Alarm buzzing on Lehman 4D61

[sshana1]

Last year the alarm buzzed but went off on 1984 Albin 27 FC and this year during first run the alarm continued
What is this buzzing and how can I tell if part needs to be replaced or if it indicates a problem with engine?
Thanks for all help

[tego]

The only alarm on most engines is the oil pressure alarm. Check the oil level ASAP. If it's ok, then confirm your engine oil pump is operational. If OK, it's probably the oil pressure sending unit. If you're not sure what I'm talking about, then call a diesel mechanic before you go out again. Ben

[sshana1]

Thanks for your response!!
It turns out ithe alarm is shot will need to replace it
Anyone know where I can purchase the unit?

[RobS]

What is shot? The pressure switch that is installed in the engine?

[jleonard]

Yes saying the alarm is shot is meaningless.
Two items will make the buzzer sound : low or no oil pressure and overheated coolant.
The oil pressure switch is normally closed and some oil pressure ( usually 15 psi) will open the switch and the alarm will stop. This sounds like what you are experiencing.
I would call ADC (American diesel corp) to make sure you get correct switch although they are pretty generic as long as the mounting threads match (I would guess 1/8 npt).

[DCatSea]

You might want to check clearance between top of oil filter and steel cooling line on the port side of the engine. My rather embarrassing oil alarm was the result of the cooling line rubbing the top off the filter mid-Bay. Oil flying around all over the show. Luckily wads of Gorilla Tape kept us mobile long enough to get alongside.

Simple fix was to extend the cooling line away from the oil filter by lengthening the coolant line so it wasn't rubbing.

Cooling pipe rerun.JPG

Point of something - photo was taken before this winter's engine room clean up - a bit nicer now.