8kw westerbeake generator losing water

[motion30]

Originally Posted by Seeking Solace

The UV dye will leave no room for doubt. UV dye can be found in any automotive store.

So i need the dye and a black light? Will the dye mark the inside of a hose?

[meridian28]

I have the same generator and same problem. New cap didn't fix it. When I go to start it after not using for a day or so the water will be down a pint or so, just enough for the sensor in the thermostat housing to cause a shut down. I add the water to the tank, fill the overflow container and it will run for 24+ hours without a problem. The next time I go to use it. the water will again be low and the overflow is empty. I haven't pulled the heat exchanger yet.

On a Ford Lehman with a 7# cap a failed heat exchanger will force sea water into the system and push it out the overflow bottle.

[jamhass]

PS:

Let us know what you find.

[yachtgemini]

We have the same generator and similar problems and yes it was the heat exchanger. Specifically, the end caps on both ends had become very weak and were not holding a seal. When it was tested the fault was not evident. When it was hot fresh was going into the sea water but as it cooled the end caps were sucking up tight and salt was not going back into the fresh side.

We replaced it with a new unit and had the same problem return a few years later. I then bought an oversized Bowman unit and mounted it off the genset and 10 years later have not had an anode to replace nor any problems. The Bowman was 1/3 the price of the Westerbeke.

Ross

[River Cruiser]

I also have a 8.0 Westerbeke and had the same problem and did all the things mentioned to no avail. I finally found the gasket between the end plate and the exhaust manifold was allowing coolant to be pushed out the exhaust by the residual pressure in the system. Some models of the 8.0 have a one piece manifold in this type this can't happen


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[jamhass]

I'he had very good luck sourcing after-market heat exchangers and oil coolers from Lenco:

Lenco Coolers - marine heat exchangers, marine oil coolers

They knew exactly what I needed for my engine, and delivered quickly. Easy to work with.

I'm just a happy customer.

[Squanderbucks]

Since you see bubbles into raw water I'm voting for a pinhole leak in the heat exchanger core. The cores are supposed to be sealed and not allow exchange to the raw water. I inherited an old boat one time that had a known leak in the heat exchanger. Symptoms were: would run fine for hours after an initial fillup with fresh water. but when the engine stopped the coolant would escape through the leak and would overheat if not refilled upon next startup. As long as the engine ran any loss of water in the heat exchanger was replaced with saltwater (essentially making the engine salt water cooled). But the heat build up and resulting pressure from a shutdown engine's heat sink would empty the water out of the heat exchanger down to the level of the pinhole leak.
The end cap for the heat exchanger or a leaking gasket for the end cap can also cause overheating but you would see salt or water all over the engine. Once my genset overheated from a pinhole leak when the cast iron end cap rusted out from the inside. Outside on the painted surface almost nothing was visible except a tiny rust mark with a thin tail-tale rust stain going down from it. Thankfully my genset is painted a light tan and it showed up. Now I do a freshwater flush of the unit when it sits at the dock for anytime without use. When cruising and using it regularly I don't bother but if I'm letting it set for a couple of weeks or more I flush it with Salt-X and leave it with fresh water inside. Just buying the parts and doing the labor myself it costs about $2K for the repairs each time.Two end caps, gasket set, mixer elbow, special long bolts, etc - and not including a cupernickel (sp) core which has always been fine. Before I started doing the freshwater rinse/flush i would get about 4 years out of a set of heat exchanger parts - now it is over 5 years and all seems well.

[fallingeggs]

Originally Posted by River Cruiser

I also have a 8.0 Westerbeke and had the same problem and did all the things mentioned to no avail. I finally found the gasket between the end plate and the exhaust manifold was allowing coolant to be pushed out the exhaust by the residual pressure in the system. Some models of the 8.0 have a one piece manifold in this type this can't happen


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This is what I was going to mention as well. My W33 had (and still has ) this problem. The aluminum exhaust manifold has corroded to the point where making a seal around the gasket and end plate is an issue. I'll replace the entire engine before spending $1,200 on an exhaust manifold...

[motion30]

Ok. radiator shop said the color did not leak. I picked it up today and pressure tested it myself and found that it had a large leak. I think it was in one of the tubes not the end plates. Is this repairable?

[fallingeggs]

Originally Posted by motion30

Ok. radiator shop said the color did not leak. I picked it up today and pressure tested it myself and found that it had a large leak. I think it was in one of the tubes not the end plates. Is this repairable?

In theory the tubes can be replaced by a good radiator shop, but I'm not sure the one you are using qualifies if you are finding leaks that they can't!

[Seeking Solace]

Originally Posted by motion30

Ok. radiator shop said the color did not leak. I picked it up today and pressure tested it myself and found that it had a large leak. I think it was in one of the tubes not the end plates. Is this repairable?

Glad you found the leak. Surprised you even found a radiator shop. They're getting few and far between since cars are going to plastic tanks. They've all shut down here that I knew about.

Your shop doesn't seem to have a good tech. Yes, they are repairable, but unless it was a defect in a weld point your going to find it's going to soon develop another leak. That is not saying gaskets aren't really replaced. If there are others that hold up better because of better materials or craftsmanship that's the direction I would take. The more expensive initial cost would likely be offset by future savings and less headaches. Unfortunately heat exchangers are going to deteriorate no matter what you do.

++ To the OP who flushes his system. Far better than letting salt water sit in it.

[meridian28]

I had mine tested and, yes it leaks. The shop wants to block off the bad tubes but that sounds like a band aid.. If one or more tubes are leaking, they are probably all ready to fail. I got a price from Lenco, $325.

[meridian28]

I replaced my heat exchanger and the problem is solved. I replaced the hoses at the same time as they had deteriorated.