Water in Westerbeke Gen Oil

scooper321

Well-Known Member
Jul 4, 2015
1,849
Baltimore, MD
Boat Info
2003 Sea Ray 400DB
Engines
Twin Cummins 6CTA-8.3
So I changed my oil this past weekend. Both engines and my gen. Engines were fine, nice and black. My Westerbeke 8.0BTDA generator, not so much. It’s always been black and pure, but now it’s more like coffee with milk in it. Consistency is fine - no jelly or anything But the color seems to signify water in the oil. The gen seems to run fine. But obviously this is concerning.

We did have an over temp shutdown event this summer. Lost a couple fins on the impeller and they clogged the flow. Didnt notice at the dock - it seemed fine when we left. But shortly thereafter the gen over temp alarm went off. Took a minute to figure out what the alarm was. By the time i did, i immediately shut off. It had already shut down, however. Temp reading on the gen meter was over 200. i don’t recall the exact number, but may have been around 220? We let it cool down and didn’t run it again until I inspected the impeller and fished out the lost fins. New impeller seems to throw water ok. And no other issues with gen the rest of the season. Noticed the raw water pump (original, old style) was leaking so I bought a new one, but haven’t installed it yet.

So whatever the cause, I know it’s not good. Diagnosing this is beyond my knowledge, patience, or equipment. But what am I realistically looking at? Blown head gasket? Cracked head? Cracked block? Like I said, it continues to run well. No leaking (other than at the pump) of anything. It’s just the oil coloring. Naturally, I’m not leaving it this way. I want to get it addressed before the winter, because I dont want water in the engine over the winter. Just looking for a little experience from the forum on what I might be looking at (and what I should ask the mechanic).

Thanks
 
@scooper321 Steve, I believe the shutdown temp is at 210 degrees and with 50/50 antifreeze and a 13lbs(?) cap the boil over is ~220 degrees.

How over filled was the oil level when you changed it and how many hours since the over heat?

My suggestion would be get a compression test done and if that is fine, a leak down should be performed. It is highly likely that the head gasket has been compromised from the over heat. That's the direction I would proceed with, a cracked block and I expect a lot of coolant loss consistently and the oil level to be very high.
 
@scooper321 Steve, I believe the shutdown temp is at 210 degrees and with 50/50 antifreeze and a 13lbs(?) cap the boil over is ~220 degrees.

How over filled was the oil level when you changed it and how many hours since the over heat?

My suggestion would be get a compression test done and if that is fine, a leak down should be performed. It is highly likely that the head gasket has been compromised from the over heat. That's the direction I would proceed with, a cracked block and I expect a lot of coolant loss consistently and the oil level to be very high.

Thanks. I wish I could remember the exact temps, but that sounds about the range it alarmed at. I recall looking it up after the event and determining that the thermal shutdown probably did operate properly - so I was hoping that meant the unit didn't implode. We shall see!

The oil level wasn't over filled. I checked the level before changing and it was in the correct range. That's when I first spotted the light coloring on the dipstick. But it wasn't over-filled. So perhaps I'm not getting a lot of water in there (he said, hopefully) but just enough to discolor it? The gen probably has maybe 20 hours on it since the event.

I didn't follow your last sentence about the cracked block... ?
 
Since you are at the beginning of the diagnostic. I would get the oil tested.....if you haven't already gotten rid of it. Blackstone will positively ID whether that is antifreeze or water.



If you have already gotten rid of the oil then the question becomes has the antifreeze level changed in the reservoir. If it hasn't that may point to a different issue of water intrusion.

For your mechanic:

1) Pressure test the cooling system. If that holds pressure you move on to the next step. If it doesn't hold pressure that indicates a possible head gasket, head, block, heat exchanger issue. A compression test as @Skybolt mentioned will held identify a head gasket issue but doing a compression test on a diesel engine requires special equipment.

2) If it holds pressure and you have not added antifreeze.....then the most likely source of the water is from ingestion. Your overheat event could have set in motion an issue where the exhaust water found its way back into the engine.

How? A generator is a balanced system. It requires a certain amount of water flow to keep it cool and push the exhaust out of the boat. For reference....your generator with a new impeller will generate about 2 psi of pressure in the system. So without that pressure you can create a condition where the water is drawn back up the exhaust as the generator cools off from an overheat.

