Westerbeke 8 kw cooling issue

[Steve91T]

So the video I posted in my original post, doesn’t the generator sound a bit loud? The genny exhaust is louder than the mains! Also is it spitting water like that because the exchanger is clogged? Seems like it should be a more steady flow of water.

 

[Ski in NC]

No where near enough water flow. Impeller or clogged hx, address both. It will be quieter when water flow is normal as the muffler works better then.

 

[koliver]

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.

If the boat yard already inspected and found the impeller missing vanes, how did it get put back together without a new impeller? Likewise if they inspected the HX and found it clogged, how did it get put back together without being un-clogged? Sounds more like they theorized that is what would be found on inspection, but didn't do any.

When you do your impeller, if you find any vanes are missing, you know to pull the end off of the HX to recover the broken rubber bits. Broken bits of zinc may also be in that location. That may clear up your "HX plugged up" problem, if such exists.

 

[Steve91T]

If the boat yard already inspected and found the impeller missing vanes, how did it get put back together without a new impeller? Likewise if they inspected the HX and found it clogged, how did it get put back together without being un-clogged? Sounds more like they theorized that is what would be found on inspection, but didn't do any.

When you do your impeller, if you find any vanes are missing, you know to pull the end off of the HX to recover the broken rubber bits. Broken bits of zinc may also be in that location. That may clear up your "HX plugged up" problem, if such exists.

Part of my offer was to have the generator cooling issue resolved. Once at the boat yard, they found everything wrong that I mentioned and the owner was tired of messing with the boat. He said to put it back together as is and he offered me $6k off the price of the boat to take it as is.

 

[RT Firefly]

Greetings,
Mr. 91. $6K? Fair enough. I am in agreement with all posted thus far and cleaning the HE and replacing the impeller should be a LOT less that $6K. As to the missing impeller vanes. You might find pieces in the HE, as Mr. k suggests BUT they could also be lodged in the oil cooler which should be the first item downstream of the water pump. Pull off a hose and take a good look.

 

[Steve91T]

Greetings,
Mr. 91. $6K? Fair enough. I am in agreement with all posted thus far and cleaning the HE and replacing the impeller should be a LOT less that $6K. As to the missing impeller vanes. You might find pieces in the HE, as Mr. k suggests BUT they could also be lodged in the oil cooler which should be the first item downstream of the water pump. Pull off a hose and take a good look.

Yeah the argument was I’m taking a chance that this generator might need to be replaced, which is a bucket of money. But I’m going to do my best to keep this one alive. Plus the windless doesn’t work. I just didn’t want people thinking the boat yard was to blame, they were just doing what they were told.

I’ll make sure to look in the oil cooler as well if I’m missing veines.

 

[Ski in NC]

No oil cooler on that machine. Vane chunks will be in coolant HX.

 

[RT Firefly]

Greetings,
Thanks Mr. Ski. HE/HX it is...

 

[motion30]

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.

I ran into the same thing tried to put the impeller on but it would not go through the slot. I was able to take the smaller pin out of the old impeller and install it in the new impeller

 

[SailorGreg]

Steve, plenty of good advice already. One comment, the torque setting for the bolts in the end caps is low. Easy to crack the cap if you get too energetic. I forget the number so look it up. If you are going to do your own maintenance get the shop manual. For some of these machines there is also an O ring on the end of the bolt. Pay attention to the sequence of bolt, cap, O ring, gasket.
You will also need guidance when re- filling the coolant so that you clear all the air out. Takes practice.

 

[SailorGreg]

And Steve, my 8kw had an oil cooler, so check. It might have been an option at the time of purchase.

 

[83GB]

I have an 8 KW BTD Westerbeke with about 5000 hours. My raw water pump started dripping at the seals so I lazily sent it to DEPCO (pump experts) for repair. They told me the pump I had was an early version and it did not have a wear plate behind the impeller. Years of the spinning impeller caused the back inside side of the pump to wear allowing raw water to "slide" around the impeller... I bought a new pump and the quantity of raw water exiting the side of the boat increased significantly...

 

[RT Firefly]

Greetings,
Mr./Ms. 83. Welcome aboard.

 

[Trawlerman]

One thing is sure, the amount of water coming out the exhaust is ridiculously low. There should be much more. Either the seawater pump is not working properly, or there is a restriction. You have been given lots of ideas of what could cause this issue, so you need to check them one by one. Pump, then HX, then mixing elbow, etc. Nobody is going to beeline straight to the issue, so do your work.

 

[Steve91T]

One thing is sure, the amount of water coming out the exhaust is ridiculously low. There should be much more. Either the seawater pump is not working properly, or there is a restriction. You have been given lots of ideas of what could cause this issue, so you need to check them one by one. Pump, then HX, then mixing elbow, etc. Nobody is going to beeline straight to the issue, so do your work.

What are you taking about, I am doing my work.

