Engine went Kaput seven days into a three-week cruise.

[Hayden Watson]

I was seven days into a two week cruise when my Universal M25XP engine started acting up.
The symptoms are [in order of finding them not by importance]:
(1) Lack of cooling water which causes overheating if I push the revs and alternator too hard.
(a) Checked for strainer [clean]
(b) Impeller turning, i.e. not a spun impeller [impeller spins and all blades present.]
(c) Waterflow at the HX zinc. [very good flow]
As long as I kept the rpm below 1900 and the alternator dialed down from 150A to 20A it ran cool at 170º which is just below the thermostat temp of 180º. I was heading to Friday Harbor Marina at the time so I could do a deeper investigation when I got there.

(2) When I got to port and dropped to idle, the engine died which it has never done before. This happened every time I went to idle with it in gear. Hmm, this is troubling.

(3) Based on #1, I figured that the overheating problem was a plugged HX so I checked that. When I opened the engine compartment, I found that I had developed a significant oil leak. I checked the dip stick and had lost about 1-cup of engine oil in 1-hour of motoring.
I had been in the bilge one hour previous just before I checked the sea strainer and impeller and it was clean and dry. Now, I had the expected water that was spilled when checking the cooling but there was also a heavy oil slick on top of the water. I also could see where oil was dripping down both sides of the engine and both the rear motor mounts had pools of oil around them. I wiped up all of the oil from the engine that I could and started it to see where it was coming from. It appeared that it was coming from the #3 fuel injector where it screws into the head. As far as I know, this should not have any engine oil at this junction. The next morning when I had better light and a clearer head, I could see that it was bubbling out under the O-ring that seals the valve cover to the head. I unscrewed the oil fill cap and when it came loose, I could hear a puff of air come out as the Pressure escaped from inside the crankcase. I crankcase ventilation is provided by a 3/8" hose that I have routed to the engine air cleaner. This should make the crankcase have a slight vacuum so any pressure is too much.

So instead of continuing on my cruise, I needed to get Papillon back home which was 32nm from Friday Harbor without her diesel. To be continued.

 

[dLj]

Those are not good symptoms... But you know that....

dj

 

[Ralph Johnstone]

I'm gob-smacked @Hayden Watson . Sorry but I'm at a loss to even know where to start on such a plethora of grief.

Maybe I could start with a dumb question to get things rolling :

crankcase ventilation is provided by a 3/8" hose that I have routed to the engine air cleaner. This should make the crankcase have a slight vacuum so any pressure is too much.

Was the engine shut down when it showed the slight positive air pressure ? Or still running and showing positive crankcase
pressure ?

 

[higgs]

Is the crankcasr vent hose clear?

 

[Michael Davis]

Is the crankcasr vent hose clear?

That’s a good question. If the hose is clear and you have excess oil in the valve cover where it can be sucked into the air intake you could get a runaway engine. If that happens cutting off the air is the only option.

 

[Hayden Watson]

All of the above is true. The vent is open and it cannot carry the amount of blow-by the engine is making. All of that makes for a good possibility of runaway. For that reason, the few times that I have needed to fire up the engine, I have always had it in gear for the load of the prop and been prepared with a heavy plastic bag to cover the K&N air filter to choke it down if it wants to go. Fortunately it did not do that.

Yes it was running when it showed the positive pressure at the oil fill. The crank vent is feed to the K&N and is a freely open 3/8" hose. The next morning, I was able to detect a slight blue tinge to the smoke and it had the smell of oil rather than diesel.

The working theory is that it is eather a blow head gasket or a broken ring. The coolant is clean-green so that leads me to concider the rings to me the more likely colpret. Tomorrow I will be pulling the ingector nozzles and doing a compression test. Assuming that I find at least one clyinder with low compression, I will pull the head in the boat and try to determine if it is the head gasket or rings. If head gasket, I will do the repairs on the boat. If it is in the bottom end, it will come out so I can do a full overhaul. The engine has a bit less than 3000 hours on it.

 

[Hayden Watson]

I thing that the overheating and dying when idling in gear are likely due to loss in power of one cylinder which caused the normal loads that are not a problem to now be unsustainable.

