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Aargh... Milkshake Engine Oil... WTF? (Port Engine, 2016 AR240, ~300 hrs)

We noticed your absence over the past few weeks, glad to hear from you. What a frustrating scenario. It's beyond my scope of knowledge... It's a situation where I would hope my dealer/dealer's mechanics were competent. It sounds like you have that. I'm interested to hear the cause, hopefully it's relatively minor. Best of luck with that and your work opportunities.
 
Okay, trying to "risk stratify" potential failure modes here (thank you guys for excellent suggestions!):
  1. Cracked/frozen oil cooler.
  2. Head gasket issue.
  3. Cracked exhaust manifold.
  4. Cracked cylinder head.
  5. Engine block (crack?).
I think the next two are less likely based on my preliminary observations, albeit there is always a chance:
  1. Oil filter failure.
  2. Air filter box/water ingestion.
The most worrisome, to me, would be a scenario w/some sort of hidden, gradual excessive heat damage, for example cavitation related. Such as exhaust manifold damage, as mentioned by @Cambo. That would make me nervous about ballasting (listing) the boat and surfing which we have been doing (and enjoying) - a lot! In this regard, my new 6CW impellers do not seem to cavitate much at all but that is potentially misleading/inaccurate feeling. Come to think of it, plowing a heavily ballasted/listed hull through water at 10mph with pumps revving at 6,000+ RPM - there could easily be some air bubbling/ventilation happening...
Well, let's hope it is something simple... like the oil cooler. And no need for a new engine (ouch!).

A thought of starting a poll has crossed my mind (yes, I'm tired!) but I'm not going to do that, yet, lol.

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We noticed your absence over the past few weeks, glad to hear from you. What a frustrating scenario. It's beyond my scope of knowledge... It's a situation where I would hope my dealer/dealer's mechanics were competent. It sounds like you have that. I'm interested to hear the cause, hopefully it's relatively minor. Best of luck with that and your work opportunities.
Absolutely! I'm hoping the dealer can diagnose this, and it won't be catastrophic! But we'll see!
I'll be checking this thread sporadically, I knew you guys would give me some ideas to work with.

Yeah, this is not the best time for me right now to deal with a nonsense like that as we're planning a potential cross-country move, lol. But I would hate to lose the boat/engine and not gonna let it sit, glad I sneaked out and went riding this morning, actually.

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I had the covers on both my boat’s oil coolers crack, it only caused the oil to leak into the bilge and mix with the water there but I imagine an internal crack could lead to water mixing with the the oil quickly.

On my waverunner with an mr1 engine, I found water in the oil once and my neighbor an ex post office mechanic thought it was caused by a leaking head gasket. This eventually led to a bad rectifier and finally a bad ecu. This was determined through process of elimination by an experienced PWC tech.

If either of these things is what happened to your engine I’d hope it was the oil cooler, it’s not cheap but cheaper than a new ecu. Neither speaks to why your oil was cooked. Mine looked like chocolate milk both times. Good luck.
 
Absolutely!...

Yeah, this is not the best time for me right now to deal with a nonsense like that as we're planning a potential cross-country move, lol. But I would hate to lose the boat/engine and not gonna let it sit, glad I sneaked out and went riding this morning, actually.

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East or West? Since you are kind of in the middle of the country now. Hopefullly South has something to do with the move.
 
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I had the covers on both my boat’s oil coolers crack, it only caused the oil to leak into the bilge and mix with the water there but I imagine an internal crack could lead to water mixing with the the oil quickly.

On my waverunner with an mr1 engine, I found water in the oil once and my neighbor an ex post office mechanic thought it was caused by a leaking head gasket. This eventually led to a bad rectifier and finally a bad ecu. This was determined through process of elimination by an experienced PWC tech.

If either of these things is what happened to your engine I’d hope it was the oil cooler, it’s not cheap but cheaper than a new ecu. Neither speaks to why your oil was cooked. Mine looked like chocolate milk both times. Good luck.
Did not consider the rectifier, that’s a good point, while oil cooler seems in the lead of things to consider.

By “cooked” I mean frothy, or foamy, chocolate milkshake would be a good description, also coming up high on the dip stick. Don’t know if it separates, but I’m assuming it’s most likely water intrusion, there is no smell of gas.

