Generator Problem

IDAMAY

IDAMAY

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We have a Mastervolt Whisper 8 Generator on our Trader 42. The gennie operates OK for between 20 and 30 minutes before stopping with the error message "Failure Coolant Temperature." I have checked the following:

1. Raw water inlet filter clear and water running through skin fitting.
2. Impeller free and in perfect condition (new about 3 hours running ago).
3. Water appears to be running through exhaust - see through piping in engine room but can't verify exhaust water exit from hull as below waterline.

I would expect, if there was a blockage of some kind in the raw water system, it would cause failure earlier than this, especially with ambient water temp around 18C.

Has anyone ideas about what may be the cause and/or what further investigation I might undertake.

Many thanks.

Richard.
 
It's critical to know whether the genset is raw or fresh water cooled, and you don't say. I'm going to assume fresh water. In that case, the message likely refers to the jacket water not the raw. So you need to check (a) freshwater coolant level/leak, (b) jacket water coolant pump (drive belt?), (c) possible crud in the heat exchanger, and (d) maybe the temperature sensor
 
Many thanks, JFM. Yes, it's fresh water cooled and the coolant level is spot on. Drive belt OK. I suppose it's just possible that the water pump isn't working at its full capacity which leaves your (c) and (d) either of which is probably beyond my "engineering" capability! I may leave it until we are back in CI or UK (currently in south Brittany) as my French is only marginally superior to "engineering."
 
IDAMAY said:
Many thanks, JFM. Yes, it's fresh water cooled and the coolant level is spot on. Drive belt OK. I suppose it's just possible that the water pump isn't working at its full capacity which leaves your (c) and (d) either of which is probably beyond my "engineering" capability! I may leave it until we are back in CI or UK (currently in south Brittany) as my French is only marginally superior to "engineering."
Click to expand...

Ref item (c) , the heat exchanger is likely a cylinder the size of 2 coke cans stacked one atop the other. It likely has a lid held on by one nut/screw or something simple like that. Very easy to take apart and clean the insides. Sometimes you find broken off rubber impeller blades in there, from the raw water pump. Worth a try!
 
Many thanks again. I have now downloaded the User Manual from Mastervolt. I had the Installation Manual and the Remote Control Manual but not the really useful one. Anyway, I now know where the exchanger is, plus the thermostat and the thermal cut out - so a bit of progress! The exchanger likely hasn't been cleaned since new (2008) and I do know that at least one impeller didn't have much left when it was replaced so might now be residing there!
 
IDAMAY said:
Many thanks again. I have now downloaded the User Manual from Mastervolt. I had the Installation Manual and the Remote Control Manual but not the really useful one. Anyway, I now know where the exchanger is, plus the thermostat and the thermal cut out - so a bit of progress! The exchanger likely hasn't been cleaned since new (2008) and I do know that at least one impeller didn't have much left when it was replaced so might now be residing there!
Click to expand...

I think you are looking in the correct direction, check for bits of impellor in the heat exchanger, they will cause a gradual heat build up until the temp sensor shuts it all down.

Graham
 
What about the sensor itself? Have you tried changing that? Tend to agree with No Regrets though. It's always vital to remove every last chunk of failed impellor
 
Just to close off this saga, it turned out to be a combination of two problems:

1. The thermostat did not open at the correct temperature and

2. There was some c**p in the heat exchanger on the coolant side. This appeared to consist mainly of scaling.

There was no obvious sign of bits of impeller exiting from the sea water side of the exchanger.

Unfortunately the exchanger is not the type with a removable end cap so the above was only observed from flushing.

Anyway, we now have a functioning generator which we will need on the outer pontoons in St Peter Port on Sunday and probably in Salcombe later next week.

Richard.
 
Hi IDAMAY,

When the engine water temps on Play d'eau started to rise a few years back, I was advised to descale the heat exchangers. When I came to plan this, I found myself wondering if scale built up elsewhere in the engine/hoses and so on, with the obvious conclusion that it must.

