needs to be replaced

4.) Main bearings worn

I am betting it is number 1. 

BTW, I don't believe that this applies to you, but there is a known issue with a Yanmar that causes an indication of low pressure...there is a "T" that the oil pressure sender screws into. This "T" is known to get clogged and cause low pressure. 

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

   

On Jul 1, 2017 03:33, "mshirloo@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

Hi everyone;

We left Kythera this morning to head to Crete. About 15 minutes out of Kythera we had sufficient wind so we backed out the engine RPMs from about 1500 to Idle to shut off the engine. We immediately got a low oil pressure warning and a message to shut down the engine. Having had check engine faults before that per the suggestions in the manual  would go away after turning the engine off and then back on again, we tried this with the low oil pressure warning. We got the same warning again. So we shut down the engine and sailed back to our anchorage that we had just left and dropped anchor again. After waiting about 10 more minutes and having reviewed the Volvo manual, we turned the engine on again. We did not have the warning. We then placed the engine in reverse and reved up to 1400 RPMs 4 separate times for about 30 seconds, as if we were setting the anchor. The issue did not reappear.

We decide d to head out, having good favorable winds. We sailed for about 1 hour before the wind started to die down and we started the engine and started motor sailing. After 30 minutes the wind came back up again so we decided to turn off the engine. When we lowered the RPMs to idle, the low pressure warning light came on again. So we have shutoff the engine and are now sailing with about 7 hours left to Crete. The forecast is for the wind to die down when we get close to,our harbor and we will probably need to motor sail the last couple of hours.

I checked the engine oil before we started me again after we received the warning. The oil and oil filter were changed about 1 month ago with genuine Volvo parts about a month ago. I have not looked through the manuals or done any research yet, since I wanted to,get this post out before we lost connection. If any one knows the location of the oil pressure sensor, I'd appreciate the info since it may just be a loose electrical connection. All ideas and suggestions would be appreciated.

Mohammad & Aty

B&B Kokomo

Amel 54 #099