Because of that, and the loss of oil and potential for run-away, I opted to bring the boat the 32-NM home without the help of the diesel My tender is a 10' inflatable with a 30-year-old Honda 2-hp. I used that as a pusher tug to get home. I times each leg of the trip to make maximum use of the currents and sailed or motor-sailed anytime I had any wind. Without wind or current, I could make 3-kts. Here is a short video of the first day [Saturday 9/12/26] from Friday Harbor to Coronet Bay. I covered the 20NM in 6 hours averaging 3.33-kts.

 

[Hayden Watson]

Leg 2 was from Coronet Bay just inside Deception pass to Oak Harbor. The current was adverse until noon so I sat around enjoying a good breakfast and watching my favorite Sunday Sailing YouTubes thanks to Starlink.

We made the last 18-miles from Coronet Bay back to Oak Harbor, getting there at 4:30. We left Coronet Bay at noon so that was 4.5 hours to cover 18-miles. That is a 4kmph average.

I raised the anchor at noon and headed out with just the beginnings of a current making about 3-kts over the ground. The current did not really kick in until I was passing Hope Island and at the same time, I was met with 10-kts of wind squarely on the nose. I raised the main and rolled out about 6-ft of genoa and sheeted both tight right on the centerline. I have found that with this configuration, I can motor sail with a tacking angle of 50º-60º with a VMG greater than what I can motor. I motor-sailed from Hope to Strawberry point with 10-nts of wind right on the nose. Even with current help, I could only make 3kts without sails due to the swell that was building up. I hoisted the full main and let out about 6-fit of the genoa and sheeted them both tight on centerline. I then motor-tacked upwind with a tacking angle of about 50º-60º. I was making about +4.5-kts speed over ground with a VMG of a bit more than 4kts so the effort of sailing was worth the effort.

As I got closer to Strawberry Point, the wind increased to +15kts and the wind against current really started to stack up the swell which caused the Honda's prop to pop out of the water too often for comfort. The channel is also pretty narrow at that point which would make sailing without the motor a real pain single handing. I ended up rolling in the jib and short tacking as close into the west shore as the depths would allow where the waves were much shorter but in this configuration, I was only making a VMG of less than 2-kts.

After Strawberry Point, the channel opens up so I killed the engine and headed out into the swell with a single reef in the main and about 6-wraps on the 140% which rewarded me with 6-7 kts GPS although the angle made the VMG not too hot. I also had 15-20 minutes where the wind just suddenly died. Sigh! Back to the Honda.

Fortunately, shortly after I putt-putted past Mariners Cove, the wind came in at 80º to my course from the south and I was able to broad reach the rest of the way to the entrance of Oak Harbor, ending up with a wing-on-wing run into the harbor.

 

[sailme88]

It's always difficult to DX from afar.. But from what you are saying, my thought goes to head gasket based on the oil. Often when the head gasket blows there is a loss of coolant as well. Coolant loss leads to overheating that you have. Very white exhaust can be present. Coolant can also mix with the oil.. So, it is possible to have less oil than you thought as the coolant mixed in and offered a false level. Had it not been for the oil loss, I would have suggested you check the prop. Rope, seaweed and eel grass can overcome the engine torque at low speed and stall the engine.

 

[Stu Jackson]

Hayden, epic salvation cruise, much to be admired of your ingenuity and perseverance. Good on you and congratulations on your return voyage. Thx for keeping us posted, when you have so many other things to do!

I once had one of the four studs holding my Oberdorfer raw water pump "disengage" from the gear case cover! Upon close inspection it turned out that the aluminum of the gear case cover that was holding the stud to it just disappeared! I repaired it with Devon, JBWeld wasn't strong enough. M25 engine. Reason for this story is this event spilled oil all over port side of engine. Just another thing to check.

Good luck, hope it's just the gasket and nothing deeper. Any engine questions, let me know, we have a ton of M25 series experts who I know with C34s.

 

[Hayden Watson]

It's always difficult to DX from afar.. But from what you are saying, my thought goes to head gasket based on the oil. Often when the head gasket blows there is a loss of coolant as well. Coolant loss leads to overheating that you have. Very white exhaust can be present. Coolant can also mix with the oil.. So, it is possible to have less oil than you thought as the coolant mixed in and offered a false level. Had it not been for the oil loss, I would have suggested you check the prop. Rope, seaweed and eel grass can overcome the engine torque at low speed and stall the engine.