I doubt you have a cooling system problem but it is easy to check.
My money is that you had an ingestion event tied to the overheat so you need to cycle the generator several times and change the oil a few more times. The over temp safeties did their job and protected the generator as they were designed to do.
 
@PlayDate Great advice and explanation(s). But if there isn't a systemic issue the oil would have cleaned itself up after 20hrs of running. At least from my experience. There isn't an oil cooler on the BTD/A's so raw water is highly unlikely.

Although if there isn't any antifreeze missing, then what John explains is possible. I have never heard of this happening with this type of exhaust. The BTD/A's have a vacuum break on the exhaust elbow, so I would think that couldn't happen.

While it's true the safety kill circuit should protect the engine to a degree, it is still possible with an older head gasket that it has been compromised. The cooling system leak down is a good suggestion, one I over looked.

But if it were me I would have a the compression test done. Yes because it is a diesel engine it requires special equipment for that engine. But the injectors don't need to be removed and it can be done through the glow plug orifices. You just need to get an adapter and also take the wire off of the fuel solenoid or fuel lift pump. But this is quite doable yourself if you are comfortable in doing this type of diagnostic.

If you have done compression test(s) before then this is pretty easily accomplished. Pull the glow plug(s) out and make an adapter from brass plumbing supplies to fit the compression tester hose and away you go. No more then an hour. The leak down test (if needed) would be a little tougher, but still can be accomplished in the same manner.
 
... I didn't follow your last sentence about the cracked block... ?

If there was a cracked block I would expect a lot of coolant loss into the engine and that would cause the oil level to raise. Most of the water will boil off while the engine is running, but there will still be a small amount of fluid that won't and will be left in the oil. Ethylene Glycol being one of them, that usually will not boil out completely. Enough of it and it will discolor the oil. But since you didn't notice any real level drop in anti freeze and no increase in the oil level, @PlayDate's advice on the pressure testing of the cooling system is sound advice. That will also tell you if there is an issue or not.

If you decide to do that yourself, there are kit's from amazon that are readily available. In doing that test do not go more then 5lbs above the reservoir's cap rated pressure. That is usually stamped into the cap.
 
My 8.0 BDT blew the head gasket in May. $4500 later I was up and running within 2 weeks.
 
My 8.0 BDT blew the head gasket in May. $4500 later I was up and running within 2 weeks.

I'm prepared for the financial hit. That number is harsh but it's a lot easier to stomach than a new gen!

@PlayDate and @Skybolt: Thanks for the insight on what to look for and how the gen operates. I should say that I have NOT checked the coolant level - only the oil level. I'll have to stop at the boat and look into that one. Even though I didn't check the coolant level, I think I would have noticed the evidence of coolant leakage... I don't recall my stern bilge being pink at all, or any pink around the gen itself. Maybe I'm trying to convince myself of something but I'm going to hold on to this as meaning my head and block might just be OK. At this point, I'm OK with needing a new head gasket...

And yes, I take oil samples every year, so I do have samples of the gen oil. That's when I first noticed the discolorization. They go out to Blackstone this week. Maybe I'll give them a jingle to see if they can prioritize testing the gen sample for me...

My estimate of 20 hours may be high. The overheat event occurred at the start of our Baltimore to Chesapeake City to Cape May to OC to Ches City to Baltimore trip last summer. I shut the gen off when the event happened and didn't run it again until I had changed the impeller and fished out the fins. What I don't remember is how long (or if) I ran the gen after doing that repair. I did notice there was water dripping and decided to get a new raw water pump, so I know I ran it some (figuring that dripping wouldn't sink the boat). And 20 hours would be a high estimate if I ran it the whole rest of the trip (which I doubt). I didn't run the gen much after that this season. Thank goodness for strong batteries, good alternators and a AC and DC fridge!

I do like the sound of the water ingestion idea... that's certainly the lowest cost/lowest trouble possibility. It gives me hope that I can change the oil, run it, and eventually burn out anything in there. Thanks for raining on that parade, Sky! LOL. But I do have about 3 gallons of Rotella left over, so maybe I'll run it up to temp and change the oil once or twice, just to see if that helps clear it up.

Did I mention that I need a new raw water pump on my port engine, too? In my boat, that's the tough one to get to, too! So much for any electronics upgrades this year!
 
I'm prepared for the financial hit. That number is harsh but it's a lot easier to stomach than a new gen!

