High Oil Pressure

[lawrence_craig]

Hey guys,

Just a quick point in the right direction for my Volvo D2-55D;

My oil pressure goes from 2.5 bar at 1500 revs to over 5 bar at 1550 revs, what does this suggest?

Many thanks

[a64pilot]

It’s normal for pressure to increase with RPM, but to double with only 50 RPM is a big jump. I’d suspect a sticking gauge or sender. With any oil pressure issues I think verifying the problem with a direct pressure reading gauge to be the place to start.
Sometimes it’s just the gauge

[adenduyf]

I’ve got the same problem with a CAT D330 which has been diagnosed as a stuck oil pressure relief valve. Biggest risk seems to be the potential of blowing the oil filter gasket which would not be good!

[Lepke]

AS a64pilot says - it's a good idea to have a mechanical gauge in your spares for checking at the engine. But 5 bar isn't excessive for modern engines. I use to build racing engines and ran those at above 100psi.

[Wotname]

Originally Posted by lawrence_craig

Hey guys,

Just a quick point in the right direction for my Volvo D2-55D;

My oil pressure goes from 2.5 bar at 1500 revs to over 5 bar at 1550 revs, what does this suggest?

Many thanks

My first suggestion would be to check the service manual for the engine to determine the setting point of the high pressure relief valve (I don't have a manual for this engine).

Depending on the numbers, you might or might not have a problem.

If the high pressure relief valve is meant to be less than 5 bar, then the above posts suggest some very good starting points - especially checking the real pressure by way of a mechanical gauge as others have posted.

BTW, has it always behaved this way or is this something new?

[GordMay]

Greetings and welcome aboard the CF, adenduyf.

[DougR]

From the D-55 service manual:
- oil pressure- (hot engine at running speed) 22psi to 73 psi - 1.5 to 5 bar
- oil pressure- idling 7 to 22 psi. - .5 to 1.5 bar

- oil pressure relief valve opening- 35 to 50 psi. - 2.5 to 3.5 bar
( note- Perkins 404c manual calls for 3.5 to 4.5 bar for relief valve opening)


As others have mentioned, a manual gauge should be used to get a better view of the buildup of pressure vs. RPM. Your actual pressure is good.....5 bar is right where it should be, so probably you have a sticky pressure sender or gauge.

Should everything point to a stuck pressure relief valve, you can remove the valve and check it for blockage or other abnormalities. It is located in the oil gallery on the starboard side of the engine 6 or 7" ahead of the oil filter.

DougR

[lawrence_craig]

Originally Posted by DougR

From the D-55 service manual:

- oil pressure- (hot engine at running speed) 22psi to 73 psi - 1.5 to 5 bar

- oil pressure- idling 7 to 22 psi. - .5 to 1.5 bar



- oil pressure relief valve opening- 35 to 50 psi. - 2.5 to 3.5 bar

( note- Perkins 404c manual calls for 3.5 to 4.5 bar for relief valve opening)





As others have mentioned, a manual gauge should be used to get a better view of the buildup of pressure vs. RPM. Your actual pressure is good.....5 bar is right where it should be, so probably you have a sticky pressure sender or gauge.



Should everything point to a stuck pressure relief valve, you can remove the valve and check it for blockage or other abnormalities. It is located in the oil gallery on the starboard side of the engine 6 or 7" ahead of the oil filter.



DougR

Great stuff, thank you. I will check it out.

It’s only happened in the last week or so.

Interestingly it’s now jumping to 5+ bar above 1400rpm and 2.5 bar at 1300rpm so sounds if the problem is worsening. Will check it out shortly

[keepondancin]

I had the reverse problem, lost oil pressure. Confirmed no pressure with a gauge. Changed oil filter, and have pressure. Start easy and cheap

[Compass790]

Originally Posted by keepondancin

I had the reverse problem, lost oil pressure. Confirmed no pressure with a gauge. Changed oil filter, and have pressure. Start easy and cheap

Just curious. Do you know how many hours your filters did before they caused the loss of oil pressure?
Very unusual for oil filters not to have a bypass valve these days.
What is your oil pressure now with the new filter installed?

[keepondancin]

Less than 10. My pressure guage shows about 55 psi. Telling the story to knowledgeable people, most have said they have heard of that happening. I use NAPA Gold. The Napa store said I should have cut it open. I wouldn't have known what I was looking at, never opened a filter up.

[Compass790]

Originally Posted by keepondancin

Less than 10. My pressure guage shows about 55 psi. Telling the story to knowledgeable people, most have said they have heard of that happening. I use NAPA Gold. The Napa store said I should have cut it open. I wouldn't have known what I was looking at, never opened a filter up.

Thanks for posting your experience. I've never heard of it & very surprised it could happen. The Napa gold filters I have are fitted with a bypass valve to prevent that sort of thing happening. Part no. 1773
It's not your responsibility to cut the filter open it's theirs' I would have thought. Only way that could happen is if bypass valve is faulty unless the filter
isnt fitted with one.
You can look up your oil filter part no on their website & check to see if it has a bypass valve. Mind you it's lucky you caught it as if the filter clogged after 10hrs & the bypass valve opened for the rest of the time before you changed it the engine would be running on unfiltered oil.
Very interesting experience.

[Wotname]

Originally Posted by Compass790

Thanks for posting your experience. I've never heard of it & very surprised it could happen. The Napa gold filters I have are fitted with a bypass valve to prevent that sort of thing happening. Part no. 1773
It's not your responsibility to cut the filter open it's theirs' I would have thought. Only way that could happen is if bypass valve is faulty unless the filter
isnt fitted with one.
You can look up your oil filter part no on their website & check to see if it has a bypass valve. Mind you it's lucky you caught it as if the filter clogged after 10hrs & the bypass valve opened for the rest of the time before you changed it the engine would be running on unfiltered oil.
Very interesting experience.

Yes, curious indeed. If the filter was truly clogged after 10 hours, I would be very concerned with whatever clogged it and from what of the engine did the material come from?

However it may have been a faulty filter(?????).

I would be changing the new filter after a few hours and cutting it open - looking for any material in it (especially metallic material). The correct amount should be none

What engine was it and how old (years or hours)?