Westerbeke 5.0MCG

450rdawg

New Member
May 9, 2021
21
Boat Info
330 Sundancer 1995
Engines
Twin 454 Mercruiser V-drive
Anyone else ever have an issue with the oil pressure light coming on with these? Runs for about 30 seconds and shuts down. It has plenty of oil. I pulled the filler lid from the valve cover and it’s pumping plenty of oil. Not sure what the issue is. Maybe the sending unit? Any help is appreciated.
 
If you hold the prime switch on it should stay running, if that is the case your low oil pressure switch or circuit could be bad. Holding the prime button will bypass that circuit. The low oil pressure switch is separate from the oil pressure sender. But in the same general location.
 
Along the same lines with that Generator, what are the steps to search/tweek to calm the "hunting" when it's under load?
 
Along the same lines with that Generator, what are the steps to search/tweek to calm the "hunting" when it's under load?

On my 340 I found low oil in the governor impacted the hunting/rpm control. Check and change your governor oil...it's quite easy.

EDIT - this is assuming you have a mechanical governor. Mine was a '99...far older than yours :)
 
If you hold the prime switch on it should stay running, if that is the case your low oil pressure switch or circuit could be bad. Holding the prime button will bypass that circuit. The low oil pressure switch is separate from the oil pressure sender. But in the same general location.
Not to sound ignorant but where would I find that switch? This isn’t the one the boat came with, it’s an updated, EFI version from the late 20teens.
 
Not to sound ignorant but where would I find that switch? This isn’t the one the boat came with, it’s an updated, EFI version from the late 20teens.

Ah, that changes things a bit. But it still should have the low oil pressure switch. I am not familiar with that version, but would think it still is near the oil pressure sender. The senders/switches are still the same. They just are connected to a wire harness and ultimately a PCB that handles the alarms and such.

Here's a manual that should be close to what you have: https://www.westerbeke.com/technical manual/55743 rev 0.pdf

Take a look at page 45, it looks like it is located at the base of the oil filter housing on the right side.

For this model, it could just be the wire(s) are off.
 
On my 340 I found low oil in the governor impacted the hunting/rpm control. Check and change your governor oil...it's quite easy.

EDIT - this is assuming you have a mechanical governor. Mine was a '99...far older than yours :)

It is mechanical (2000) and I was planning on changing the governor oil. I doubt it's been done in its 460 hours. Looks like I have to take it off to get to the drain and fill plugs, correct?

How would the oil have gotten low? Looks bulletproof to me. I have the 4.5KW BCBG.
 
It is mechanical (2000) and I was planning on changing the governor oil. I doubt it's been done in its 460 hours. Looks like I have to take it off to get to the drain and fill plugs, correct?

How would the oil have gotten low? Looks bulletproof to me. I have the 4.5KW BCBG.

I don't think you should have to remove it. On my 99 the fill was on top, the drain on the back, both accessible.

I discovered not long after mine started running erratically that my drain plug had completely fallen out (I had never serviced it, it was my first year of ownership). Hence why in the photo below there's an oddly sized drain plug installed - it's the best I could do in a pinch.


upload_2023-3-8_12-23-59.png
 
I don't think you should have to remove it. On my 99 the fill was on top, the drain on the back, both accessible.

I discovered not long after mine started running erratically that my drain plug had completely fallen out (I had never serviced it, it was my first year of ownership). Hence why in the photo below there's an oddly sized drain plug installed - it's the best I could do in a pinch.


View attachment 141028
Thanks. Mine seemed to be a bit tighter than that. I poked around when I was changing the oil and concluded removal to change the Governor oil may be easiest. I'll look again this weekend. Did the fresh oil stop the "hunting"? It does stabilize when I hold down the priming switch.
 
Thanks. Mine seemed to be a bit tighter than that. I poked around when I was changing the oil and concluded removal to change the Governor oil may be easiest. I'll look again this weekend. Did the fresh oil stop the "hunting"? It does stabilize when I hold down the priming switch.

Is the drain plug an Allen Wrench?
 
Thanks. Mine seemed to be a bit tighter than that. I poked around when I was changing the oil and concluded removal to change the Governor oil may be easiest. I'll look again this weekend. Did the fresh oil stop the "hunting"? It does stabilize when I hold down the priming switch.

When I plugged my drain hole and filled her back up with oil she ran like a champ.

I never found the drain plug but I would assume it may have had an allen/hex head. The fill screw was...
 
I don't think you should have to remove it. On my 99 the fill was on top, the drain on the back, both accessible.

I discovered not long after mine started running erratically that my drain plug had completely fallen out (I had never serviced it, it was my first year of ownership). Hence why in the photo below there's an oddly sized drain plug installed - it's the best I could do in a pinch.


View attachment 141028

On mine, the drain plug is on the bottom, the "fill to" overflow hole is in the back and the fill hole is on the top.
 
Is it this guy right here?
 

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On mine, the drain plug is on the bottom, the "fill to" overflow hole is in the back and the fill hole is on the top.

I think I may have had the same now that you mention it. Hence why mine continued to run but became erratic - is was spitting oil out the back but not fully drained. Makes sense.
 
Found out that the EFI units have an electronic governor.

Replaced the sensor, didn’t fix it. Found out that the sending unit was most likely my next option. It was very rusty and one of the terminals broke off when I touched it. When that happened the “ext alarm” light came on. I replaced the sending unit and can’t get that light to go off. Attached is a pic of the sending unit, also a pic of the codes/reasons behind the light being on. It’s almost like there should be a reset button on here but I haven’t been able to verify that. If any of you have any suggestions, I’d greatly appreciate any input.
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