Boiling Panda

[jeremyshaw]

Anyone got some thoughts for a friend struggling with a boiling Fisher Panda genset in the Caribee.

He already knows that FP's are not considered the top of the class, so let's not go there. Here's the situation:

1. Looks like he has good raw water flow. The raw water is warming up as the genset starts then cools down as the stat opens.

2. After running for a while the coolant gradually heats up then starts to boil at around 150F.

3. He's changed the stat and the freshwater pump.

4. There appears to be poor flow from the pump and possible ingress of air.

My conclusion is that either he's got another duff pump, or there's an obstruction in the coolant system somewhere. However both seem unlikely given that coolant doesn't calcify, as far as I know, and the genset has not done massive hours.

He's having real trouble trying to find where the obstruction might be. Some have suggested a problem with the cylinder head gasket. Seems unlikely to me (and there's no contamination of the coolant, which has been renewed).

Any further thoughts?

Thanks

 

[Talbot]

sounds like a prevous owner had a cooling fan detach some pieces, and that these jam up the passageways when the engine revs up - I have that trouble with a car.

 

[rogerthebodger]

Fisher Panda use various makes/types of engine for their gelerator. Do you know which engine it is based on.

I have a generator (not FP) based on the farymann ,that I rebuilt earlier this year, which is the same engine FP use/used for their smallest generator.

 

[michael_w]

Bits of knackered impeller bunging up the heat exchanger? Would account for the poor raw water flow rate.

Little wrigglers taken up residence in the external seacock grille?

 

[jeremyshaw]

Thanks for the thoughts so far. Don't know the exact engine I'm afraid. To be clear the prob is NOT raw water flow which is good. It's coolant flow.

Here's the latest update:
"Blockage is most definitely between the CFW (coolant) pump and thermostat housing.
Not sure how I'll proceed now. I get just a trickle getting through once
I've isolated it to this point. Very difficult to pump. Hear lots of
gurgling sounds and a bit will spit out the thermostat housing side's hose
I've rigged. I'm pumping up into the pump right now. I assume the CFW pump
will allow flow without it needing to move."

Sounds like there's a blockage in the channels in the engine maybe?

 

[Aja]

Is the impeller actually working? Could it be that the body of the impeller has become detached from the spindle?

Donald

 

[jeremyshaw]

Thanks RogerShaw. The engine is a Kubota Z482.

 

[Talbot]

try removing the impellor pump, and thermostat housing and try waterpressure in the reverse direction to normal water flow (from a standard tap) see if you have decent flow, or whether it dislodges something.

 

[jeremyshaw]

Thanks Talbot, he's done or doing all that. Latest report is:

"I detached the belt and hand spun the CFW (coolant) pump in the proper direction with no
results there really. I don't believe the pump is blocking. If I pump air
and push as much fluid that is contained in the small section I'm focusing
on now it appears I get most the fluid out eventually. Then when I attempt
to pump fluid again it takes many pumps before the blockage begins. Since
the pump is right at the beginning you'd expect I'd feel blockage almost as
soon as I start pumping fluid. It doesn't. So there has to be blockage
somewhere around the engine's coolant jacket of channels."

Seems unlikely that more than one channel would block, and if only one did I would have thought you'd get local overheating, but overall the cooling system would keep control - or is that wrong?

Also could a problem with the head gasket cause this? I thought not as I reckoned you'd get oil contamination too, which is not happening, but maybe that's not so?

 

[Talbot]

That report does not sound as if they have tred to blow it back the other way. That may be the only way to clear it.

 

[jeremyshaw]

Good point Talbot. I think he's doing that but maybe I just assumed it. Will check. Thanks.