2013 f300xca - water in oil

[Humpty12]

First time poster, long time lurker. Hoping one of the old hats can chime in here.

2013 f300xca. Acquired boat and engines around 350 hours. Did the engine oil, oil filters, tstats, fuel filters (on board and outboard) gearcase lube, water pumps and housings at 400 hours. Currently at about 440 hours. No water when 100 hour service was performed. I did the work myself.

Noticed water in port engine oil last week. Immediately changed oil multiple times until oil ran clean. Had this done at a local shop due to time constraints. Asked shop to do compression/leak down test. All cylenders tested 160 ±/-, 5psi. Shop claims they did a leak down test, but haven't given me the numbers yet. Shop also claims that one of the timing belts was degrading. Had them replace belt while they had the boat. Going to seatrial soon. Shop claims no water appearing in oil while running on the hose.

Shop tech has no explanation for water in oil. Suggested that water may have entered via the exhaust due to engines being low on the transom. I like to fish when I have time, and sometimes it is rough out... I call bullshit on this explanation.

So, a few questions for the brain trust here.

1. Other than a possible warped oil pan, cracked head, bad head gasket, or cracked block, are there other "known culprits" on this powerplant that may cause this symptom?
2. Is it possible for a head gasket to blow and not affect performance, and the engine still passes a compression check? Any pro tips for validating this? I'm not afraid to tear the heads off and swap gaskets for peace of mind.
3. Anyone have any insight into whether or not it's possible to get water in oil on the exhaust stroke, if water somehow pushes back up the exhaust while running in sloppy conditions? How about while key off at the dock, if someone got overzealous with the hose pointed at the center of the prop?
4. Assuming oil milks up during seatrial tomorrow, any advice on next steps?
5. Note that I'm planning to check crankshaft runout by lifting on the flywheel, using a test dial indicator, on the engine that the timing belt was degraded on.
6. Last but not least, these went out of warranty in July. Anyone have experience negotiating with yamaha on "goodwill", assuming I have the infamous thrust bearing failure? Any pro tips other than to beg and grovel?

Interesting first post, I know, and I appreciate anyone who may have pointers for me. I have some experience turning wrenches, but I've always ran old two strokes. I hope this experience isn't indicative of what ownership of this new fangled 4 stroke power will be like, and I hope I haven't purchased time bombs...

Thanks in advance for any feedback.

[rodbolt17]

warped oil pan? seen it a few times.
cracked head? only seen it on the V8.
now lets put on da thinking helmet.
to get water in the oil via the ex it would have to go past the piston rings.
long before that happened it would most likely hydro lock and bend a rod.
seen that too many times.
most the time it is extended idling or bad thermostats.
on the belt, was it being chewed at the top?
Yamaha has no spec on crankshaft end play.
at least none they will share with a tech.

[pstephens46]

warped oil pan? seen it a few times.
cracked head? only seen it on the V8.
now lets put on da thinking helmet.
to get water in the oil via the ex it would have to go past the piston rings.
long before that happened it would most likely hydro lock and bend a rod.
seen that too many times.
most the time it is extended idling or bad thermostats.
on the belt, was it being chewed at the top?
Yamaha has no spec on crankshaft end play.
at least none they will share with a tech.

How does bad thermostats and/or extended idling contribute to water in oil?

[boscoe99]

How do bad thermostats and extending idling contribute to water in oil?

Good question.

[boscoe99]

warped oil pan? seen it a few times.
cracked head? only seen it on the V8.
now lets put on da thinking helmet.
to get water in the oil via the ex it would have to go past the piston rings.
long before that happened it would most likely hydro lock and bend a rod.
seen that too many times.
most the time it is extended idling or bad thermostats.
on the belt, was it being chewed at the top?
Yamaha has no spec on crankshaft end play.
at least none they will share with a tech.

It must not matter. The SM gives no tolerances on the crank shaft or the block for where the thrust bearings interface. Thrust bearings only come in one thickness.

Yamaha oh Yamaha.

[28Regulator]

I have a pair of F300XCAs with 1100 hours, made in 10/2013. Probably have your bearings. Timing belt on one has never been replaced and looks great. Timing belt on the other started scalloping at the top around 300-400 hours, and then pretty much maintained status quo until I replaced it at 1050 hours (with helpful tips from the crew on here). I've got some dust from the new belt after about 50 hours, but no scalloping so far.

Bottom line: I wouldn't be too worried about the timing belt/bearing, unless you have pix and it was really bad. Just keep an eye on top edges of both belts periodically.

No clue here on your water in oil issue.

[panasonic]

How does bad thermostats and/or extended idling contribute to water in oil?

I believe Rodnut is referring to the engine not getting hot enough to boil off the water that accumulates in the crank case from condensation.

