Westerbeke 8 kw cooling issue

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Steve91T

Guru
Joined
Sep 12, 2016
Messages
898
Location
USA
Vessel Name
Abeona
Vessel Make
Marine Trader 47’ Sundeck
This is for our new to us Marine Trader. During sea trips it shut down after 20 minutes. Boat yard looked at it and said the cooling side was a mess. Needs impeller and heat exchanger clogged. They put it together as is.

Now that it’s ours, I started it and ran it for over an hour with a load. Seemed to be cooling just fine, but the exhaust was loud and I feel like it should have more water flow. But then again I have nothing to compare to. It is also hard to get started. 5k hrs on it.

I think I can pull the heat exhanger off and have it cleaned?

Anything to do about the hard starting?

https://youtu.be/k9G_lUo4Vzw
 
Check the header tank full. If not it will run hot.
Check the little hole to the overflow line is not plugged.

Get an infrared temperature gun and take temp readings:
Exhaust riser temp
Header tank temp
Hx inlet temp/coolant side
Hx outlet temp / coolant side
Sea water pump casing temp
Oil filter temp

Using the temp gun get as close as possible to get most accurate readings. Remember that the laser is only the aiming device. You must be close to prevent detection of the surroundings which dilutes the peak readings.

Hard starting can be malfunctioning glow plugs, low compression or slow starter speed from various causes.

The hx end caps are easy to remove to check for junk.

I have some baseline temp readings for my old 8 BTD somewhere.

The water flow looks low to ok but the white vapor says it is hot. Could be ambient temp or high humidity.
 
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Check the header tank full. If not it will run hot.
Get an infrared temperature gun and take temp readings:
Exhaust riser temp
Header tank temp
Hx inlet temp/coolant side
Hx outlet temp / coolant side
Sea water pump casing temp
Oil filter temp

Using the temp gun get as close as possible to get most accurate readings. Remember that the laser is only the aiming device. You must be close to prevent detection of the surroundings which dilutes the peak readings.

Hard starting can be malfunctioning glow plugs, low compression or slow starter speed from various causes.

The hx end caps are easy to remove to check for junk.

I have some baseline temp readings for my old 8 BTD somewhere.
The water flow looks ok but the white vapor says it is hot. Could be ambient temp or high humidity.

The water temp gauge was between 175 and 200 depending on when I looked at it.

This was in Florida. 90 something degrees and humid.
 
Mine runs at about 180 . WMD 7.7 westerbeke.
 
200 on the gauge is right on the max edge. It should be 175-195F per the operator manual.
 
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That generator has a overheat safety switch that could be shutting it down. The raw water impeller is not difficult to change except that it is mounted on the back side. I found that removing the complete pump from the engine is the easiest way to do it. You will have to work over the top of the engine to get to it.

You could take the heat exchanger off and have a radiator shop clean it out, or you could buy the chemicals such as Rydlyme or Barnacle Buster and do it yourself. There are videos on those companies web sites that explain how it is done. I have done it to my Ford Leymans and Westerbeek generator.

Not sure about the starting issue. Are you energizing the glow plugs for at least 10 seconds? If you can start the generator from the engine room, make sure the fuel solenoid linkage is pulling all the way in when the glow plugs are turned on. Also, don't keep cranking on the engine if it is not starting as you could fill the exhaust system with water that could back up into the engine and destroy it.
 
Take the HX off and clean it. Put a new impeller in. 200F is too hot, it should run about 180F. And there should be plenty of water coming out the tailpipe.

Impeller and HX cleaning are not difficult and are considered normal maintenance.

I would not rely on a mere chemical flush to resolve this. Works for minor fouling, but once things get plugged up it is not the fix.

Make sure that sea water pump is not leaking out of the seal leak off ports. If so, replace pump with the upgraded one with mechanical vs. lip type seals,
 
How much should I expect to pay to have the heat exchanger cleaned?
 
Probably $500-1000, depending on how close the mechanic is and what is needed.

If you are pretty handy, well within the scope of DIY.
 
Probably $500-1000, depending on how close the mechanic is and what is needed.

If you are pretty handy, well within the scope of DIY.

Sorry that’s what I meant, how much to have it cleaned if I brought the heat exchanger to a shop.
 
Probably less than $100.00. They will just soak it in a chemical bath. If you want it pressure tested because you suspect it is leaking internally, that would be extra.
 
Yea, under $100 to have it cleaned once off the boat. Get new end cap gaskets first, they are SenDure and sized according to HX diameter. Probably 3". No need to go to Westy for them.
 
Gotcha thanks guys!
 
Hey we’re headed to the boat next week. So is the genny a closed cooling system? Antifreeze? Is the heat exchanger easy to remove? What are end caps and what gaskets do I need? Also what impeller do I need?

Thanks guys!
 
Hey we’re headed to the boat next week. So is the genny a closed cooling system? Antifreeze? Is the heat exchanger easy to remove? What are end caps and what gaskets do I need? Also what impeller do I need?

Thanks guys!


With all due respect, with that list of questions you need a good mechanic to do the work. But if he doesn't mind, watch and ask those questions and then DIY next time.



