| Author |
Message |
    
ryan lindsey
New member
Username: rlind
Post Number: 1
Registered: 06-2009
| | Posted on Monday, June 22, 2009 - 11:32 am: | 
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Hi, I am new to these type of motors. Here the oil psi at different rpms. At full throtle the oil pressure is 40psi, at 3000rpms it is at 38psi, at 2000rpms it is 30psi, at 1200rpms the oil pressure is 28psi and at 600rpms it is 10psi. Does this look ok? I am concern about the low pressure at idle. This is when the engine is warm. Thanks so much for any input. |
El Pescador
Senior Member
Username: el_pescador
Post Number: 4525
Registered: 02-2006
| | Posted on Monday, June 22, 2009 - 12:19 pm: |
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It definitely looks low. First I would make sure that the oil grade is what it should be (I believe it is DuraPlus W30 for your engine) and the pressure gauge readings are accurate. If OK, I would change the oil and see if there is an improvement. |
ryan lindsey
New member
Username: rlind
Post Number: 2
Registered: 06-2009
| | Posted on Monday, June 22, 2009 - 12:26 pm: |
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I just changed the oil a couple of days ago to 15w-50. I believe i can use sae 30w, 20w-50 or 15w-50. Would 30 sae be better than 15w-50? Thanks El Pescador! |
El Pescador
Senior Member
Username: el_pescador
Post Number: 4526
Registered: 02-2006
| | Posted on Monday, June 22, 2009 - 12:42 pm: |
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I would definitely give it a try, since you are experiencing problems with your current oil grade. Also, make sure it is synthetic oil. |
Mike
Advanced Member
Username: mike77cj
Post Number: 358
Registered: 06-2007
| | Posted on Monday, June 22, 2009 - 12:50 pm: |
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10 pounds at idle seems a bit low in my opinion. It is normal for the pressure to fluctuate over the RPM band. Generally, I like to see 30-35 pounds at idle and 60-70 pounds on the backside of the rpm band.
As engines age bearings wear and oil pressure drops. I have seen engines with only 5 pounds at idle and 20 at speed last for many years. Unless you want to pull the engine and do an overhaul, I would just continue to maintain it and run it. |
ryan lindsey
New member
Username: rlind
Post Number: 3
Registered: 06-2009
| | Posted on Monday, June 22, 2009 - 12:51 pm: |
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I do use synthetic. EL pescador, do you know what the oil psi is supposed to be at idle and at wot? |
ryan lindsey
Member
Username: rlind
Post Number: 4
Registered: 06-2009
| | Posted on Monday, June 22, 2009 - 12:58 pm: |
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Thanks Mike, do you know the factory spec for the 5.7l oil pressure. |
michael cashman
Member
Username: michael_cashman
Post Number: 31
Registered: 04-2009
| | Posted on Monday, June 22, 2009 - 09:17 pm: |
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Hi Ryan, I have that same motor in one of my boats, great little motor, however it should be producing about 30 to 40 pounds at idle, no lower than 30 when warmed up, how many hours are on your engine? It may be time to consider an overhaul? unless you are willing to take the chance of getting out, and having no return one of these days, good luck with your boat.
mike |
ryan lindsey
Member
Username: rlind
Post Number: 5
Registered: 06-2009
| | Posted on Tuesday, June 23, 2009 - 07:56 am: |
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"Hi Ryan, I have that same motor in one of my boats, great little motor, however it should be producing about 30 to 40 pounds at idle, no lower than 30 when warmed up, how many hours are on your engine? It may be time to consider an overhaul? unless you are willing to take the chance of getting out, and having no return one of these days, good luck with your boat.
mike""
Mike, what is your oil psi at full throttle? I start the boat up today and let it run for 20 minutes attached to a hose and brought it up to temp. The engine was running at idle at 35 psi. I am really confused. The other day when I had it in the water, the psi at full was 42psi and then i brought to an idle and it was around 10-15 psi. I am go to switch oil today to a sae30 |
Robert A. Fierro
Advanced Member
Username: sandkicker
Post Number: 616
Registered: 06-2008
| | Posted on Tuesday, June 23, 2009 - 10:43 am: |
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The "rule of thumb" from my "performance car days" was... 10 psi per 1000 RPM minimum. |
michael cashman
Member
Username: michael_cashman
Post Number: 32
Registered: 04-2009
| | Posted on Tuesday, June 23, 2009 - 10:13 pm: |
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Ryan,
Good call on the oil switch!That is the oil your engine was made to run, and Ryan I am not sure of the wide open oil pressure in my boat, last time I hit w.o.t. it kind of scared the hell out of me, so I run her at around 3500 rpm for the most part, and at that r.p.m. I am getting about55 to 60 as per my gauge, I think its rather accurate? but who knows?
Ryan does your boat have a manual gauge, meaning it has a tube line feeding to the gauge itself, or is it electric, feed by two wires? if feed by two wires, I would consider making a trip to your local auto shop and spending around 20 for a manual guage, they tend to tell the truth a bit better than electric, and with any luck you will find that that thing has been pulling your leg all this time. My fingers are crossed for you, good luck.
Mike |
