High Oil Pressure

I have a 2004Sea Ray 185 Sport with the 4.3L Merc. I am experiencing high oil pressure. I constantly get 85 -90 PSI at 3000 RPMs. I thought at first it was an instrumentation problem and I hooked up a guage straight to the block (where the sending unit attaches) and got the same reading. I also thought it might be a defective filter (I replaced the oil and filter when I winterized it) and so I put a new filter on but got the same elevated PSI. I'm hoping someone out there has experienced the same thing (and fixed it). Someone told me it might be a defective or clogged relief valve....is this valve part of the oil pump or in the same general area? I assume you have to pull the engine to reach this valve if that's the problem.

Re: High Oil Pressure

Ayuh,... Is this happening on a stone cold motor, or after it's well up to operating temps,..??

Re: High Oil Pressure

Along with Bond-o's question, did it JUST start? Or has it done it since new?

Re: High Oil Pressure

I would temporarily install a mechanical gauge and verify you have high oil pressure and not an electrical gauge or sender problem.

Re: High Oil Pressure

The problem started this year after i de-winterized it. It ran at about 60 psi since I've owned the boat. I'm running 25-40 (Merc recommended) in the engine. I spoke to a Merc tech and he said it couldn't be the relief valve but I'm at a total loss to what it can be if it's not that. The engine only has 160 hrs on it and I verified through a mech gauge that the oil pressure is running 80+ psi at 3000 RPMs after it's warmed up

Re: High Oil Pressure

and I verified through a mech gauge that the oil pressure is running 80+ psi at 3000 RPMs after it's warmed up

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Ayuh,... Is that warmed to temp on the muffs, or run hard up to temp, in the lake,..??

Re: High Oil Pressure

Has there been any work done on the engine lately? Before this happened.

Re: High Oil Pressure

No work has been done on the engine except i replaced the impeller and thermostat a month ago - i don't see how they can be related. The high PSI is noticed at idle on the muffs (40 psi) and on the lake under a load (80+ psi)

Re: High Oil Pressure

I think your mechanic is wrong. An oil pressure relief valve should be constantly dynamic, in other words bleeding the appropriate pressure according to the rpm of the motor. It could be sludged up or deformed ie stuck. Not good as it will wash the bearings rather than letting the oil lubricate. I've seen this issue in several types of motors both forign and domestic. I had a Lotus motor that would push nearly 120 psi at 8200 rpm then the valve would dump open and pressure went to zero. Look at those valves!

Re: High Oil Pressure

The Merc Tech is Half right. It can not be the OIL FILTER Bypass. This only bypasses the filter element if the difference in pressure from one side to the other is greater than a few psi (I think 7) but it does not RELIEVE pressure. A blocked filter would not cause high readings anyhow. the pressure port is AFTER the filter. The relief valve in the oil pump body should not let warm oil pressure get above the specified spring pressure. It is either stuck partially closed or blocked. The way this oil system is designed, even if the oil galleys are completely blocked, it should have the capacity to relive enough oil that it should never get above 60 or so PSI if functioning properly.