Generator low oil pressure shutdown here in the Caribbean

[davethedog]

Hi all, and yes this is a real first world problem!

We have a Mastervolt Whisper 3500 generator fitted (was on the boat when we bought her in the Uk) and now finding that after a few hours of running it will sometimes shut down and give a "low oil pressure" warning on the display. The oil level is checked and all good and we never had this issue in the UK before we left. I have changed the oil pressure sender today and it ran for about 80 mins then gave the same error. Have just cleaned out a small amount of stuff from the water intake filter and changed the impeller (the old one looked fine to me but changed it anyway) and removed the engine side case and opened the engine bay and has been running for about 2 hours so far. Obviously running it with the case off ands the engine bay open is not ideal!

Would this be due to the increased water temperature here making the oil too thin?

If so, would changing the oil viscosity to a thicker oil help? Current oil is Multigrade 15/40.

Apologies if this seems a stupid question but when I have been in places around the world using 4x4s etc they usually have a different oil than in say the UK.

DTD

 

[jwfrary]

I would start with the wiring to be honest, follow the connections back to the diesel digital control box and remake and tighten any connections.

You could also check the oil pressure with a seperate gauge. If thats fine then you know its electrical.

You could also use a resistor to fool the electronics into believing the system has oil pressure, but you will want to verify it manually first or risk engine damage

Could something have got in the sump and be blocking the pick up pipe partially?

How many hours are we talking about on this unit, they do have relatively short ish lives.

 

[geem]

Hi all, and yes this is a real first world problem!

We have a Mastervolt Whisper 3500 generator fitted (was on the boat when we bought her in the Uk) and now finding that after a few hours of running it will sometimes shut down and give a "low oil pressure" warning on the display. The oil level is checked and all good and we never had this issue in the UK before we left. I have changed the oil pressure sender today and it ran for about 80 mins then gave the same error. Have just cleaned out a small amount of stuff from the water intake filter and changed the impeller (the old one looked fine to me but changed it anyway) and removed the engine side case and opened the engine bay and has been running for about 2 hours so far. Obviously running it with the case off ands the engine bay open is not ideal!

Would this be due to the increased water temperature here making the oil too thin?

If so, would changing the oil viscosity to a thicker oil help? Current oil is Multigrade 15/40.

Apologies if this seems a stupid question but when I have been in places around the world using 4x4s etc they usually have a different oil than in say the UK.

DTD

I would be very surprised if this was a oil grade issue. Its not particularly hot in the Caribbean at the moment. We run 15/40 in ours with no problems. Where are you in the Caribbean?

 

[jwfrary]

Could be poor heat x performance leading to high oil temps, is it the one that's essentially just oil cooled and then the raw waters injected in the exhaust? Or do you have jacket water?

 

[davethedog]

I would be very surprised if this was a oil grade issue. Its not particularly hot in the Caribbean at the moment. We run 15/40 in ours with no problems. Where are you in the Caribbean?

Antigua at the moment

 

[davethedog]

I would start with the wiring to be honest, follow the connections back to the diesel digital control box and remake and tighten any connections.

You could also check the oil pressure with a seperate gauge. If thats fine then you know its electrical.

You could also use a resistor to fool the electronics into believing the system has oil pressure, but you will want to verify it manually first or risk engine damage

Could something have got in the sump and be blocking the pick up pipe partially?

How many hours are we talking about on this unit, they do have relatively short ish lives.

In total about 700hrs

 

[geem]

Antigua at the moment

Where? We are at Green Island

 

[davethedog]

Where? We are at Green Island

currently in jolly harbour at anchor, looking to head to Barbuda thu.

 

[geem]

currently in jolly harbour at anchor, looking to head to Barbuda thu.

Might see you there. Similar plans. Look out for yacht Wild Bird?

 

[davethedog]

Could be poor heat x performance leading to high oil temps, is it the one that's essentially just oil cooled and then the raw waters injected in the exhaust? Or do you have jacket water?

No idea!

 

[Beneteau381]

Hi all, and yes this is a real first world problem!

We have a Mastervolt Whisper 3500 generator fitted (was on the boat when we bought her in the Uk) and now finding that after a few hours of running it will sometimes shut down and give a "low oil pressure" warning on the display. The oil level is checked and all good and we never had this issue in the UK before we left. I have changed the oil pressure sender today and it ran for about 80 mins then gave the same error. Have just cleaned out a small amount of stuff from the water intake filter and changed the impeller (the old one looked fine to me but changed it anyway) and removed the engine side case and opened the engine bay and has been running for about 2 hours so far. Obviously running it with the case off ands the engine bay open is not ideal!

Would this be due to the increased water temperature here making the oil too thin?

If so, would changing the oil viscosity to a thicker oil help? Current oil is Multigrade 15/40.

Apologies if this seems a stupid question but when I have been in places around the world using 4x4s etc they usually have a different oil than in say the UK.

DTD

If it continues to run with the engine "doors" open then it is a temp issue. Not necessarily the oil viscosity, unless you have diesel getting in to the oil?

 

[Skylark]

May or may not be relevant as I have no experience of boat generators but in the car world it’s not uncommon to have an oil pressure sender failure.

 

[jwfrary]

No idea!

Can you post a photo so we can properly identify it.

Have you ever cleaned the heat exchanger?

