Oily pressure on the decrease

[LL 1975]

Canaline 52HP

Can any one think why my engine which runs at between 1 and 2 oil pressure (standard canaline panel) after about an hour slightly loses oil pressure (dropping down to around 1 ) which causes the oil pressure alarm to sound? Funnily enough increasing revs with the engine out of gear at this point increases the pressure and stops the alarm sounding. However bring the throttle back at any time after this and the pressure drops again and the alarm sounds. Oil level looks fine. Recently changed the oil sender which didn’t change anything. 

[ditchcrawler]

What oil are you using?

[LL 1975]

4 minutes ago, ditchcrawler said:

What oil are you using?

The correct non synthetic one - reason I’m so confident is I checked with Engines Plus to get the right one and had to order it delivered by new era to get the right one in large quantity (25 litres so I don’t faff around next time). 

[dmr]

How many hours has this engine done and has it been regularly serviced etc (if you know) ?

Does it sound ok or any nasty knocking sounds?

[LL 1975]

8 minutes ago, dmr said:

How many hours has this engine done and has it been regularly serviced etc (if you know) ?

Does it sound ok or any nasty knocking sounds?

Hours around 2000, good service history around once a year after initial 50 hours. Not sure about oil filter mind you, oil was def changed in the last 3 services.

[nicknorman]

You have done the sensible first step which is to replace the oil pressure sender. So it sounds as though the pressure is actually low, rather than it being an indication issue.

As dmr implies, low oil pressure can be caused by worn crankshaft bearings but it may be something less serious than that, such as a sticking oil pressure relief valve. Have you changed the oil and filter recently? A blocked oil filter is another (though rather remote) possibility. Is the coolant temperature normal, and adequately filled (very hot oil can cause low pressure)?

 

Maybe eliminate any doubt by getting the actual oil pressure checked with a mechanical gauge screwed into where the oil pressure sender goes. If that shows low oil pressure then check the pressure relief valve.

[dmr]

3 minutes ago, LL 1975 said:

Hours around 2000, good service history around once a year after initial 50 hours. Not sure about oil filter mind you, oil was def changed in the last 3 services.

 

Do you get the low oil pressure when cruising/battery charging (with a few revs on) or just at tickover?

[MtB]

9 minutes ago, LL 1975 said:

Hours around 2000

 

This is still a young engine so one wouldn't expect to get low oil pressure, even at tickover. What make and model of engine is it exactly? 

 

 

31 minutes ago, LL 1975 said:

The correct non synthetic one - reason I’m so confident is I checked with Engines Plus to get the right one

 

I note you swerved the question! What oil is this, exactly?

 

 

[PCSB]

If it helps the correct oil spec is API CC or CD specification. Either 10W/40, 10W/30 or 15w/40. This is from the canaline service manual.

[Quattrodave]

2 hours ago, LL 1975 said:

Can any one think why my engine which runs at between 1 and 2 oil pressure.

 

Errr what scale are you measuring oil pressure in?

 

My first thought is the oil is being 'watered down' I'd guess with diesel, has the oil level gone up with out adding oil??

Edited November 15, 2023 by Quattrodave

[john.k]

probably in "Bar".....ie about 14 1/2 psi per unit.........first thing Id check is diesel in the oil .....simple test is dip a finger,spread the oil out and smell it .......15psi ,while a bit low isnt going to kill an engine PROVIDED there is no turbocharger.

[blackrose]

10 hours ago, LL 1975 said:

Canaline 52HP

Can any one think why my engine which runs at between 1 and 2 oil pressure (standard canaline panel) after about an hour slightly loses oil pressure (dropping down to around 1 ) which causes the oil pressure alarm to sound? 

 

Your oil pressure will drop slightly as the engine warms up because the viscosity of the hot oil decreases resulting in reduced oil pressure. That also happens on my Isuzu 55 and I understand it's normal.

 

Why your oil pressure alarm goes off I'm not sure, but if you're using the correct viscosity oil and the oil level is correct then the first thing you need to determine is whether the oil pressure sensor is operating properly. 

 

When I start my engine and it's idling the oil pressure alarm goes off and I have to rev it a bit out of gear to stop the alarm. When I put it back to idling the alarm no longer sounds. Perhaps your alarm sounding at low revs is something similar and it's just out of calibration?

Edited November 15, 2023 by blackrose

[magnetman]

Someone reported diesel getting into the oil on the same engine.

 

 

 

"Update on the diesel in oil problem. I removed the lift pump from the engine block, keeping the fuel lines attached i repeatedly pressed the plunger in on the back of the pump and guess what ......... diesel poured out from around the plunger! So there's the problem!"

 

 

 

 

 

Apparently the Canaline 52 is a Kioti diesel engine. 

[Tracy D'arth]

Oil pressure switches generally open at over 5psi, but they are not accurate. If yours is closed at 1 bar, 15psi, either it is an odd one, faulty, or the wrong one. I suggest you ask the engine supplier because 1 bar on a newish engine is not good, I would of expected at least 20psi at tick-over hot.