Oil Residue at air filter

ted_reshetiloff

Contributing Partner
I get some oil on the front of the engine around the air intake on the engine and was wondering if anyone had any ideas. I just adjusted the valves and am going to look at the crankcase breather in the valve cover to see if it is clogged. I noticed in some shots on this site that some peole have their breather line runnign into the intake and I amy do that but right now it just hangs on the side of the motor. It does not seem to drip any oil which makes me wonder if the breather is clogged. I dont get a bunch of oil just enough to make that pert of the engine look a little dirty...
 

u079721

Contributing Partner
Me too

Ted my Universal had a similar problem, which my mechanic told me was blow by (whatever that means). It was not supposed to be a big problem, and should have been solved by adjusting the valves, but it persisted even after that.

I pretty much solved the problem by routing the breather tube into the side of the air intake as you mentioned - which is an often suggested modification for Universal engines. After that there was a little bit of oil from the side of the air intake, but not anywhere near as much.

Some folks suggest that routing the breather tube to the air intake is NOT a good idea because it messes up the balance of air pressure inside the crank case. Perhaps one of the more knowledable folks on this list can comment?
 

rwthomas1

Sustaining Partner
Technically blowby is any combustion gas that escapes past the piston rings. Adjusting the valves shouldn't have any effect on the amount of blowby as the valves are closed during compression/combustion. The blowby gases escape past the rings and into the crankcase where they are usually vented from a high point in the engine such as the valve cover. Sometimes there is an oil separator integrated into the valve cover or inline in the breather tube, sometimes not.

Venting directly into the engine intake is done on many automotive diesels while old truck diesels commonly had a "draft" tube which is effectively what you are speaking of on the marine diesels. There is no problem venting the gases to the intake. The easiest way would be to simply lead the vent tube so that it vents into the intake air stream at the front of the engine.

The only time this can present a problem is when the engine has a very large amount of blowby. The excessive blowby can cause a runaway engine condition as the engine will continue to run on the "fuel" supplied by the oily blowby. This is pretty rare as that much blowby would cause hard starting and other issues that would alert you to a problem engine likely before it "ran away"

RT
 

hodo

Member III
Rob is entirely correct, on his explanation. I might also add, when you route the breather tube into the intake, it should enter perpendicular to the intake air flow, or more toward the engine. If the hose is facing into the intake, against the air flow, you could possibly pressurize the crankcase, forcxing oil to weep past seals and gaskets. I did it to my universal on the e30+ with good results. Harold
 

u079721

Contributing Partner
hodo said:
Rob is entirely correct, on his explanation. I might also add, when you route the breather tube into the intake, it should enter perpendicular to the intake air flow, or more toward the engine. If the hose is facing into the intake, against the air flow, you could possibly pressurize the crankcase, forcing oil to weep past seals and gaskets. I did it to my universal on the e30+ with good results. Harold

That's good to hear about the air direction, since what I cobbled together was to drill and tap the backside (aft side) of the air cleaner-intake for a nipple, and then attach the breather tube to the nipple. Which would have been across the flow. It would also explain how it is possible to mess things up by hooking up the breather tube to the air intake. Interesting.

Now that you mention about the rings that does sound familiar. I now recall that the mechanic was surprised that I had any blow by, since when he pulled the cylinder head to decarbonize the engine (thanks to the PO running the engine WAY over-propped) he found the piston rings to be in good shape. Oh well.
 

footrope

Contributing Partner
Blogs Author
Air Filter?

Interesting thread. My breather tube goes into the body of the "air filter" with no seal around it. It fits good - not loosely, not tightly, just right. 90 degree angle, too.

The air filter has no element, though. It has a large bore screen riveted over the rectangular inlet. Keeps out cats, dogs & small children. I discovered this a few weeks ago when I replaced the mangled piece of 2" rubber pipe that connects it to the intake manifold (airbox?). I had one of those uh-oh moments. I put it back on, reasoning that the engine shop would have charged me for a filter if there was supposed to be one there.

So, is there supposed to be a paper or foam filter on the diesels?

