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jcasper

Anyone know marine diesels? Cummins QSC 8.3 ??

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Just got a call from my Father-in-law. He is on his way North to Alaska in his boat. Boat has a Cummins QSC 8.3 Engine might have 6-800 hours on it. His oil pressure is higher then normal today. Sitting at 77 PSi, generally is in the 60-70 range at cruising speed. What might cause this? Filter issue?

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Is it a mechanical gauge or electric? I would change the filter regardless as it is easy to do.

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Is it a mechanical gauge or electric? I would change the filter regardless as it is easy to do.

Electric. The mechanical gauge says the same.

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Well, the next question is, where is the sensor located (before the filter or after) in the circuit?

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Well, the next question is, where is the sensor located (before the filter or after) in the circuit?

I have no idea. The boat is just north of Campbell River right now.

 

Maybe I should take a float plane and go look. Haha.

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Let me know if you want me to tag along. LOL!

 

Change the filter for sure and see if there is an change. Look at the bright side, higher pressure is better than low.

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Let me know if you want me to tag along. LOL!

 

Change the filter for sure and see if there is an change. Look at the bright side, higher pressure is better than low.

That's what I thought. I told him Low would be more of a concern.

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Oil pressure sensor is in the main oil rifle after the filter. Would not hurt to change the filter and see what happens like Ben stated. 77PSI is really not that high for oil pressure.

 

Sent from my SM-G900R4 using Tapatalk

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What about engine coolant temp? If the engine is running cooler the oil would be cooler causing the pressure to rise.

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What about engine coolant temp? If the engine is running cooler the oil would be cooler causing the pressure to rise.

Engine was at 166* at this time. They had been under way for 30 minutes when I talked to him.

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Is that normal temp? Single screw or twin?

He says that is normal. Single.

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He talked to some guy at Cummins today. Told him to shut off and restart. He did and gauge showed more normal. In the 65 area.

 

They are next day airing him a new pressure sensor and he is changing the filter. Mechanical gauge on the engine showed high also so. So Im not sure what this is accomplishing.

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The new sensor he is getting may be a on/off switch. I know they update the pressure sensors on the ISC so that when the engine has oil pressure, the gauge reads 55PSI until the pressure drops enough to open the switch and then the pressure will read 0.

 

Sent from my SM-G900R4 using Tapatalk

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Diesel mechanic says he has a high pressure relief valve causing some issues, it has a broken spring. New one is on the way from Memphis.

 

Mechanic said the oil pressure should be in the 75 range however but he never had seen that high before.

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