Volvo low oil pressure alarm

[bchristie]

I am the new owner of a 2014 Cutwater 26 with the Volvo D3 220 hp engine; 270 hours TT. I got a low oil pressure alarm today when running at about 3000 rpm. Oil pressure indicated 38 psi. No alarm indication at 1500 or lower rpm. I recently had the engine oil changed and it is now about one quart over the full mark on the dipstick. Could this have caused the alarm? I know high oil level can cause the oil to emulsify and not pump properly. Any suggestions will be appreciated. Also, where is the oil pressure sending unit located on these D3 engines? Thanks in advance!

 

[BB marine]

Oil pressure sending unit is located between oil dip stick and heat exchanger. Lower portion of the block. A Low oil pressure alarm should also be followed with reduced power. If at 3000rpm and oil alarm sounds do you experience reduced power? Yes ,it is a true no or low oil pressure warning alarm . No, possibly a bad sensor. I would not rule out high oil level causing the alarm. I'm not sure why though. You do not want to run the engine with oil 1 quart over full. The recommended oil level for a D3 in the C26 is in between the add and full mark on the dip stick. There are multiple warnings in the owners manual and shop manual (Be sure not to over fill the engine) Lower oil level to proper level. Sea trial again and see if that resolved issue.

 

[bchristie]

Thanks for the input. Yes, the engine did go to reduced power, (1500 rpm I think) when the low oil pressure alarm activated, I will pump out the excess oil and see if that corrects the problem.

 

[bchristie]

More on low oil pressure alarm: The oil was overfilled by about one quart. After removing the excess oil still having the low pressure alarm. When I started the engine cold the oil pressure indicated 68 psi but as oil warmed the pressure came down to 35 psi at 1500 rpm. I did sea trial the boat and there was no increase in pressure indication with increase in rpm. Got the low pressure alert at about 2300 rpm and 33 psi indicated. Any suggestions on next actions? Thanks!

 

[BB marine]

What viscosity oil are you using ?

This is from Volvo Manual
Possible reasons
• Too low engine oil level.
• Blocked oil filter.
• Engine oil contaminated or too thin (low viscosity)
• Faulty sensor.
• Faulty pressure reduction valve.
• Blocked oil suction pipe.
• Worn oil pump. Faulty pressure relief valve in the oil pump.


Solutions

1 Check the oil level in the engine. Be sure not to overfill the engine.
2 Check that no oil leakage occurs.
3 Check that the oil filter is not blocked by changing the oil filter. Change the oil.
Be sure not to overfill the engine.
4 Check the oil pressure with a manometer to verify the function of the sensor. Please, refer to “Lubrication system, Workshop manual Grp 20-26” where to connect the manometer.
5 Replace the pressure reduction valve located after the oil cooler. Please, refer to “Lubrication system, Workshop manual Grp 20-26”.
6 Check that the oil suction pipe isn’t blocked. Replace the oil pump. Please, refer to “Lubrication system, Workshop manual Grp 20-26”.



Step 4 - A pressure gauge can be installed where the oil sending unit is installed. The removal of the oil pressure sending unit is required. To remove the sending unit and sending unit adapter the dip stick needs to be removed first. You will have to match the threads of the sending unit adapter to a fitting that a gauge can be threaded into. Oil pressure ranges should be:

At start up 80psi
700 rpm after warmed up 51 to 65 psi
2000 rpm 65 to 80 psi
4000 rpm 80 psi to 94 psi
All pressures are with the oil temperature at normal running temperature



Step 5 -- Requires removing the oil cooler to get to the relief valve. The oil cooler unfortunately is in a tight spot on the oil pan starboard side. Removal of the after cooler will help gain access. I doubt it is the receive valve!

Hopefully it's a sending unit or wrong viscosity oil. Good luck troubleshooting. I would Check the oil filter installation. Replace with another one. Did this issue start after oil change? Oil viscosity needs to be 15W 40

 

[bchristie]

The oil and oil filter were changed about one hour engine time before this low oil pressure alarm event. The first test run after oil change had no alarm at engine speed up to about 3500 rpm. I did not note the actual oil pressure reading. The second run after oil change, I had been underway for about 20 minutes at low rpm. I powered up to about 3,000 rpm for a short time then went to wide open throttle. RPM increased to about 4,000 and within a about 20 seconds the low oil pressure alarm occurred with automatic throttle back to low rpm. So it appears something occured at the high rpm that triggered the low pressure. I will change the oil and filter as the next step. I very much appreciate the very knowledgeable input and help!