5411 engine question:

[jrowan]

Hello all,

Does anyone else with a 5411 model Universal diesel know where the hose that exits up from the top of the valve cover is supposed to be routed to?
My hose was missing when I bought our boat, & it spurts oil up from this small opening. After it burped some oil around the valve cover I realized the hose was missing. I installed a new hose about 3/8" diameter & it appeared to route to a small empty hole at the inside right of the air intake "horn" or air box. Although I've noticed that oil now drips into the air box & down & out the adjacent wooden access panel & onto the cabin sole.
Try to make an improvement & it just creates another problem!
I thought about trying to install a PCV type valve onto the valve cover opening, or at least a paper type filter to catch this small amount of oil to stop it from making a mess. Before I installed the hose, it was sending oil droplets into the bilge & making a real lil mess. I thought that the oil pan was leaking at first, so it was a relief to find the culprit, but its still a nuisance.
Any advice?

 

[Stu Jackson]

Oil breather hose: http://www.pbase.com/mainecruising/image/80457594

and

http://www.ericsonyachts.org/infoexchange/showthread.php?10244-M25XP-Air-Intake-woes

 

[jrowan]

Thanks Stu,
But what I wonder is what to use to stop the oil from leaking out of that hose?
I understand that an engine has to have an oil breather so it doesn't back pressure itself, but was it supposed to run back to the air intake like that? It seems like its just creating oil for the engine to ingest from the air intake which can't be good for it. I saw the link for the K & N Air filter thread, but I wonder if that hose running from the valve cover would just soak the air filter element with oil? Mine is just the simple metal air horn with no air filter element installed at all. At the time I first saw it I thought, man that is lame, but then I thought that there's really no dust to get into the intake like a car has to deal with. That's when I thought of just installing a PCV valve like a car engine has.

 

[Jack - La Paz Mx]

Our 5411 engine has no air filter. The hose from the valve cover is routed to the air intake and held there by a small spring. Any blowby oil droplets are simply sucked into the engine. It isn't much as I have never seen oil at the end of the hose but haven't really looked. . There is no valve in the hose, simply a hose to direct the blowby to the engine air intake. Worn rings could increase the amount of blowby and possibly oil droplets, but the engine will eat those too. Tough little engine, little fuel used motoring, every three years I have to drain the diesel tank and put in fresh.

 

[anchorclanker]

Just be aware, if a diesel engine has excessive blow by, and the ventilation hose is connected to the intake manifold, the engine could run on the oil/oil fumes and become impossible to shut down. In extreme cases it could lead to a run away condition and further, catastrophic engine damage (holes in block). You would have to pull the hose off to get it to shut down, placing you in close proximity to something likely to explode if the engine reaches excessive rpm. Should this occur, you would be wise to remain in forward gear to control engine speed while you reach in to yank that line off. If you go into neutral, it could be all she wrote.

Many industrial diesels simply vent the breather to atmosphere, or use an oil seperator. Even with a seperator, excessive blowby can cause a run away situation.

I would take the breather on top of the valve cover apart and make sure the foam is in place and in good condition. Sometimes it gets forgotten, or deteriorates. Clean it all good and try it again. 2 cylinder 4 strokes create high pressure waves as the two pistons rise and fall. If the breather gets plugged up it can raise havoc. Make sure the oil is not overfilled, any excess could be whipped by the crank, exacerbating the problem.

Its looking like you have a major engine problem. Your window of opportunity for it to heal itself, if at all possible, is rapidly disappearing. The longer it runs in poor condition, the harder it will be to correct (your carboning up the rings further). You really need to pull the injectors and do some diagnosis/maintenance, check and/or adjust everything, before running it again. A hit and miss approach is not what this needs.

 

[jrhamp]

The hose is supposed to "hook" using a metal pin to the front on the air intake (you should see a small hole on each side of the air intake device).

I recently purchased a 1982 Cat 30 with a 5411 Universal..the hose was just loose hanging over onto the port side of the engine. I reconnected it after cleaning the air intake module and "foam" like filter.

I might add..I replaced the thermostat..which was visibly broken. Water does not flow immediately from the exhaust..it take awhile for the engine to warm up..the thermostat opens at 140 degrees (if I recall correctly).

Being a relative FNG on my boat, taking time to understand all the metrics results in confidence that "when you need it..it will function correctly".

Good luck/Randy

 

[Jack - La Paz Mx]

If you go to Stu's second link, down to the posting by "Mherrcat" you can see the "air silencer" cause that's all it is (ck Torresen Marine). The "spring or wire loop" to hold the breather tube is clearly visible at the horn or intake. The modification to use a K&N filter discusses punching a hole to direct the hose into the intake. Other advice is good and you might want to do a compression check.