You have changed out the sender for the oil pressure.

700 is fairly low hours wise so I wouldn't expect you to have worn anything out, but that's not impossible.

I think you need to verify the pressure is good, but I suspect if you have a good sensor then you may be over heating just slightly and that's what's causing it to run without the covers on but when the covers go back on you get a shutdown.

That's how I read it!?

 

[stranded]

From our experience with a similar problem on the same generator and the advice of a number of engineers, I suspect you may find the problem is a sensor rather than what the display is telling you is wrong. Problem is, you cannot be sure which sensor, because they are daisychained and the displayed fault code is merely the machines best guess what the problem is. You would need to test each sensor in turn by bridging them out of the circuit, but some are not simply on or off so bridging them won’t work. And if it gets worse, you may reach the point where the engine will cut out within seconds and cannot be made to run long enough to conduct tests and after several years and a lot of cash you will get fed up chasing serial problems and get a new generator. I am just about to order a Honda suitcase because the (what became) the Whisper 3.5 is no longer available and nothing else will fit in our space. Sad thing is that the actual engine works perfectly and has never missed a beat unless told to by the dodgy electronics.

I hope your experience is happier, but if you search online you will find that ours is a long long way from being a unique story.

 

[geem]

From our experience with a similar problem on the same generator and the advice of a number of engineers, I suspect you may find the problem is a sensor rather than what the display is telling you is wrong. Problem is, you cannot be sure which sensor, because they are daisychained and the displayed fault code is merely the machines best guess what the problem is. You would need to test each sensor in turn by bridging them out of the circuit, but some are not simply on or off so bridging them won’t work. And if it gets worse, you may reach the point where the engine will cut out within seconds and cannot be made to run long enough to conduct tests and after several years and a lot of cash you will get fed up chasing serial problems and get a new generator. I am just about to order a Honda suitcase because the (what became) the Whisper 3.5 is no longer available and nothing else will fit in our space. Sad thing is that the actual engine works perfectly and has never missed a beat unless told to by the dodgy electronics.

I hope your experience is happier, but if you search online you will find that ours is a long long way from being a unique story.

That makes sense. My own Perkins generator has the water temperature sensor and oil pressure sensor daisychained so you don't know which has triggered a shutdown. It always the water temperature though as so many more causes. Blocked heat exchanger, failed impeller, blocked inlet pipe, blocked exhaust elbow, failed fresh water pump, low fresh water level, failed water pump belt, etc

 

[davethedog]

Thanks all and will keep playing with it, ran it last night for over 2 hours with the shell closed and the engine bay doors shut, after changing the oil (which was only 20 hours use}). We have spare sensors so let's see.

Will see about cleaning the oil heat exchbager (if there is one) but it does not mention anything about that in the manual etc

 

[Aja]

Hi all, and yes this is a real first world problem!

We have a Mastervolt Whisper 3500 generator fitted (was on the boat when we bought her in the Uk) and now finding that after a few hours of running it will sometimes shut down and give a "low oil pressure" warning on the display. The oil level is checked and all good and we never had this issue in the UK before we left. I have changed the oil pressure sender today and it ran for about 80 mins then gave the same error. Have just cleaned out a small amount of stuff from the water intake filter and changed the impeller (the old one looked fine to me but changed it anyway) and removed the engine side case and opened the engine bay and has been running for about 2 hours so far. Obviously running it with the case off ands the engine bay open is not ideal!

Would this be due to the increased water temperature here making the oil too thin?

If so, would changing the oil viscosity to a thicker oil help? Current oil is Multigrade 15/40.

Apologies if this seems a stupid question but when I have been in places around the world using 4x4s etc they usually have a different oil than in say the UK.

DTD

Would it be possible to fit an oil cooler, if there isn't one already there?

 

[geem]

Would it be possible to fit an oil cooler, if there isn't one already there?

We don't have an oil cooler on ours. I would be surprised if the OP was the first person to use that make of generator in a warm climate. It shouldn't need modification to run in 28degC ambient air temperature.
Definitely worth exploring the temperature side first before looking at the oil issue

 

[stranded]

Ours would show oil temp immediately after starting after not being used for days - ambient was c.10c I should think - definitely wasn’t the oil temp. If we tried and tried it would occasionally not show that but within a very few more seconds show “frequency” and shut down anyway. Reading around other fora persuaded us any solution was likely to be short lived so have decided to stop throwing money at it. Not an easy decision as I don’t like deck operated generators but with plenty of solar we should only need to run it for a hour or so every few days and maybe when at sea with all instruments.

 

[geem]

Ours would show oil temp immediately after starting after not being used for days - ambient was c.10c I should think - definitely wasn’t the oil temp. If we tried and tried it would occasionally not show that but within a very few more seconds show “frequency” and shut down anyway. Reading around other fora persuaded us any solution was likely to be short lived so have decided to stop throwing money at it. Not an easy decision as I don’t like deck operated generators but with plenty of solar we should only need to run it for a hour or so every few days and maybe when at sea with all instruments.

We have a super simple 27 year old twin cylinder Perkins. No electronics. No AVR. Simple fail safe water and oil pressure sensors on a common shut down circuit. That's as complicated as it gets.
It's fuel efficient and reliable except for the raw water pump that is always needing seals and bearings. I carry a spare pump ready to fit then rebuild the old one