 
East or West? Since you are kind of in the middle of the country now. Hopefullly South has something to do with the move.
Huh! Good question. Being recruited by two organizations w/ three possible locations on both coasts... so I’m not sure where I’ll end up but almost certainly moving out of my current position in St. Louis (after 20 years in here!).
Im excited about the project itself enough I don’t care which location or coast, lol. I’ll elaborate when things settle down, I feel pretty uprooted already, not a great feeling for me, but Kate and the kids seem to be taking it just fine.
And there is lots of things yet to consider.

 
@swatski Sorry to hear about troubles with the boat. It's always a little scary to hear these things. Hopefully it's an easy fix and not due to listing the boat for surfing. But it sounds like you have some good oppurtunities in the works. Best of luck with both.
 
You have been missed @swatski. Lots of good ideas on the possible cause already. The first thing you got was an oil pressure warning not an engine temperature warning? Any oil in the pisser lines?

Enjoy what sounds likely to be your last holiday season in St Louis. The boat will work out. You could always just ask for new boat money as your signing bonus.
 
You could always just ask for new boat money as your signing bonus.
I like the way this guy thinks.

As one of what I would consider to be the best maintained boats on the site, it hurts too see you having problems. Getting lots of good advice here, the only thing I have to add is to NOT run that engine again until you get the oil changed out. Poor lubrication is the quickest way to ruin bearings in any machine, even beyond overloading them.

Good luck, with both the boat and the new venture.
 
With the dealer doing a leak down test I'm fairly sure this will confirm that the cylinder head / head gasket are good. The oil cooler should be able to be disconnected and checked with a pressure test to make sure its not leaking. The exhaust manifold could potentially be checked with an infrared temperature gauge Im not sure if the aluminum will sink the heat away and equalize the reading but it should have a hot spot due to the gasses entering the water jacket

Photo compliments of @fairpilot with the potential hot spot areas marked up If the boat is run for a short time with no water you may be able to measure these areas and see if you get a spot that is much hotter identifying the potential issue. Since 90% of motors that the dealer works on are jet ski motors I don't think its as prevalent with one motor your more likely to notice the cavitation it gets masked with two motors so damage to the manifold is not that prevalent on PWC motors. The manifold pictured below is upside down in relation to its mounting position on the boat it also makes sense that the breach points that were reported are at the top air bubbles rising to the top not allowing proper cooling and the water jacket gets roasted from the exhaust gasses. That is the hottest part of any motor on other types of motors its not uncommon to actually see that area glow red

108275


vpJlSYm.jpg
 
If you need any help i can volunteer @Betik to come help


On stand by ;)

Huh! Good question. Being recruited by two organizations w/ three possible locations on both coasts... so I’m not sure where I’ll end up but almost certainly moving out of my current position in St. Louis (after 20 years in here!).
And there is lots of things yet to consider.

Don't forget to consider the the $$$ and the benefits of DFW for Kate....
As per the boat, I am not worried a sign in bonus will take care of that :winkingthumbsup"

Glad to hear that Swatski's Angles are okay with move. Look forward to hearing about it when the dust settles down.
 
With the dealer doing a leak down test I'm fairly sure this will confirm that the cylinder head / head gasket are good. The oil cooler should be able to be disconnected and checked with a pressure test to make sure its not leaking. The exhaust manifold could potentially be checked with an infrared temperature gauge Im not sure if the aluminum will sink the heat away and equalize the reading but it should have a hot spot due to the gasses entering the water jacket

Photo compliments of @fairpilot with the potential hot spot areas marked up If the boat is run for a short time with no water you may be able to measure these areas and see if you get a spot that is much hotter identifying the potential issue. Since 90% of motors that the dealer works on are jet ski motors I don't think its as prevalent with one motor your more likely to notice the cavitation it gets masked with two motors so damage to the manifold is not that prevalent on PWC motors. The manifold pictured below is upside down in relation to its mounting position on the boat it also makes sense that the breach points that were reported are at the top air bubbles rising to the top not allowing proper cooling and the water jacket gets roasted from the exhaust gasses. That is the hottest part of any motor on other types of motors its not uncommon to actually see that area glow red

View attachment 108275
Cambo,
in your picture of Fairpilot's exhaust manifold, if you did have a breach like that, wouldn't you get a tremendous cloud of white smoke coming out of the exhaust or at least an increasing cloud as the crack widened or do you think there is so much water intrusion it cools the manifold down enough that it doesn't turn to steam?
 