 

[jrowan]

I appreciate the advice/ responses. To Anchorclanker, the amount of oil that escapes this hose is really minimal. Were talking about droplets after running for more then 2 hours at a time. This engine has already had a complete rebuild, and I had a through compression test done when purchasing a year ago. It runs great, it just allowed a small amount of oil to exit from this until recently completely open 3/8" hole at the top of the valve cover. You can imagine that there's a decent amount of oil that sloshes around inside that valve cover, especially when underway. I admit that I do tend to overfill my engines with oil a lil, as I think its better to be on the safe side then burn 'em up by letting them go dry. My engine stops by simply pulling back on the throttle until she stops by cutting the fuel. There's no way a couple of drops of oil could cause it to keep running on its own, let alone out of control? But thanks for the input. My biggest concern was allowing any oil drops to foul the air getting back into the engine air intake. By the way, a diesel engine could possibly seize from overheating, but I have never heard of one ever blowing up. There's not enough octane in diesel to cause an explosion necessary. I had a friend in the Navy, & he used to brag about how they actually threw cigarette butts into oil drums full of open diesel, & nothing would catch fire. Not that I advocate doing something stupid like that. Its is helpful to see where this vent hose is supposed to be routed. Its not in the Universal drawings for this engine in the manual. I hate when P.O.'s remove stuff that's important. You have to figure what's missing, & where's it supposed to go? Cheers.

 

[anchorclanker]

A few drops, no. I apologize, I think I have yours confused with another engine. Anyway, yes, they can and will run on engine oil, vegetable oil, propane, ether, anything thats burns really, and they can and will blow up on a good run away. VW issued a recall on the Rabbit Diesel years ago, because they were running on their own fumes and owners couldnt shut them off.

 

[Stu Jackson]

Its is helpful to see where this vent hose is supposed to be routed. Its not in the Universal drawings for this engine in the manual. I hate when P.O.'s remove stuff that's important. You have to figure what's missing, & where's it supposed to go? Cheers.

That was a GREAT description.

These ideas are not how the engines were first installed. All they did was what you described, just let it hang there! I doubt if your PO removed anything, that wasn't there for starters.

Others I know stick it into a small can with absorbent pads and change 'em out every once in a while. I do it with a small Excedrin bottle, just to ward off the headaches of cleaning up oil on the engine sole.

I want to do this mod, but the elbow coming off the top of the engine faces down, and I have to find a gorilla who can make it unscrew to go horizontal!

Anybody know any around here?

 

[jrowan]

Thanks Stu. I think that was the best idea yet. I like the simple approach.
Also if it is burping more then a few droplets I can see in a clear plastic bottle just how much. Its really a small amount of oil, about a teaspoon that manages to come out from the hole in the top of the valve cover. But as you know it only takes a few drops of engine oil to make a real mess in the bilge. Plus I don't want to pump oil residue overboard with the bilge pump. I do want to clarify though that this hole is at the top of the valve cover, not the intake manifold. This is oil that squeaks out the top of the engine, NOT back into it! That's why I really don't even want to route this hose back to the air intake horn. Doesn't seem wise to send oily residue back in there.
I just can't believe how simple, almost too simple, the Universal engine designs are.
I know they are a workhorse & truly reliable overall since mine is now 32 year old.
But it seems short sighted just to leave an uncovered, & unfiltered opening at the top of the valve cover. Common sense would tell you that sooner, rather then later it will leak oil and fumes. I mean, I thought Universal would have a higher standard for a marine engine, over a regular motor. But since they just converted tractor diesel engines for marine use, I guess that's what you should expect.
But I do like the idea of bottling any excess that escapes, Stu.
Also To Jack in La Paz, Mexico: When I heard that you sail your C 30 with a lil 5411 diesel all the way down there in Pacific waters it gives me hope that the 5411 isn't so wimpy after all! I knew that this motor was pretty small horse power when I bought the boat. But my C 30 was in such good overall shape mechanically & the price was just too good to pass up!

 

[Jack - La Paz Mx]

I believe the original intention was to route the valve cover breather to the intake as the loop for the hose is there next to the intake and my hose is even cut at an angle to facilitate any oil fumes getting sucked into the intake/cylinder and burned. As to sailing the 30 down to La Paz, the key is to do it in the fall before hurricane season. Its all downhill and warmer as you head south. Wouldn't want to go back up into prevailing winds/waves. We've been here now 14 years and all over the Sea of Cortez. The 5411 is small, but it's still a sailboat.