David
 
With all due respect, with that list of questions you need a good mechanic to do the work. But if he doesn't mind, watch and ask those questions and then DIY next time.



David

Hell no! I do all my own work. Pulled motors out of engines, rebuilt turbos, built couple of decks, next I’m going to paint my car. Everything I learn is off the internet.

Granted I probably should have started googling first, but since there are so many experienced people here, I thought I’d just ask.

My disadvantage is I’m 650 miles away and I want to be able to get it all done in one shot when we go there in a few days. If I have to order a part, I’d like to do it now so it’ll be there when I need it.
 
The parts manual is available in the WB site that shows the hx, and pump.
The heat exchanger is a water to water cooler, like a radiator cooled by water instead of air.
Seawater is pumped through the “tube side “ of the hx. The “end caps” allow access to the inlet and outlet of the tubes for cleaning and inspection. These caps have a heavy rubber gasket, that if carefully removed, can be reused several times. Just one bronze bolt holds each cap on.
I would inspect both ends and replace the pump impeller before pulling the hx.
 
The parts manual is available in the WB site that shows the hx, and pump.
The heat exchanger is a water to water cooler, like a radiator cooled by water instead of air.
Seawater is pumped through the “tube side “ of the hx. The “end caps” allow access to the inlet and outlet of the tubes for cleaning and inspection. These caps have a heavy rubber gasket, that if carefully removed, can be reused several times. Just one bronze bolt holds each cap on.
I would inspect both ends and replace the pump impeller before pulling the hx.

Thank you. So the boat yard that inspected it during pre purchase inspection said the hx was clogged and the impeller needed to be replaced. So I think it needs to be removed and cleaned.
 
Thank you. So the boat yard that inspected it during pre purchase inspection said the hx was clogged and the impeller needed to be replaced. So I think it needs to be removed and cleaned.


Right, just do it. Cleaned, new gaskets, new impeller, and carefully inspected raw water pump. Maybe also check the exhaust elbow while you are at it. Once done, you will have a reliable generator.
 
In that case the hx just unbolts. It’s full of antifreeze and seawater.
 
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There is a drain cock on the bottom of the heat exchanger that will drain the salt water. Also, there is a anode screwed into it. Replace that now and remember to add this to your regular maintenance on the generator. I would check this anode every couple months until you establish how long it can go between changes. It sounds like you are going to take it to a shop to be cleaned? If so it will probably come back with no paint on it. So you will need some red paint. Is there a chance the hoses will be damaged in the removal process? Might need new hoses. You will need new antifreeze.

You might consider ordering all these parts from a Westerbeke dealer (have you checked to see how far away the nearest dealer is?)and write down all the parts numbers so you can source some aftermarket parts next time. Or look at the parts catalog to get the OEM numbers and then search for the parts in the aftermarket.

The impeller will come with the necessary gaskets and lube you will need. You may need a puller to get the old one out. It's a fairly small impeller so maybe not.
 
Impeller is a Johnson 09-810B-1. buy several. It is never too early to start a parts stock.
 
Impeller is a Johnson 09-810B-1. buy several. It is never too early to start a parts stock.

On my WB 12.5, there are two different impeller drive pin sizes dependent upon which pump you have. The newer pumps use smaller pins. Be sure the new impeller pin matches the old, impellers are the same.
 
Greetings,
Mr. TOG. I've read that it may not be a good idea to store impellers for too long due to the potential degradation of the "rubber". Perhaps staying one ahead of replacement is prudent.
 
On my WB 12.5, there are two different impeller drive pin sizes dependent upon which pump you have. The newer pumps use smaller pins. Be sure the new impeller pin matches the old, impellers are the same.

Same for the 8kWs...2 pumps, same impellers but different pins...good news is you can push the pins out and swap them, I made a spare by grinding off a hair on the spare pin.
 
Greetings,
Mr. TOG. I've read that it may not be a good idea to store impellers for too long due to the potential degradation of the "rubber". Perhaps staying one ahead of replacement is prudent.

I know heat degrades rubber but if it were kept cool (like we used to do with camera film) perhaps they would store longer? Just let it warm up before you use it?
 
There is a drain cock on the bottom of the heat exchanger that will drain the salt water. Also, there is a anode screwed into it. Replace that now and remember to add this to your regular maintenance on the generator. I would check this anode every couple months until you establish how long it can go between changes. It sounds like you are going to take it to a shop to be cleaned? If so it will probably come back with no paint on it. So you will need some red paint. Is there a chance the hoses will be damaged in the removal process? Might need new hoses. You will need new antifreeze.

You might consider ordering all these parts from a Westerbeke dealer (have you checked to see how far away the nearest dealer is?)and write down all the parts numbers so you can source some aftermarket parts next time. Or look at the parts catalog to get the OEM numbers and then search for the parts in the aftermarket.

The impeller will come with the necessary gaskets and lube you will need. You may need a puller to get the old one out. It's a fairly small impeller so maybe not.

Thank you sir. That’s exactly what I was looking for. Your few minutes of time will save me hours.
There’s a westerbeke dealer near the marina, so I think I’ll just bring the parts in and that way we can match them up. I’ll get two of everything so I can have spares.
 
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