@PlayDate and @Skybolt: Thanks for the insight on what to look for and how the gen operates. I should say that I have NOT checked the coolant level - only the oil level. I'll have to stop at the boat and look into that one. Even though I didn't check the coolant level, I think I would have noticed the evidence of coolant leakage... I don't recall my stern bilge being pink at all, or any pink around the gen itself. Maybe I'm trying to convince myself of something but I'm going to hold on to this as meaning my head and block might just be OK. At this point, I'm OK with needing a new head gasket...

And yes, I take oil samples every year, so I do have samples of the gen oil. That's when I first noticed the discolorization. They go out to Blackstone this week. Maybe I'll give them a jingle to see if they can prioritize testing the gen sample for me...

My estimate of 20 hours may be high. The overheat event occurred at the start of our Baltimore to Chesapeake City to Cape May to OC to Ches City to Baltimore trip last summer. I shut the gen off when the event happened and didn't run it again until I had changed the impeller and fished out the fins. What I don't remember is how long (or if) I ran the gen after doing that repair. I did notice there was water dripping and decided to get a new raw water pump, so I know I ran it some (figuring that dripping wouldn't sink the boat). And 20 hours would be a high estimate if I ran it the whole rest of the trip (which I doubt). I didn't run the gen much after that this season. Thank goodness for strong batteries, good alternators and a AC and DC fridge!

I do like the sound of the water ingestion idea... that's certainly the lowest cost/lowest trouble possibility. It gives me hope that I can change the oil, run it, and eventually burn out anything in there. Thanks for raining on that parade, Sky! LOL. But I do have about 3 gallons of Rotella left over, so maybe I'll run it up to temp and change the oil once or twice, just to see if that helps clear it up.

Did I mention that I need a new raw water pump on my port engine, too? In my boat, that's the tough one to get to, too! So much for any electronics upgrades this year!

I am hoping it is something simple.

So what you are looking for is coolant finding its way into the oil. The easy evidence that supports that is the coolant reservoir and looking under the pressure cap. If the coolant level is low in the reservoir or under the pressure cap.....that is a problem. There will not be any coolant laying around the bilge surrounding the generator. If coolant found its way into the engine......it would have displaced oil and raised the oil level in the engine. Coolant is heavier than engine oil and would settle to the bottom of the oil pan.

That's why doing a simple pressure test is the easiest way to determine if you had a gasket failure. I have one if you want to borrow it.

It is on my boat in DC.

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The overheat event occurred at the start of our Baltimore to Chesapeake City to Cape May to OC to Ches City to Baltimore trip last summer. I shut the gen off when the event happened and didn't run it again until I had changed the impeller and fished out the fins. What I don't remember is how long (or if) I ran the gen after doing that repair.

With this I am going to amend my previous comments about water intrusion. If you operated the boat with the sea cock open and the impeller was seriously compromised.....water under hull pressure will push by the impeller and potentially create an intrusion event by filling the exhaust side with water (similar to cranking the generator for extended periods and it not starting). This is much more common than having it show up from the exhaust side as I described earlier.
 
For some positive news, I had my 10BTD shut down due to an overheat. The heat ex failed and drained all the coolant. I replaced the HE, refilled and all has been great for 4 years and 700 hrs. So there is hope that it is not catastrophic. Good luck!
 
Sorry @scooper321 Steve, didn't mean to bust any bubbles, but here's another one. If the sea water found it's way past the raw water pump and made it's way into the engine, I would expect that a hydro static lock would have happened, as that is common for that kind of breakdown.

I would proceed as John suggest's and do a pressure test of the cooling system. If that fails, pulling the head may be just cause for investigation.

I also have that pressure test kit if you would like to borrow it, if I am closer? It's in Kent Narrows.
 
Sorry @scooper321 Steve, didn't mean to bust any bubbles, but here's another one. If the sea water found it's way past the raw water pump and made it's way into the engine, I would expect that a hydro static lock would have happened, as that is common for that kind of breakdown.

I would proceed as John suggest's and do a pressure test of the cooling system. If that fails, pulling the head may be just cause for investigation.

I also have that pressure test kit if you would like to borrow it, if I am closer? It's in Kent Narrows.

Now that’s what I was thinking. Water in the engine would lock it up. That hasn’t happened. So I’m staying optimistic. One thing I don’t know is when the AC and HE on the gen were last serviced. The prev owner was pretty anal about servicing the boat, but stuff happens.

