Low Oil pressure at idle.

MrKav

Cadet
Joined
May 16, 2023
Messages
8
Hi all
New here.
I was told this is where to get all the right information.
So, I have 2 VP Kad44. 570 hours.
The other day after a beautiful trip, I was on my way in to the docks.
I lowered the rpm and saw that the oil pressure on one engine dropped and the alarm went off. I upped the rpm and the alarm stoped.
To day I tried to start up.
On cold engine I have around 20psi and 60psi on the “good” engine.
I have tried to change the oil pressure sensors from one engine to the other. Still low on the “bad” engine.
Then I changed the oil and filter. Still no change in pressure.
I am now lost for ideas what to do next.
Any comments or hints are welcome.
Hope the above makes sense :)
 

flashback

Captain
Joined
Jun 28, 2002
Messages
3,746
Get a stand alone pressure gauge and see what the pressure is.. maybe a sensor went south..
 

MrKav

Cadet
Joined
May 16, 2023
Messages
8
Thank you for your reply.
I have already tried the sensor from the working engine. Same result.
 

flashback

Captain
Joined
Jun 28, 2002
Messages
3,746
In that case sit tight, I'm a novice especially with diesel. Good folk here who can help with the electrics.. oil pump would be just a guess, they don't fail often
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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47,790
the things that impact oil pressure:

  • oil viscosity and temperature
  • oil pump volume and bearing clearances
  • oil pump regulator spring

of the 3, make sure you have good oil of the proper viscosity. if that doesnt work, pull the motor and get to the oil pump and bearings to check the last two.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,319
Hi. I’m afraid it sounds as if it may be a genuine fault. If both the oil pressure switch alarm sensor and the gauge are both indicating low.
Any sign of blue smoke out the back ? What’s the oil like ? Is it thin and smells of diesel perhaps?
The turbo might be suspect for its oil bearing seal failing. So too would the oil cooler. These would be best case. Worst case would be engine failure. Check your oil and coolant tank for any sign of issue. Get a gauge on her too. Did you swap over both oil senders ? The switch and the gauge ? How is the wiring to them ? Locally and at the dash.
 

MrKav

Cadet
Joined
May 16, 2023
Messages
8
No blue smoke.
No overheating
No noises
No discolor in oil
No diesel smell
No abnormalities in coolant
Turbos both changed
Only swapped over the pressure to the gauge.
Where is the oil cooler ?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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47,790
the shell and tube oil cooler is on the side of the block
 

MrKav

Cadet
Joined
May 16, 2023
Messages
8
The shell?
Can u ad a picture.
I have been told by a Volvo Penta mechanic, to look for 2 springloaded valves near the oil filter. One could be stuck in the open position. Therefore low pressure.
Sounds reasonable??
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,790
it could be possible that one of the oil control check valves is stuck. however that will require access from underneath the engine to get to the check valve. you will most likely need to pull the motor to get to it.

do your own research and google KAD44 oil cooler. it is a simple shell and tube heat exchanger. there are a few tear-down videos that pop-up.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,319
The shell?
Can u ad a picture.
I have been told by a Volvo Penta mechanic, to look for 2 springloaded valves near the oil filter. One could be stuck in the open position. Therefore low pressure.
Sounds reasonable??
That would be the filter bypass, he is likely referring to. Not sure he is on the right track with that one.
Is there any sign of oil in the water out the back ? Oil in the bilge ? Have a good look around the bilge if you can. Is there perhaps damage to the wiring to both the gauge and alarm pressure switches?
 

MrKav

Cadet
Joined
May 16, 2023
Messages
8
Hi again.
Been away for the weekend. Not sailing 😳
I have got this from a Penta mechanic to day.
He told me to look at this. See picture.
The two parts marked in read.
 

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MrKav

Cadet
Joined
May 16, 2023
Messages
8
No oil but where is supposed to be.
No damage to wires.
Had a manual pressure test on it also.
Confirmed around 20psi in idle.
I can maintain normal pressure (60psi) in neutral with 1500 rpm’s.
 

MrKav

Cadet
Joined
May 16, 2023
Messages
8
No oil but were it is supposed to be.
No damage to wires.
Had a manual pressure test on it also.
Confirmed around 20psi in idle.
I can maintain normal pressure (60psi) in neutral with 1500 rpm’s.
 
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