@swatski I am sorry to hear about your problems. I consider myself an experienced rookie with these boats, so cant give you any advice better than you have already gotten! Hopefully the dealer will be able to diagnose the problem and it wont cost TOO much (all relative)! Glad to see you back on the forum....thought I had not seen posts from you in a while. Best of luck and keep us all informed.....small minds....oops I mean inquiring minds want to know :)
 
Could be same as I reported back in August with the below issue.

In the begining of August I was checking engine oil and found it milky on the port engine. Pulled the fill cap and it was covered in oil that looked like chocolate milk and was foamy. Drained and refilled the oil and filter on the lift 4 times til the oil ran clean. Took it for a quick test ride, put it on the lift, drained some oil and it was milky again.

Pulled the plugs and they looked fine which makes sense as the boat was running fine and no alarms sounded prior. Brought it to the dealer, they looked for obvious intrusion but finding none they pressurized the cylinder head and found a slight crack near one of the cylinder head bolts that was causing the water to get in. They sent pics to Yamaha and a week later they replied that they'd cover the work under warranty as it was a manufacturers defect. Took another week for the dealer to get the new cylinder head parts from Yamaha so all in all missed the month of August for boating this year.

So I no longer tell people that Yamaha engines are bulletproof. Hoping this was a one off fluke though I hold my breath now when checking the oil.
 
Could be same as I reported back in August with the below issue.

In the begining of August I was checking engine oil and found it milky on the port engine. Pulled the fill cap and it was covered in oil that looked like chocolate milk and was foamy. Drained and refilled the oil and filter on the lift 4 times til the oil ran clean. Took it for a quick test ride, put it on the lift, drained some oil and it was milky again.

Pulled the plugs and they looked fine which makes sense as the boat was running fine and no alarms sounded prior. Brought it to the dealer, they looked for obvious intrusion but finding none they pressurized the cylinder head and found a slight crack near one of the cylinder head bolts that was causing the water to get in. They sent pics to Yamaha and a week later they replied that they'd cover the work under warranty as it was a manufacturers defect. Took another week for the dealer to get the new cylinder head parts from Yamaha so all in all missed the month of August for boating this year.

So I no longer tell people that Yamaha engines are bulletproof. Hoping this was a one off fluke though I hold my breath now when checking the oil.
Thank you for that info!
I guess the only good news here would be that it should be discoverable with a pressure test (which would make a short "diagnostic Odyssey" of it - as @Betik would put it).

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So a quick update - as of this morning the boat is in a custody of Saint Charles Boat and Motor, in very capable hands of Jerry and Pat, the master Yamaha mechanic there. I'm told he's considered the best Yamaha tech in the region.
We will see what they find, hopefully, I'm super bummed but also kind of curious at the same time. Trying to be hopeful it won't be a whole new engine/long block (which apparently runs for some $12k from Yamaha... ouch!)


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Good luck. In searching my issue after it happened I was able to find a couple more of the same issue. Both cracks were right near the #2 cylinder head bolt. One dealer tore apart the entire engine before deciding to pressure test the head. The cracks were barely visible to the naked eye.
 
I like the way this guy thinks.

As one of what I would consider to be the best maintained boats on the site, it hurts too see you having problems. Getting lots of good advice here, the only thing I have to add is to NOT run that engine again until you get the oil changed out. Poor lubrication is the quickest way to ruin bearings in any machine, even beyond overloading them.

Good luck, with both the boat and the new venture.
Yes, I stopped the engine as soon as the "low oil pressure" alarm popped, there was no overheat, as far as I recall, wish I took a picture of the screen but I was too confused and frankly just about $hit myself when I pulled the oil dipstick and saw the froth... Fortunately I was just around the corner from my marina so just limped back on the other engine. I restarted the affected (Port side) engine once back on the lift with no issues just to see if it still works and to blow the water out.

I must say, I feel kind of glad (and very lucky) this has not happened in the middle of the Strait of Florida, or somewhere in the middle of the San Juan arm of the Lake Powell 100 miles away from Wahweap...lol. It would be a much longer trek back on one engine, lol.

I really hope we can get an answer, one way or another.
I like the layout, the size, and versatility of this boat but need to be able to trust it mechanically.

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Good luck. In searching my issue after it happened I was able to find a couple more of the same issue. Both cracks were right near the #2 cylinder head bolt. One dealer tore apart the entire engine before deciding to pressure test the head. The cracks were barely visible to the naked eye.
Yeah, I found this one, but I assumed it was only supercharged engines issue. Oh, well...

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