M35B Hisssss

[Sailing Amok]

Where you are indicating I'd first suspect either an idler gear or oil pump noise.  I don't know what would HISS, but I suppose that is in the ear of the beholder.  I couldn't hear the noise that you describe.

Thanks Ken. Should I be relieved by that, or more stressed out? Would the cyclical on/off intermittent nature of the sound ( which hasn't really come across in the video) be more indicative of the oil pump? It's not cyclical in any sort of predictable time pattern, but does sound like something pressurizing, or relieving pressure. I wonder if Kristina has any devices at the hospital that will let me record from a stethoscope. I'll look into it and see if we can borrow something, for the interest of the forum.

[KWKloeber]

Aaron

I'd much rather work on a pump or idler gear than a crank main bearing.  On the B engines the pump bolts to the back of the gear cover (instead of to the crankcase on the other engines,) and encircles the crankshaft (rather than being offset and driven by a gear on the crank on the other engines.)  The idler gear bolts to the crankcase. Both are "easily" serviced by removing the gear cover.  The only difficult part is getting the speed linkages/springs back together correctly (at least on the older engines, and ass/u/me the same on the Bs.)

That said, I don't know whether you should be relieved or not. I'm simply basing that on the location if the noise you marked, no other info - and of course noise travels through metal and can be as deceiving as tracing down a leak!  I have no experience with the noise because I haven't heard it, and no experience what a bad pump noise or bad idler gear of gear bushing noise sounds like.  But I'd consider there first, again only based on the location, nothing else.

If you have a Kubota dealer near you might run the HISSING question by it's mechanic - that engine is used in the Kubota F2400 tractor, for one.

Maybe also do an oil pressure check which might give you more information whether the pump is faulty.

I once had to replace a worn timing gear on a Buick V6 50 years ago but that was more of a constant medium-pitched whine than hissing.

[KWKloeber]

Aaron

A thought since it's not constant.
I'm 99% against playing Whack A Mole replacing parts but in this case the 1% exception might be to replace the oil filter assembly pressure relief valve to see if affects the noise.  That's an easy low-$ try and a faulty one might show up in before/after oil pressure checks.

[Sailing Amok]

Thanks again Ken, my thoughts exactly on the pressure relief valve. I was thinking I'd start right off the bat by replacing that, and also perhaps the oil pressure switch at the same time. I believe both are cheap parts. And I'm wondering if the Rice Crispies sound and engine bogging could be related to a switch which has been overworked by a faulty relief valve cycling on and off too quickly to light the light, or cut the engine, but just enough to cause the bogging the one time. I believe the relief valve should be a standard Kubota part, though, it looks like it's actually a series of 3 parts on the Kubota parts blowup (spring 1624136950, seat, valve 1624136930, ball 0771500201). I see from previous forum posts that there does not appear to be Kubota or any other equivalent for the switch, so I will just order one from the Canadian Westerbeke supplier. I think they are pretty cheap.
For the oil pressure check, I was contemplating installing a gauge permanently in the engine "room", and it looks like there may be an unused port, according to the  service manual. However the manual only discuses installing an oil pressure sender in that port. Would there be any reason I couldn't install a manual gauge rather than an electronic one?

[KWKloeber]

That particular normally open oil switch I've only found as Westerbeke - CD should also carry it.  It's unique because of the convoluted A & B series wiring.  I'm sure there's an aftermarket but I haven't matched it up (yet.)

It's here but the half-price cost says to me it's a knock-off.  The price is below dealer cost.
https://www.perfprotech.com/oil-pressure-switch-westerbeke-pn-037323-jhw37323/product/285237

I wouldn't want to run a remote gauge and have engine vibration transmitted to the copper tubing/fittings. What's the benefit over a pressure sender?  I've done a few panels that i added a pressure gauge to but always ran a wire.

When you mess in that location be sure to tie down the oil switch wires so there's no movement between the switch terminals and wires; i.e., no movement in the harness transmitted to the switch.  I can get into why but the switch WILL fail over time if it's left how Wb wired it.