I seen a bit of water collect in four stroke air cooled motorcycle engines after being stored all winter with many freeze and thaw cycles. But that was over months.

Merry Christmas all!!

[Humpty12]

warped oil pan? seen it a few times.
cracked head? only seen it on the V8.
now lets put on da thinking helmet.
to get water in the oil via the ex it would have to go past the piston rings.
long before that happened it would most likely hydro lock and bend a rod.
seen that too many times.
most the time it is extended idling or bad thermostats.
on the belt, was it being chewed at the top?
Yamaha has no spec on crankshaft end play.
at least none they will share with a tech.

Thanks for the response!

Ran the boat yesterday morning. Verified clean oil at the shop. Ran the boat in the ditch up to WOT for about 30-45 seconds, and no appreciable change in WOT. Engines ran very strong. Idled about 15 minutes to get from the ramp to where she could run.

Stopped and checked oil on the water. Oil was milky again. This rules out "water in oil from sloppy seas" as a cause (which is a silly thing to assume anyway). This also rules out "extended idle". Both engines rocksteady at 140' F. which seems to rule out bad thermostats (plus, water here is warm).

Regarding the belt, I did not see it myself. I'm told the tensioner was bad, and it was chewed at the top. I will be independently verifying crankshaft end play.

Currently suspecting a bad base gasket, oil pan gasket, or oil pump/cooler. Crankshaft end play testing is forthcoming after the holiday.

Shop is reaching out to Yama to see if they will goodwill some diagnostics time and/or parts and labor. If they will not, I'm bringing her home and going through the engine myself.

I'll continue to update this thread until I have a resolution, in the hopes it will help someone at some point.

[Humpty12]

I have a pair of F300XCAs with 1100 hours, made in 10/2013. Probably have your bearings. Timing belt on one has never been replaced and looks great. Timing belt on the other started scalloping at the top around 300-400 hours, and then pretty much maintained status quo until I replaced it at 1050 hours (with helpful tips from the crew on here). I've got some dust from the new belt after about 50 hours, but no scalloping so far.

Bottom line: I wouldn't be too worried about the timing belt/bearing, unless you have pix and it was really bad. Just keep an eye on top edges of both belts periodically.

No clue here on your water in oil issue.

Thanks for this. I'm hoping for the best.

I will say that my engines both fall into the affected range of the service bulletin 02013-009, which notes that the upper crankcase seal migrates out of position, and requires a "keeper" to be installed. That said, I can't think of any reason this seal would migrate, unless something was pushing it up.... The place I had survey the engines noted that there were no open recalls/service issues, but I will be inspecting the engines myself, assuming we can't get Yama to goodwill anything, and I'll update the thread.

[Humpty12]

Here are links to the five pages of the service bulletin I referenced above if anyone is interested:

Page 1 - https://i.imgur.com/UE4H8xe.jpg

Page 2 - https://i.imgur.com/O7Fcq7g.jpg

Page 3 - https://i.imgur.com/gHLp8Xu.jpg

Page 4 - https://i.imgur.com/oi3hofs.jpg

Page 5 - https://i.imgur.com/i1DhgOG.jpg

[Humpty12]

[boscoe99]

Thanks for this. I'm hoping for the best.

I will say that my engines both fall into the affected range of the service bulletin 02013-009, which notes that the upper crankcase seal migrates out of position, and requires a "keeper" to be installed. That said, I can't think of any reason this seal would migrate, unless something was pushing it up.... The place I had survey the engines noted that there were no open recalls/service issues, but I will be inspecting the engines myself, assuming we can't get Yama to goodwill anything, and I'll update the thread.

Oil pressure.

[rodbolt17]

that seal mod should have been done at the belt service.
does not take long not near as long as Yamaha pays.
that tech lost gravy money for the shop.
remember the intake has a cooler.
no oil cooler that I recall.
could be the oil pan,could be a head could be the powerhead adater.
could be a cylinderhead.gonna be a tough one to find.
but if the oil is turning white that quick yu can rule out idling or T-stats. typically that takes hours and it turns the oil a muddy brown.

[Humpty12]

Oil pressure.

This makes sense. In fact, I feel silly not considering that...50-80psi is a lot of pressure.

[Humpty12]

that seal mod should have been done at the belt service.
does not take long not near as long as Yamaha pays.
that tech lost gravy money for the shop.
remember the intake has a cooler.
no oil cooler that I recall.
could be the oil pan,could be a head could be the powerhead adater.
could be a cylinderhead.gonna be a tough one to find.
but if the oil is turning white that quick yu can rule out idling or T-stats. typically that takes hours and it turns the oil a muddy brown.

Not sure if it was or wasn't done. I trust the person who told me there were no open service bulletins on the engines. Presumably that means this was done before I acquired the engines.

Will be an interesting process to figure this one out, for sure.