[C320-list] Oil Pressure warning /// Check to see if the oil pressure sending switch metal tabs have broken

[Rick Sulewski]

Colin, 

I have a Westerbeke engine and when that same condition begins I have found
that the lead wires to the oil pressure sender switch located on the engine
with two lead wires attached has either a loose, or broken lead.  Usually
one of the tabs is broken and the vibration of the engine causes the
intermittent alarm or light condition. You can visually inspect and pull off
the leads from the switch to see if one of the metal tabs is broken. If so,
then you can get by for a short time and avoid the annoying alarm (if and
when the tabs no longer have contact with the switch) by simply connecting
the two leads together and by pass the sender switch by placing one of the
broken tabs or a wire splice between the two leads and tape those together
until you install a replacement oil pressure sender switch.  The metal tabs
usually break on my engine due to the vibration and metal fatigue every so
often until I attached a "softer" wire at the end of each of the original
wire leads so the vibration was not transferred from the engine to the
stiffer wires attached to the switch.

May want to remove the switch and take it with you to an auto replacement
parts store to see if they have a similar replacement switch, or buy the
real deal at 4-5 times that cost.

Hope this explanation serves you well.

Rick # 277

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Colin Evans
Sent: Saturday, February 19, 2011 12:34 AM
To: C320-List at Catalina320.com
Subject: [C320-list] Oil Pressure warning

 I have a 2000 model Yanmar 3GM30F.  When I start the engine the oil
pressure alarm and light come on as they are supposed to. However when the
boat has been motoring for 20 minutes or so and I put the throttle back to
idle the alarm sounds, but not a full alarm, sort of intermittent and the
light flickers.
I have changed the engine oil which was 6 months old, probably 40 hours,
thinking it may be getting too thin when hot.  I have run the engine in the
pen to working temperature at fast revs, then back to idle , but no alarm.
Any thoughts as to whether this is an electrical problem or do I have low
oil pressure.
 
************************************
Regards
Colin Evans
#774  Lake Macquarie, Australia