[Sailing Amok]

I wouldn't want to run a remote gauge and have engine vibration transmitted to the copper tubing/fittings. What's the benefit over a pressure sender?  I've done a few panels that i added a pressure gauge to but always ran a wire.

Yeah, just the having to run a wire. As someone who's still learning, I tend to think the less I mess with the electrical on the boat, the better. Also, don't manual pressure gauges tend to be more responsive, and therefore better for troubleshooting? I would just be mounting the gauge in the engine room, not running it to the helm. So it would just be used for engine checks and diagnostics.

[KWKloeber]

I'm not suggesting a permanent gauge to check it, just a screw in gauge on a hose.  Like taking a compression check.

There's no single perfect answer when it comes to ANYTHING on a boat.  If you're not comfortable adding 3 wires for a gauge  then don't.   Every boat/owner has different circumstances.  I'm just saying what I would do.

Manufacturers' mentality baffles me that it's still ok to put idiot lights (idiot alarms) on cockpit panels.  Really?? Think about that.  It's only important to find out AFTER you have a problem?  ESPECIALLY oil pressure - operators need to know ONLY at the point there's 3 psi, not being warned that pressure was dropping 50, 40, 30, 20, 10 over the past couple of (insert hours? days? weeks? months?)  Why then have a temp gauge - why not just use alarm?  That, like no oil gauge, would reduce cost another smidgeon.

I suppose knowing fuel at every second is so much more critical than oil pressure.  CS and other mfgrs had it correct -  every cockpit had oil-temp-voltage (fuel is at the nav.)  Adding the oil pressure port to the As and Bs is one thing Westerbeke got right after it bought Universal; unfortunately CTY didn't get the concept.

(That sound was me stepping off that soapbox.)

[Sailing Amok]

I agree completely about the too little too late trouble lights. One of the first things I noticed when we started with Coral Wave was the lack of an oil pressure gauge at the helm. Not sure what Catalina's reasoning is for setting things up that way. I'd much rather have the fuel gauge at the nav station, and an oil gauge in its place if space was at that much of a premium. Seems like fuel gauges in boats are unreliable at best, and oil pressure is a more pressing concern. The reason I was thinking of adding a manual gauge in the engine room, since I was going to be putting one on temporarily for a diagnostic reading anyway, was that I have a series of hourly engine checks I perform during extended motoring. I take IR temp in a few places, check for leaks, check the bilge, and record/reset the barometer while I'm below deck. It would be handy to have an oil pressure gauge down there while I'm at it. Also, when there is any troubleshooting going on, I'm in the engine room and Kristina is at the helm.

[Ron Hill]

Guys : While you are pontificating about the lack of an oil pressure gage, I believe that most all automobile & engine manufactures have come to the realization that the oil system is a closed internal system and if the oil and filter are changed at specified times times - the system seldom (if ever) fails!! Therefor you don't really need an oil pressure gage!

A thought

[KWKloeber]

Aaron this is what the idler gear looks like behind the cover. 

[KWKloeber]

On a closed or open system pumps do fail (even with normal maintenance and it is irrelevant that is a closed system.)  Yes, on a highway you just coast to the shoulder and make a cell call to the auto club.  Easy peazy

The reasoning is so contrary to what gets drummed into every sailor to not be complacent with the odds of $hitt "seldom" happening.  "Famous last words" come to mind.
A myriad of woes on a vessel "seldom" occur but as sailors we guard against even the "never" ones with backups, we belt and suspender our systems.  We plan for the worst, the unexpected, and situations that will "seldom" happen.

Don't believe that the decision to exclude a gauge for the single most important fluid in our engine was based upon the weighing of anything but cost.  Universal didn't provide a port so CTY didn't spend $$ to add one.  Universal wired an illogical, fire-hazard harness and CTY didn't spend $$ to correct it.  It's about manufacturing the best cheapest vessel that CTY could.

Actually Universal DID provide an oil pressure port on the early M-25s. but did not wire it into the harness.

If ANYONE would believe that some cost is wise to eliminate, it would be JH Westerbeke, and it would not have provided (on its earliest engines to this day) an "unnecessary" oil pressure port.

