High Oil Pressure

DockHoliday · Aug 30, 2003

I have twin 2001 Volvo 5.0 GXi motors with 39 hours on each. I believe that they are both filled with 30W Dino (but I am not really sure). The manual calls for 30W Syn (Volvo brand).

I recently changed the Port engine to Amsoil 15W40 Marine/Diesel oil and Amsoil Filter. The oil pressure at cruise (3K-4K RPM) used to be around 60, but the Port is now aroound 80 after switching to the Amsoil. The starboard continues to be run around 60 PSI at cruise. The manual says that the high end of oil pressure range is 70.

Should I be concerned by the oil pressure reading 80?
Is this pressure diff due to the oil or the filter?
Should I consider switching to a thinner oil, such as Mobil 1 10W30?.

Your thoughts, comments, recommendatons, etc. are appreciated.

[ August 31, 2003, 01:21 PM: Message edited by: DockHoliday ]

JonS · Aug 31, 2003

I would think it is the filter. I have a 5.0 liter Ford in my boat. It runs (after warmup) 60 psi at 3000 rpms for cruising. I have experimented with different oils and filters, and have found that the filter seems to be restrictive sometimes. I found the Wix and Pure1 to show the highest pressure. I now use a Motorcraft FL-1a. I don't think you can use this on a Chevy. I really doubt it is the oil. I have found if i use a higher vis oil (40w), it gets hotter than a 30w and thus the same vis at a given temp, only hotter. Why don't you use the same oil in both motors?+
BTW, i now use Pennzoil 30w and used to use Delo 400 30w. The Pennzoil 30w seems sticky and thicker. I like it.

Steve S · Aug 31, 2003

Is one motor newer or are the gauges or senders off in their readings the oil pump could have different clearances all sorts of stuff could be different. You could have 20 of the same engines and the oil pressure will vary due to manufacturing TOLERANCES. Probably not worth worrying about unless the pressure gets high enough to burst the oil filter..

Hirev · Aug 31, 2003

Is this when the oil is good and warm? The oil sounds ok to me. I have a Bayliner with a Volvo. My guess is it is in the oil filter. It might not be the right one. It sounds like a pressure relief problem. 20 psi is a big jump.

userfriendly · Aug 31, 2003

Doc;
Several of the SBCs I have built run at 63 PSI hot with the high volume oil pump.
The Chevs have a filter by-pass that opens at around 10 psi. Be careful not to over-tighten your filters and break the pot-metal mounting thingie.
The Fram part number for the extra long filter is PH373, you could cross that number over to an AC number or something else if you suspect the filter is at fault.
Those filters are about a foot long and may not fit in your hull space.
Take a look at the post I started in the question of the day film strength/thickness.
If your pressure is up due to a viscosity change, that indicates that the flow is down.
Do you want high oil flow or high pressure?
I thought you were on the right track with your 5W40 or SAE 30 initial choice.
Some 15W40s are very close to 20W50s.
For some reason people like to see high oil pressure.
The race pumps I sometimes use put out over 80 psi in a SBC and maintain that pressure with hot SAE 30 engine oil.
The oil flow in and out of the bearings is high in this case, because the pump was enlarged instead of the lubricant viscosity increased.
The rule is 10 lbs for every 1000RPM for your engine design.
At 4500 RPM you have a 15lb safety margin at 60 lbs.
I trust you got your fuel lines re-routed and batteries changed out.
I'll be lookin' for a good used OB 115-150 HP 2 stroke long shaft next spring.
Quite often I notice a person can get the entire boat n' motor cheaper than just the used motor.

DockHoliday · Aug 31, 2003

Both engines are the same age (new boat last fall).

I changed one engine, but hated the oil pump so much, that I post poned the other engine until I acquired a better pump (long story).

I am considering changing the oil on the other engine, but using a different filter. This should help narrow things down a bit. Or, I might stick with the Amsoil filter and use Mobil 1 10W30.

userfriendly - The batteries are fine now, and the fuel line has been fine until recently. I started to get a power drop again which I assume is fuel starvation. I will have the dealer work on this over the winter (under warranty).

userfriendly · Aug 31, 2003

Your loosing me here.
I'll assume you boat cost $75,000.00
The boat is 10 months old, and you have had 39 hours of use from it or about $2,000.00 per hour.
You have replaced engine number one already.
Engine number two has a different oil pump.
Engine number one has SAE 30 oil and an AC filter
Engine number two has AMSoil 15W40 and an AMS filter
You have replaced the batteries already.
Engine #1 was losing power until a pinched fuel line was discovered.
What was your question again?

[ September 01, 2003, 03:03 AM: Message edited by: userfriendly ]

wulimaster · Aug 31, 2003

quote:

Originally posted by DockHoliday:
I have twin 2001 Volvo 5.0 GXi motors with 39 hours on each. I believe that they are both filled with 30W Dino (but I am not really sure). The manual calls for 30W Syn (Volvo brand).

I recently changed the Port engine to Amsoil 15W40 Marine/Diesel oil and Amsoil Filter. The oil pressure at cruise (3K-4K RPM) used to be around 60, but the Port is now aroound 80 after switching to the Amsoil. The starboard continues to be run around 60 PSI at cruise. The manual says that the high end of oil pressure range is 70.

Should I be concerned by the oil pressure reading 80?
Is this pressure diff due to the oil or the filter?
Should I consider switching to a thinner oil, such as Mobil 1 10W30?.

