High Oil Pressure on 4-108 Perkins

[brakauskas]

Hi have a Perkins 4-108 on an Endeavour 40 25,000 pound sailboat. At 2200 rpm i have max speed of 6 knots with the oil pressure at 80lbs. I have talked to other Perkins owners and they see 6 knots at 1800 rpm and oil pressure at 50-60 lbs. Any suggestions?

[Maddog]

I'm not sure I would worry about the rpm's. I have a 4-107 and I average around 60 lbs at any speed. There might be a slight dip at idle, I'll check next time I'm out. 2200 is the top of the torque curve for that motor. I know that it is not unusual to run these motors at 1800 for their entire lives. 80 lbs seems high to me. Start with the simple things and trouble shoot the gauge and sender, then move on from there.

[brakauskas]

Just got off the phone with Transatlantic diesel and they said try OIl then Sender and gauge then the last fix would be a high pressure relief vavle in the oil pump. Hopefully it is just a gauge. What oil should be used for a Perkins on Lake Michigan?

[Jesse]

Delo 15-40 works well for me. It's a heavy duty all season oil that isn't expensive or hard to find.

[Ex-Calif]

Has it always been 80?

The manual says 50-65 lbs. The adjustment is on the right side below the dipstick.

What was the outside temperature and oil temperature. Cold oil is more viscous and will run higher pressure until it heats up.

If the pressure gauge drops at idle and runs up at speed I would not suspect the indicating system beyond cleaning connections.

[brakauskas]

WHat adjustment are you talking about? I have seen it go from about 60 to 80 under speed. I also see the guage start at 0 for about 8 seconds then it goes up to 60.

[Dynamo1181]

Screw a manual gauge in the block for accurate pressure/gauge check. I did and found the sender had gone bad. If you use a remote kit for the oil filter make darn sure you dont reverse the oil lines!
A

[shakey doug]

Do not undo that bolt, it holds the oil pump in situ ,4108 oil pump relief valves are not adjustable.

[Laidback]

Generally speaking oil pressure does not alter by increasing RPM - the reading of 80psi is probably too high. Using the correct viscosity lubricant (eg SAE 40 or a multigrade SAE 30>>50) should produce the spec psi, 40<>60 psi.

The gauge is probably over reading. If causing concern, install a new one.

[Mark Zarley]

I don't see 80 lbs as an issue. The oil is just being circulated at a higher rate . What is the history of the eng oil pressure? Has it always been this high or is it something new? Using a cheap mech guage (water pressure guage for a well system) from the hardware to verfiy the pressure would be easy .