I would agree with you if there was any loss of coolant but it is right where it was at the beginning of the cruise. On my system, the engine coolant is a part of the hydronic heating fluid and the level is regulated at the translucent surge tank in the cockpit locker. This means that the coolant inside the exhaust manifold tank is always completely full to the pressure cap. After I found the oil in the bilge, I checked the surge tank and the fluid was bright green and clear with no hint of cloudiness. On the M25XP, the pipe-pin that delivers oil from the block to the rocker is the only pressurized oil passage between the block and the head. It is located on the farthest corner of the block outside of the water passages and the pushrod openings. It would be highly unlikely for combustion gas to mix with it and not involve the coolant. As I said, the coolant is bright green and the oil is glossy black and neither have any cloudiness or milky appearance.

The over heating only occurred when I was working the engine hard and cooled down once the load was reduced. I think it was most likely due to loads greater than the working two cylinders could produce. The water in the exhaust "seems" like it might be a bit lower than expected but I believe that could be due to some plugging of the heat exchanger tubes which needs to be descaled every few years and is probably due. I spun the Oberdorfer impeller earlier this year and the engine ran for a few minutes before the engine got hot enough to alarm. During that time, there was no seawater moving through the HX so the salt water in it was heated above the salt precipitation temperature of 135ºF which cooks the salt to the tubes.

 

[Hayden Watson]

Hayden, epic salvation cruise, much to be admired of your ingenuity and perseverance. Good on you and congratulations on your return voyage. Thx for keeping us posted, when you have so many other things to do!

I once had one of the four studs holding my Oberdorfer raw water pump "disengage" from the gear case cover! Upon close inspection it turned out that the aluminum of the gear case cover that was holding the stud to it just disappeared! I repaired it with Devon, JBWeld wasn't strong enough. M25 engine. Reason for this story is this event spilled oil all over port side of engine. Just another thing to check.

Good luck, hope it's just the gasket and nothing deeper. Any engine questions, let me know, we have a ton of M25 series experts who I know with C34s.

Good to know about the repair to the treads for the Oberdorfer studs. Can you tell me more about this Devon of which you speak. I know of one fellow C30 owner who replaced the front timing gear cover this year due to stripped raw water pump studs. She found a used one in the UK and had it sent over at great expense.

In my case, the oil is not coming from the Oberdorfer because all of the free-range oil is on the back half of the engine. Front half is still nice and clean. There is also no oil around the injection pump. Most of the oil is bubbling out from the rocker cover near #3 injector. There is a lesser leak coming from the exhaust side of the rocker cover a few inches from the rear of the head. I say it is percolating because you can see bubbles of oil and air coming out of the gap. It reminds me of my visit to the LaBraya Tar Pits when I was a kid.

 

[Stu Jackson]

It is called DEVCON. Sorry I misspelled it in my last post. This is a representative sample close to what I used:

Devcon® 5 Minute® Epoxy Gel - ITW Performance Polymers

Devcon 5 Minute® Epoxy Gel is a fast-curing, non-migrating adhesive for filling gaps and bonding rough or smooth surfaces. Disappearing blue color for easy use.

itwperformancepolymers.com

I'll see if I can find the actual article I wrote for Mainsheet magazine over five years ago and let you know.

Can you tell me more about this Devon

 

[Stu Jackson]

Here's what I used and the hole it filled. Sent you a pm with the whole story writeup.
Devcon 10110

 

[Hayden Watson]

It is called DEVCON. Sorry I misspelled it in my last post. This is a representative sample close to what I used:

Devcon® 5 Minute® Epoxy Gel - ITW Performance Polymers

Devcon 5 Minute® Epoxy Gel is a fast-curing, non-migrating adhesive for filling gaps and bonding rough or smooth surfaces. Disappearing blue color for easy use.

itwperformancepolymers.com

I'll see if I can find the actual article I wrote for Mainsheet magazine over five years ago and let you know.

So, did you use it to glue the studs to the cover or fill, drill and tape new threads? timing gear covers are getting harder to find for these engines.

 

[Stu Jackson]

One stud, glued into the hole. No drill/tap. Here's the hole, last post showed the stud glued in.