I also discovered that your neighborhood Schucks and AutoZones don't carry 2" diameter hi-temp silicone pipe or hose. I had to go to a marine store and buy exhaust pipe quality stuff. Maybe a truck parts store would have a silicone hose that would work.
 

hodo

Member III
Normally, there is just the screen for the intake. F.Y.I., DO NOT use silicone hose where there are petroleum products coming in contact with them on a regular basis. It will cause them to deteriorate and swell up,then fall apart. This is a bad thing. I know a guy who used it on his fuel system, of course it failed at the most inopportune time. NAPA has the hose you need also. Harold
 

rwthomas1

Sustaining Partner
The described breather setups are just fine. No air filter needed on most boats. wheeled vehicles produce very fine abrasive dust from the action of the wheels on the surface thats why just about every land based vehicle has one. Having a filter on a boat engine is not really necessary since we don't have the same conditions. Walker makes the "Airsep" system that is fairly common on larger powerboats. Its really just a big K&N style oiled cotton gauze air filter. I think they are more common on turbocharged engines since they move more air and the turbo blades are very suseptible to FOD damage. It short, it is wasn't originally installed you probably don't need it.

I should add that silicone is NOT compatible with gasoline but it does stand up very well when used for coolant hose, air intake couplers, etc. The advantage is it withstands heat better. If I needed a short section of hose for the air intake a piece of radiator hose would work just fine.

RT
 
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ted_reshetiloff

Contributing Partner
Thanks guys. My question was more about oil accumulating around the air filter assempby than routing the crankcase breather there. Do any of you guys get much oil coming out of the air filter assembly? I dont get much just enough to make the engine look a little messy. I got my gaskets and other engine parts in the mail yesterday and going to put the motor back together tonight and will take a look at the breather box in the valve cover and see if it is clogged. Valves are all adjusted so we'll see how it goes. I would like to set the injection timing but my manual is rather vague on that procedure. I have a friend who is really good with diesels so I may get him to do it.
 

Emerald

Moderator
footrope said:
So, is there supposed to be a paper or foam filter on the diesels?

I've got two Yanmar diesels (2QM15 and 3GM30F). Both have a washable foam element as part of the air cleaner assembly. If you have just the mesh in the air cleaner, I would be suspicious someone may have thrown away your element in the past.

While our closed engine compartments are pretty clean compared to driving on a road, I would still recommend at least a simple foam filter that can be washed and oiled. Just not that expensive an item, and really cheap insurance against unnecessary engine wear from breathing dirt.


-David
Independence 31
Emerald
 

footrope

Contributing Partner
Blogs Author
Ted,

I have never noticed much on the front of the engine, but I'll take a more critical look at it tomorrow.

Thanks for the tip on the silicone, Hodo. I did not know that. I'll keep an eye on it. I'll also check the extra I bought and see if it is silicone, but at least the inner liner probably is. There is very little hose exposed to the oily airflow though.

I will flip a coin on the filter element - but also keep my eyes peeled for suitable foam piece.

Thanks,
 

wurzner

Member III
Ted,

I have the heat exchanger off my m40 that was actually make for the m50 (13"x3") that I was going to put on ebay. You name the price and its yours.

It is in very good shape, but I won't get it until next week when I pick up the boat following a repower. I can send you a picture if you are interested. I was going to keep it as a backup, but decided I have too much crap!

Email back channel if you are interested at wurzner@yahoo.com

thanks
shaun
 

rwthomas1

Sustaining Partner
No where to put a foam filter on my 5432. There is just a funny shaped intake "horn" that points to the bilge. I don't see how a filter could have been attached to this or where it would mount without obstructing the fit of the engine cover. Hmmm, maybe the later models have them and Craigs and my early models don't? Either way I don't see the point adding one to a setup like I have. RT
 

Emerald

Moderator
ted_reshetiloff said:
Torrenson Marine sells the foam element, and a lot of other parts. I would love to know of another source for parts with better pricing but at least these guys have most everything and ship quickly. Anyone know where I can find a new heat exchanger for my 5432 for a decent px?

http://www.marinedieseldirect.com/universal/shopping/

Hi Ted,

I haven't done a price comparison, but check out John Featherman of Featherman Enterprises. I have found him to be a very helpful and knowledgeable source of parts. His website is:

http://www.feathermanenterprises.com/


-David
Independence 31
Emerald
 

footrope

Contributing Partner
Blogs Author
Newer boat, different engine

Ted,

I just realized you had the 38-200. so our engines and engine installations are pretty different. For what it's worth, my no-filter-element air intake "horn" (good term for that thing) isn't a source of oil on the front of my engine. My engine is quite dry and clean as far as oil is concerned.

I hope you figure it out.
 
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