The logical question, however, is why anyone would NOT want to be forewarned about oil pressure when the solution is SO SIMPLE that it's a no-brainer -- especially if the engine manufacturer makes it easy to do.

If, by how seldom I might need it, I "gauge" [ ] whether I need any safety system then my Lifesling is unnecessary.
Mon ami, how many times does an owner need to fire up in 5 seconds versus 20 seconds (I'll answer that: Never.)  Pontification is a matter of whether or not an owner sees the necessity of a safety system.

That's my story and Stickin Toit.

Everyone's Boat, Everyone's Choice.

the [oil] system seldom (if ever) fails!! Therefor you don't really need an oil pressure gage!

[Sailing Amok]

I've noticed that the number of gauges (yes, it's the Canadian spelling) on a vessel corelates to the level of risk associated with operating said vessel. Cars have fewer than planes, which have fewer than space shuttles. Given that we operate Coral Wave on the worlds second largest lake, surrounded by wilderness, are often the only boat in an anchorage, and operate frequently outside of VHF range, the more gauges the better!

[Ron Hill]

Guys : Maia Copa, Thanks Ken for the information.

I just never realized that there was that high of a simple oil pressure system failure rate!!  In my 45 years of boating and 75 years of driving, and 30 years of flying I've never heard of an engine marine or auto or aircraft (inline or radial) combustion or gas turbine that had an oil pressure failure because the oil pump died. Many an aircraft engine failure from oil starvation because the oil cap was not secured and the oil was slung out!!.

Guess I must live in a sterile environment !!

A few thoughts

[KWKloeber]

Ron

Two stories close to home...

I lost oil pressure on the Interstate in the middle of the night due to something being kicked up and hitting/cracking the oil filter bracket (which is in a vulnerable location.)  Had I had a gauge I might have done better -- (but I VERY luckily) the idiot light went on right before an exit and I was able to coast down the ramp and into a motel parking lot at the bottom (which also accepted pets!!)  Whew.

My brother was on the Trans Alaskan Highway and in the middle of nowhere (which is pretty much everywhere) the idiot light came on...  Had he had a gauge he might have been forewarned of a failing pump. 
How do you fix that to get home to NY when the only part you can get is a salvage pump (which bolts to the bottom of the block,) and due to a crossmember can't get the oil pan off without pulling the engine? 
You borrow a jig saw from the farmer, cut a hole right underneath of and replace the pump.  And put the cutout back in place w/ an oversize temporary patch w/ tapping screws and a lot of goop!!!!  Whew.

[Sailing Amok]

Aaron

A thought since it's not constant.
I'm 99% against playing Whack A Mole replacing parts but in this case the 1% exception might be to replace the oil filter assembly pressure relief valve to see if affects the noise.  That's an easy low-$ try and a faulty one might show up in before/after oil pressure checks.

My game of Whack A Mole seems to have paid off. Installed the new relief valve, and the hissing seems to have stopped! Fingers crossed it does not return, and that the valve really was the issue. The old spring was definitely a fair bit softer than the new spring. Also the ends of the spring were pretty worn looking. We also cut apart the oil filter, and there no signs of metal flakes in it, so I'm feeling pretty good about the state of internal bearings.

Unfortunately, now that the engine isn't hissing, it's become very evident that two of my injectors are super noisy. They do have a fair bit of diesel wetness around them as well, which I've been aware of for a couple seasons. I'm thinking the injectors are likely the cause of our engine bogging, and poor fuel consumption this season. One of them especially is hammering away compared to the others. So I ordered new injectors from Kubota and attempted to install them today. I hit a roadblock though. I can't for the life of me get the old "heat shields" out. I've tried mechanics pics, PB Blaster, gentle tapping with a hammer and drift. Nothing is budging them. All four are stuck. I didn't find any tips in the tech notes, or the forum, and it seems that the M25 doesn't have this part? The service manual suggests jamming a Philips screwdriver in to try to pull them out, but I'm hesitant to do anything that could create metal debris.