 

[twistedtree]

I’m real interested to hear what repairs you ultimately do, and what improvement you see. It sure sounds like basic deferred maintenance, and nothing more.

 

[FoxtrotCharlie]

I feel your pain. Our new boat had a suspect 12k WBK Gen. Cost to repair elec end was too much for a 30 yr old gen with 5000 hrs. So out with the old, and in with a new one - got a few more $$ off as you, so I'll be out a few boat bucks - but will have a shiny 9k gennie (don't need 12k as the original elec stove was replaced with propane). I do like the Machiavellian approach - clear out all of the old at the start!

 

[Steve91T]

Thanks guys. I have a mechanic going to the boat today to give me an estimate. He does a lot of work at this marina and same highly recommended. From his ballpark estimate he’s really not glnhg to charge me more than a few hours of labor. Since we really want to get the boat to the keys soon, I think I’ll let him clean the heat exchanger and replace the impeller.

A few days ago we were on the boat and I started the generator. This time I held the preheat down for about 15 seconds and she started right up. I was really happy about that.

I didn’t run it long. Just wanted to see if me not holding the preheat long enough was why it was hard to start, and it was.

I’ll keep you guys posted! Thanks again for all the help. I’m feeling confident that cleaning the heat exchanger and replacing the impeller wil do the trick!

 

[Maerin]

It's possible that one or more glow plugs has failed. They're not difficult to DX, and not terribly complicated to replace.



If the pump cover plate is worn, replacing it with a new one can dramatically improve the amount of water the pump will move. In a pinch, the old one can sometimes be flipped or re-faced. Make sure the shaft seal isn't leaking.


My 12.5 KW gave me all sorts of grief with the seawater pump, I was replacing impellers every other oil change, seals every 400 hrs, it was mean to access and a mess with seawater leaking onto the block. I ultimately pulled the seawater pump, fabricated a blank-off plate and installed a 120V centrifugal pump that's powered by the generator. I never looked back! No more impellers, the electric pump was less costly than a new pump, FAR less maintenance, and delivers a consistent volume of water, very quiet. That was almost 10 yrs ago, same pump has been serviced once with new shaft seal, and about 2,000 hrs. Just an option if the seawater pump is a problem child.

 

[sunchaser]

Do you have the specs for the electric drive pump? Interesting alternative for access challenged front ends.

BTW, changing impellers every 300 hours or so doesn't sound like a bad idea, or every 12-18 months or so for lighter use boaters. The newer design WB pumps seem to have dealt with the seal issue.

 

[psneeld]

For a 8kw, the small March AC pump is about right.

Something like 500 to 800 gph.

Larry M had a great article from the KK Owners Magazine that described it.

Maybe he can post that link again...maybe I can find it but cruising the Chesdie and not sure which computer it's on.

 

[Maerin]

Do you have the specs for the electric drive pump? Interesting alternative for access challenged front ends.

BTW, changing impellers every 300 hours or so doesn't sound like a bad idea, or every 12-18 months or so for lighter use boaters. The newer design WB pumps seem to have dealt with the seal issue.

Data sheet and pump curves attached. Available from Depco. Cheaper than a new OEM seawater pump.



The service life of the seals was the impetus for the conversion. Although a newer series replacement may have ended the seal issues, would still require regular impeller changes. So, electric was the choice. WAAYYY better! One caveat though, I ended up adding a relay to power the pump that is paralleled to the "preheat" switch/relay. It keeps the pump de-energized until the genset gets up to speed, ergo voltage. Allowing the pump to see the ramp-up voltage eventually toasts the capacitor. The relay is a relatively simple delay to prevent that, and has been flawless for a couple thousand hours.

 

[Steve91T]

Hey guys thought I’d update. Because I’m nowhere near the boat, it would have been a PITA to get the heat exchanger cleaned. So I found a local mechanic that lives on a boat at the marina and he got the heat exchanger cleaned and also replaced the impeller which was missing some veines. He said it pumps a ton of water now! That was a few hours of labor well worth the moneys.

Thanks guys for the help!

 

[neworleansrich]

I am a big fan of using mag-drive 120v pumps on generators (as long as the generator is above the waterline). I've been running generators like this for 20 years with much better reliability.

The specific issues with the Westrebeke 8kw is a crappy raw water pump. Like I said, replace it with Little Giant or March pump. Make a backing plate or just take the impeller out of the Westerbeke pump and bypass it. Wire the AC pump directly to the generator output (with a fuse), so it comes on when the generator makes AC current.

Also:

The coolant overflow hole in the coolant cap housing is very small and tends to clog. The overflow tank will look fine, but the coolant level in the engine goes down. You need to make sure its open with a piece of wire.

If you are monitoring temp on a remote panel, a bad ground wire or a bad 12v connection will cause the temp reading to be off. Measure the voltage at the remote panel with the generator running. Try measuring the voltages with another wire running back to the generator. Isolate the bad connection and both the temp and oil pressure will improve on the gauges.