Ken Boyd
Well-known member
- Joined
- Jun 2, 2011
- Messages
- 69
- Fluid Motion Model
- C-248 C
- Hull Identification Number
- 2517H809
- Vessel Name
- Kristi Marie
When I started breaking out my R-25 this spring from winter storage, I encountered a problem with my Cummins/MerCruiser QSD 2.0 engine that I had never encountered before with any other type of engine. I thought I would share it with the Tugnut community so other Cummins/MerCruiser owners who encounter the same problem will know the cause.
When I started the engine up to clear the antifreeze, the oil pressure was reading 0.6 psi and various low oil pressure engine alarms started going off. Since the engine did not sound like it was running without oil, I assumed I had an oil pressure sensor problem. I ordered a new sensor from Jamestown Distributors and swapped out the sensor but no improvement, still 0.6 psi of oil pressure. Further investigation revealed that very little engine oil was going up to the oil filter assembly where the oil pressure sensor is located, hence the low oil pressure reading. Since the engine was operating properly when I laid the boat up in December, I was a bit perplexed but a little relieved since it now appeared that I was dealing with a mechanical rather than an electronic problem.
My local MercCruiser dealer pled stupidity relative to anything diesel and could not even identify a MerCruiser dealer who knew how to service these engines. Cummins appears to have dropped this engine from their catalog though MerCruiser still lists it as an option in theirs (the Cummins/MerCruiser partnership dissolved a few years ago). I contacted MerCruiser through their website and they were able to identify a dealer about 100 miles away who could service the engine.
Before hauling the boat down to the dealer, I traced the oil pressure circuit in the engine's service manual and identified the engine's internal oil pressure regulation valve. Fortunately, it is accessible from outside of the engine so I took it out to make sure it was not sticking. While I had the oil pressure regulation valve out, I cranked the engine over a few times and oil started flowing up to the oil filter assembly. When I put everything back together, the engine worked properly and the oil pressure was back in the normal range. The problem appears to have been the engine's internal oil pressure regulation valve was stuck.
I hate to think about the ride an unscrupulous dealer could have taken me on with this relatively minor engine problem. If you know where to look, the fix will takes about 30 minutes since everything is out in the open. Hopefully if any other Cummins/MerCruiser QSD owners experience a similar problem, they can profit from my experience.
Please send me a PM if you need additional details.
When I started the engine up to clear the antifreeze, the oil pressure was reading 0.6 psi and various low oil pressure engine alarms started going off. Since the engine did not sound like it was running without oil, I assumed I had an oil pressure sensor problem. I ordered a new sensor from Jamestown Distributors and swapped out the sensor but no improvement, still 0.6 psi of oil pressure. Further investigation revealed that very little engine oil was going up to the oil filter assembly where the oil pressure sensor is located, hence the low oil pressure reading. Since the engine was operating properly when I laid the boat up in December, I was a bit perplexed but a little relieved since it now appeared that I was dealing with a mechanical rather than an electronic problem.
My local MercCruiser dealer pled stupidity relative to anything diesel and could not even identify a MerCruiser dealer who knew how to service these engines. Cummins appears to have dropped this engine from their catalog though MerCruiser still lists it as an option in theirs (the Cummins/MerCruiser partnership dissolved a few years ago). I contacted MerCruiser through their website and they were able to identify a dealer about 100 miles away who could service the engine.
Before hauling the boat down to the dealer, I traced the oil pressure circuit in the engine's service manual and identified the engine's internal oil pressure regulation valve. Fortunately, it is accessible from outside of the engine so I took it out to make sure it was not sticking. While I had the oil pressure regulation valve out, I cranked the engine over a few times and oil started flowing up to the oil filter assembly. When I put everything back together, the engine worked properly and the oil pressure was back in the normal range. The problem appears to have been the engine's internal oil pressure regulation valve was stuck.
I hate to think about the ride an unscrupulous dealer could have taken me on with this relatively minor engine problem. If you know where to look, the fix will takes about 30 minutes since everything is out in the open. Hopefully if any other Cummins/MerCruiser QSD owners experience a similar problem, they can profit from my experience.
Please send me a PM if you need additional details.