Oil pressure alarm

[jscardam]

I have a 1990 Hunter 30T with 2 cyl Yanmar Diesel inboard. At the end of last season I performed the routine oil change and ever since there is a significant delay in the timing that that oil pressure alarm triggers once the engine is killed.

Previously, the alarm went on almost immediately after the engine stopped. Since the last oil change, the alram takes 10 to 15 seconds to go on after engine stops?

Should I be concerned? Any comments would be appreciated.

 

[centerline]

it wouldnt concern me, as long as it does work... the old oil was contaminated.... this it normal and the reason it needs to be changed periodically. and because of the contamination it was probably a lot thinner when it was warm... now you have clean oil in the engine which is much more stabile in viscosity, so now it does not escape the tiny pinhole in the sensor as quick.

 

[Ralph Johnstone]

Since the last oil change, the alram takes 10 to 15 seconds to go on after engine stops?

I assume your oil temperature is hot. Mine does the same until the temp. is up and the viscosity is down.

 

[Allan12210]

You could remove the oil sender and clean it with a bit of solvent. Its probably gunked up. Otherwise it's fairly inexpensive to replace.

 

[Ilanortho]

Got tired of driving around with only warning lights; installing engine gauge panel from ACDC Marine for Yanmar 3GM30. Meant also putting a fuel gauge sender in the tank (also tired of guessing the fuel level), which also meant now able to scrub out the tank, which also meant new hoses which also meant a Raycor fuel centrifugal filter which also meant a new fuel cutoff valve, and also meant has an engine hour (Hobb) meter and an oil pressure sender and temp sender and a water temp gauge..................Oh Hell! Just shoot me.

 

[Ilanortho]

Oops, almost forgot: replaced the panel's electric cutoff switch with a new SeaStar Solutions cable in its place on the gauge panel; the old cable could no longer be lubed anymore and required two hands to pull out.

 

[Benny17441]

Oil pressure just drops gradually after engine shutdown; with the time interval of time to trigger the sensor being mostly dependent on the viscosity of the oil. The higher the viscosity, the longer the time interval. The only thing I would be concerned of is why the old oil got so thin that it would trigger the alarm seemingly much quicker than the new oil. High temperatures will thin an oil out so any comparison between the old and new oil should be performed at similar ambient temperatures and engine running conditions. Was the oil replaced with the same gauge of oil it had before? Also the age of the old oil is significant as it will gradually loose viscosity from heat and contaminants. (for this reason after an engine suffers an overheat the oil should be promptly changed). Now a quickly thinning oil could be the signs of a worn out engine, restricted air intake or a faulty mechanical fuel lift pump which could be leaking diesel fuel into the cranckcase. I would be concerned if the oil lost significant viscosity within 90 days of the last change date but otherwise I would not worry.

 

[Charles Erwin]

Does this delay happen if you immediately stop the motor at cold start up or only when you stop the motor after it is fully warmed up?
Does the warning lamp/alarm extinguish promptly at motor startup? Is there any difference in time to lamp extinguishment if the motor is started from cold or started at normal operating temperature?
Did you change the oil brand/type from prior oil changes? What brand, weight, and type did you use?
Did you measure the amount of oil you put in the motor?
Have you monitored the oil stick level since your oil change? Has it changed?
Did you change the oil filter?
What brand and part number filter?

Charles