Your thoughts, comments, recommendatons, etc. are appreciated.

For maximum protection and performance I would go with the series 3000 5w30 Amsoil.

I vote for the filter causing the restiction.

DockHoliday · Aug 31, 2003

quote:

Originally posted by userfriendly:
Your loosing me here.
......
What was your question again?

quote:

Originally posted by userfriendly:
Your loosing me here.
I'll assume you boat cost $75,000.00
The boat is 10 months old, and you have had 39 hours of use from it or about $2,000.00 per hour.

We spend most of the time anchored, not cruising. Thus, while the engines have only run 39 hours, we have spent much more time than that on the boat. Also, the 39 was a typo, the engines have 59 hours. I chose the Amsoil because of the anti-corrosion package since the engines are not run that much. Also, I like to amortize the cost of the boat over much more than one season.

quote:

Originally posted by userfriendly:

You have replaced engine number one already.
Engine number two has a different oil pump.
Engine number one has SAE 30 oil and an AC filter
Engine number two has AMSoil 15W40 and an AMS filter

I changed the OIL and FILTER in one engine (with AMSoil 15W40 and an AMS filter), still have the other to do (conventional oil, OMC filter). Otherwise, both engines are 100% original.

quote:

Originally posted by userfriendly:
You have replaced the batteries already.
Engine #1 was losing power until a pinched fuel line was discovered.

You asked about my fuel lines and batteries. I assumed you saw my posts on Boating ABC, so I gave you an update.
Yes, I had problems with the batteries. Long story, turns out the connections were not good to the batteries. I replaced all of the batts just to be safe, no more problems.

One of the fuel lines was cut too short at the factory. As a result, it turned to tight of a corner, and would "kink" like a garden hose. I will have this fixed under warranty over the winter.

quote:

Originally posted by userfriendly:

What was your question again?

My question was is the oil or the filter causing the increase in oil pressure.

wulimaster - I have 6 qts of the 2000 0W30 in the garage and have been considering using that. I really like the idea of a lower wt oil at start up since the engines often go 5 days or more between starts. But I also like the idea of the anti-corrosion additives in the marine oil.

wulimaster · Sep 1, 2003

quote:

Originally posted by DockHoliday:

wulimaster - I have 6 qts of the 2000 0W30 in the garage and have been considering using that. I really like the idea of a lower wt oil at start up since the engines often go 5 days or more between starts. But I also like the idea of the anti-corrosion additives in the marine oil. [/QB]

Amsoil usage sheet says that you can use that but the preferred lightweight oil is the 5w30 Series 3000. All Amsoil oils contain rust inhibitors.

DockHoliday · Sep 1, 2003

wuli - I was not aware of that oil, and thought your original post was a typo. Thanks for the recommendation. I might just go with that oil.

Mike_dup1 · Sep 1, 2003

fyi

Amsoil has an SAE 30 synthetic diesel oil, API SH,SJ

I don't know if it would be approiate for use in the your engines but its sounds like it could be?

Here a quote from their info PAGE .

quote:

In personal cars and light trucks with non-turbocharged gasoline engines and marine craft: drain oil at intervals up to two times as long as those recommended by the engine manufacturer or at six-month intervals, whichever comes first.

Recommended for applications requiring the following specifications:

API Service CF, CF-2, CG-4, CH-4, SH, SJ
ACEA/CCMC D4, PD2
MIL-L-2104F
Caterpillar Powershift Trans. TO-2 and TO-3
Allison C-3 and C-4
Mack EO-L, EO-M
M.A.N. 270
Mercedes-Benz AG 227.0, 228.0
Scania Long Drain
Volvo VDS
VW 505.00

[ September 01, 2003, 06:41 PM: Message edited by: Mike ]

Steve S · Sep 1, 2003

Also thicker oil will give higher oil pressure all things close to equal.

I would run the 15w/40 in both engines.

[ September 01, 2003, 09:59 PM: Message edited by: Steve S ]

DockHoliday · Sep 2, 2003

Here is my plan: I now have a Fram oil filter that I will swap with the Amsoil filter. I will then test the oil pressure (on a fully warm engine) to see if that drops the oil pressure down to 60 at 3K-4K RPM. If it does, then I go with Fram filters and Amsoil 15W40 on both motors.

If the above does not bring about the desired oil pressure, then I will put the Amsoil filter back on, then change the oil in the other engine with Mobil 1 10W30. At this point I will have the option of using the Fram Filter or a new Amsoil filter. Hmm, the Fram will already be full of Amsoil, is this a factor? I can pour out most of the oil in the filter.

Your thoughts are greatly appreciated.

Steve S · Sep 4, 2003

You would be better off with 15w/40 . Boat engines can use the extra protection when under load . Ever notice boat engines do not last as long as auto engines.

DockHoliday · Sep 15, 2003

I ended up purchasing a Volvo OEM filter from a VP dealer, and swapped that for the Amsoil filter. The pressure did go down across the RPM range, probably about 3-5 PSI. The Port motor still has higher oil pressure than the Starboard, especially at idle. Thus, I don't think the filters are causing the high oil pressure.

I am going to change the other motor to the same oil (since I already have it in the garage), put the boat away for the winter, and reconsider next spring. I will probably try the Amsoil Series 3000 5W30.

Steve S · Sep 16, 2003

If it were my boat I would want the higher oil pressure in the other engine.

High Oil Pressure

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