So I devised the following method to clean out thr whole engine of lime scale: http://www.playdeau.com/descaling-the-heat-exchanger/

Here I must add that the idea was planted by finding a website that sowed the seed, so I can't claim full rights!

It worked a treat. Perfect.
 
Piers said:
Hi IDAMAY,

When the engine water temps on Play d'eau started to rise a few years back, I was advised to descale the heat exchangers. When I came to plan this, I found myself wondering if scale built up elsewhere in the engine/hoses and so on, with the obvious conclusion that it must.

So I devised the following method to clean out thr whole engine of lime scale: http://www.playdeau.com/descaling-the-heat-exchanger/

Here I must add that the idea was planted by finding a website that sowed the seed, so I can't claim full rights!

It worked a treat. Perfect.
Click to expand...


Piers,

No doubt a dumb question - apologies: why not remove impellor & pump electrically without running the engine?

John G
 
Hi Piers,

Thanks for the tip. As it happens I had the main engine heat exchangers and after coolers descaled as part of this year's service. I should have done the generator at the same time! Hopefully that will last a while but I will remember your method when the time comes. It also has the advantage of descaling the pipes and other parts not normally in reach.

We have booked into Beaucette for three nights from Monday (ETA around 09.00 after refueling at St Sampsons) so we will catch up with you assuming you are around.

Richard and Elvia
Trader 42 Ocean Star.
 
IDAMAY said:
Hi Piers,

Thanks for the tip. As it happens I had the main engine heat exchangers and after coolers descaled as part of this year's service. I should have done the generator at the same time! Hopefully that will last a while but I will remember your method when the time comes. It also has the advantage of descaling the pipes and other parts not normally in reach.

We have booked into Beaucette for three nights from Monday (ETA around 09.00 after refueling at St Sampsons) so we will catch up with you assuming you are around.

Richard and Elvia
Trader 42 Ocean Star.
Click to expand...

Hi Richard and Elvia,

Really looking forward to seeing you both again. We have one of our sons, his wife and two children staying with us. Do come around and knock - you'll see us at the bottom of the main ramp. See you soon.

Piers and Lin
 
Jegs said:
Piers,

No doubt a dumb question - apologies: why not remove impellor & pump electrically without running the engine?

John G
Click to expand...
I,d be very careful doing this -as the engine is not running it may have stopped with exhaust port / valve open .
If the " electric " pump ,s flow rate is too strong ,there is a risk of filling up the cylinder ( s) via overfilling the exhaust manifold .
That's an expensive error !

I conect a pipe to the closed seacock and flush it ( engine running -pumping correct flow ) with what ever - oxalic acid ,hydrochloride acid ,water and at winter lay up or prolonged inactivity - antifreeze - for rust inhibition .
 
Portofino said:
I,d be very careful doing this -as the engine is not running it may have stopped with exhaust port / valve open .
If the " electric " pump ,s flow rate is too strong ,there is a risk of filling up the cylinder ( s) via overfilling the exhaust manifold .
That's an expensive error !
Click to expand...
Yup good point I hadn't thought of that
 
Portofino said:
I,d be very careful doing this -as the engine is not running it may have stopped with exhaust port / valve open .
If the " electric " pump ,s flow rate is too strong ,there is a risk of filling up the cylinder ( s) via overfilling the exhaust manifold .
That's an expensive error !

I conect a pipe to the closed seacock and flush it ( engine running -pumping correct flow ) with what ever - oxalic acid ,hydrochloride acid ,water and at winter lay up or prolonged inactivity - antifreeze - for rust inhibition .
Click to expand...

Hi Portofino. I take the return to the Rydlyme tank from the hose that feeds into the exhaust which I believe overcomes the point you make.
 
Sorry to change subject slightly but still on Mastervolt.

I have a MV 3.5 whisper gennie,
Since a shutdown due to impeller failure (all pieces removed) I have had as many as seven attempts to start (each time stopping after ten seconds )before it will run correctly.
The failure displayed is coolant , does anyone know if this is the sensor on the cylinder head, or is there a thermal cut out lurking somewhere ?
Would any damage occur if I bridged any sensor to check.
 
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