Diesels love their oil like a sailor likes his rum.

[Jim Hawkins]

Couldn't resist that line from the movie, Captain Ron.
So, I'm working on a boat with a Westerbeke Universal M-35B. The PO had no issues with the motor. When the new owner started the engine for the first time it fired up and ran very nice but we noticed the oil pressure gauge was at zero. I think it's likely the gauge is not working but don't want to run the motor any until we can confirm oil is circulating. Although I'm a decent mechanic on all things gasoline, diesel confounds me, no experience. All those funny hoses and boxes that do I don't know what. So needless to say I'm looking for 2 things. 1, how to know if oil is circulating and if so how to check the gauge.
Thanks

 

[DayDreamer41]

I don't have any experience with a Westerbeke, but I did sleep at a Holiday Inn Express last night......
There should be a oil pressure switch as well as a gauge, if the idiot light isn't coming on I would think that you would be good. My bet would be on the oil pressure sending unit, which can be replaced for <$100 attached is an example....

Sierra 23-5880 Oil Pressure Sender For Westerbeke

Shop Wholesale Marine for Sierra Marine 23-5880 Oil Pressure Sender. Wholesale Marine offers the largest selection of marine engine parts at best prices.

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[Rich Stidger]

It could also be a broken/corroded wire between the sensor and the gauge. If you T/S this to be a bad sender, check this out:

Used gear for sale

Used gear for sale

sbo.sailboatowners.com

Attached is a T/S procedure to determine the problem. It works on all typical USA standard brands of gauges. Checks the gauge and wiring. For sure you don't want to run the engine until you are certain that the oil is circulating. You do have oil in the engine, don't you?

 

[jssailem]

Starting and stopping the engine then looking under the oil cap will tell in a second if you have oil circulating. Or you can be bold and disconnect one of the oil hoses or loosen the oil filter. Oil flying out is a dead giveaway that you have oil under pressure.


The most likely suspect is the sending wire to the gauge. You can check the gauge with your digital volt meter.

 

[Jim Hawkins]

Rich, John, thank you. Good ideas.
After considerable time looking, by the time I found the dipstick I was beginning to feel like one.
Yes there is oil, but it looks yucky. I thought it would be good to run the engine a little each week, even with old oil, than to let it sit. The wiring on the gauges look pristine, all the more so when you consider the shape of the rest of the boat. I traced an orange wire back to the sending unit. I hope that unit isn't bad as it looks a bugger to get to.

 

[Davidasailor26]

there is oil, but it looks yucky

What kind of yucky? Black would be normal diesel yucky. Milky or otherwise discolored could be worse news.

 

[Jim Hawkins]

What kind of yucky? Black would be normal diesel yucky. Milky or otherwise discolored could be worse news.

It didn't look like normal black oil but it didn't look like oil I've seen with water either. I need a closer look. How do you change the oil in these things, with a pump?

 

[Davidasailor26]

How do you change the oil in these things, with a pump?

Probably, yes. We had a Universal M-12 that had a hose connected to the bottom of the pan. We’d hook the extractor pump to that to suck the oil out. Our current Yanmar doesn’t have that hose so we use a tube down the dipstick hole for the pump.