I’m intrigued about running the coolant system pressure test. That would allow me to make some progress diagnosing. The Ravens play Thursday night so the weekend is wide open. Just watched a video. Looks pretty easy to test. Is there anything unique about testing a diesel gen vs a gas car?
 
Best results come from both a cold and hot (operating temperature), cooling system pressure test, if at all possible.

How do you do a hot test? Connect the tester and then run the engine to temp?

@Skybolt If I bought that Stant kit, would I need any adapters?
 
Now that’s what I was thinking. Water in the engine would lock it up. That hasn’t happened. So I’m staying optimistic. One thing I don’t know is when the AC and HE on the gen were last serviced. The prev owner was pretty anal about servicing the boat, but stuff happens.

I’m intrigued about running the coolant system pressure test. That would allow me to make some progress diagnosing. The Ravens play Thursday night so the weekend is wide open. Just watched a video. Looks pretty easy to test. Is there anything unique about testing a diesel gen vs a gas car?

Nope just takes about 15-20 minutes. Most of it is just looking for a drop in pressure. If there is a leak, you won't be able to get it to the desired pressure. But if you can, then let it sit for ~15 minutes and monitor the gauge. Just don't go more then 5lbs above the cap's listed pressure. possibly use a little silicone grease on the test cap to help seal it better.

Your welcome to borrow mine or try one like this: https://www.amazon.com/HZAUTOS-Pres...s&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGZfbmV4dA&psc=1

You only will need one of the steel cap's. But should do the trick.
 
@scooper321 Steve, the hot test is a bit tougher. You need to let the generator come up to temp and then turn off and open the cap. Then put the tester on and do the test. You could put the adapter on first then start the engine. But I prefer to do it the hard way. Use a towel to open the cap when hot.

I would do the cold one first and see what happens. Possibly do the hot test afterwards. Personally the cold test should revile the leak quicker then the hot test. The hot test is useful because your testing the system at it's operating temperature. Any metal leaks (crack(s)) would be reviled by that quicker.

Personally if there is a leak I believe it will be a head gasket. In doing the test, first make sure the tank with the cap on it is full. You should also look for external leaks while it is pressured and that is more easily done when cold.
 
@scooper321 Steve, the hot test is a bit tougher. You need to let the generator come up to temp and then turn off and open the cap. Then put the tester on and do the test. You could put the adapter on first then start the engine. But I prefer to do it the hard way. Use a towel to open the cap when hot.

I would do the cold one first and see what happens. Possibly do the hot test afterwards. Personally the cold test should revile the leak quicker then the hot test. The hot test is useful because your testing the system at it's operating temperature. Any metal leaks (crack(s)) would be reviled by that quicker.

Personally if there is a leak I believe it will be a head gasket. In doing the test, first make sure the tank with the cap on it is full. You should also look for external leaks while it is pressured and that is more easily done when cold.
Thank you Sir, for typing that for me. JK but spot on.
Oh, yep, the hard way is better.
 
@scooper321 Steve, the hot test is a bit tougher. You need to let the generator come up to temp and then turn off and open the cap. Then put the tester on and do the test. You could put the adapter on first then start the engine. But I prefer to do it the hard way. Use a towel to open the cap when hot.

I would do the cold one first and see what happens. Possibly do the hot test afterwards. Personally the cold test should revile the leak quicker then the hot test. The hot test is useful because your testing the system at it's operating temperature. Any metal leaks (crack(s)) would be reviled by that quicker.

Personally if there is a leak I believe it will be a head gasket. In doing the test, first make sure the tank with the cap on it is full. You should also look for external leaks while it is pressured and that is more easily done when cold.

Thanks. These testers aren’t too expensive. May be good to have one on hand. Looks like the key is getting one with metallic adapters, not plastic. I’m going to get one for myself and do the test. Appreciate the offer of the loaner though. Between gas, tolls and time, it’s cheaper to get my own! Lol.
 
Thanks. These testers aren’t too expensive. May be good to have one on hand. Looks like the key is getting one with metallic adapters, not plastic. I’m going to get one for myself and do the test. Appreciate the offer of the loaner though. Between gas, tolls and time, it’s cheaper to get my own! Lol.

I actually use it when I change the antifreeze out in my engines. I also test the pressure and look for leaky hoses etc. I find it very useful in early detection of failing hoses and clamps. I go 5 lbs. above the cap pressure which should revile any possible failures before they happen.
 

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