Excessive Blow-by on Kama 554

[billbill1]

Rob, with your wealth, I can't believe that you don't have a complete engine or tractor for that matter, waiting to be used. In my case (poor as a church mouse) no more oil than it's losing, I would run it like it is. At the very least, it makes you keep an eye on the oil level before you run it everyday. As long as it has the power to do what you need it to do, a little oil useage is no big deal.

 

[Dave_Lilly]

Don't get your nickers in a twist Dave, remember that Rob has a completely different engine than do you. And anyway, I suggested the possibility of bad valve guide seals in my initial reply. Subsequent mention of condensation and emulsion was posted to hint that puffs of oily condensation might also be mistaken for oil fumes.

My response to you was was an attempt to explain how the "breather" works on Rob's FeiDong 495 engine. I've got the 3 cylinder version of the same engine in my KM454, so I think it's fair to assume I've got the same breather/fill cap. You said clean/replace breather, I merely attempted to explain why that particular suggestion was not applicable to Rob's (or my) engine. Note also I specified that Rob's breather/fill cap is 90 degree side-mounted on the valve cover. I assumed you'd understand that meant it takes considerably less oil accumulation under the valve cover for oil to get into his breather/fill cap than would on a top mounted breather.

And I made absolutely no allusion to water in the cylinders, so let's not go down that street right now - ok?. I merely stated that moisture accumulated under the valve cover will puff out the breather/fill cap in the form of (white) condensation, similar to the way white smoke (condensation) puffs briefly out of a cold muffler. And that moisture from any source will also cling to the inside of the valve cover - and inside the breather - in the form of emulsion. I wipe that crap outa mine every time I add/change oil

So miscommunication aside, we both actually are recommending that Rob consider the issue might be related to valve guides. As an after-thought, plugged oil return port(s) could cause the oil level under the cover to rise as well. In either case, I'd take the valve cover off for a looksee

//greg//

I feel that you are the one who has his knickers twisted, whatever knickers are. I don't wear knickers and even if I did I would not know how to twist them. Different engine or not, diesel engines all operate on the same principle, i.e., compression. Worn valve guides, worn or broken piston rings will allow blowby into the crankcase\valve cover which could cause oil to vent out of the oil fill\breather. If 3RRL does not have a faulty oil fill\breather cap the only logical explanation for his problem would be to check for worn valve guides or piston ring problems. Blocked oil passages would be kind of rare on an engine with 500 hrs unless 3RRL never changed his oil.

 

[Dave_Lilly]

Yes, I didn't take the cap apart for that photo.
What I referred to as "steel wool" is not really steel wool, it is probably the same as your mesh material.
I was thinking of taking the knurled cap off and adding a hose that went directly to the intake manifold so those vapors would get sucked in and burned up. Most of them should condense on the mesh and drip back into the valve cover.

If you are having blow-by problems I would strongly advise against adding this hose. If the blow-by problem gets worse your engine could suffer from a run away engine problem due to the engine actually using the blow-by oil to actually be used as fuel. Your only hope at that point would be that your compression release would kill the engine. Diesel engines can run on a variety of fuels, including their own engine oil.

 

[greg_g]

It's an easy job to remove the valve cover Rob, I think you should see what's underneath before doing anything more drastic. I cut a valve cover gasket out of black NAPA bulk stock in about 20 minutes. Matter of fact, made one for the breather while I was at it. Unlike those flimsy Chinese gaskets, your home-made replacement should durable enough to re-use a time or two.

I too am a bit leery of that synthetic 15W50. I second the suggestion to see if going back to a conventional 15W40 might not cut down a bit on the breather smoke.

If it helps, our engines are spec'd with a 22:1 compression ratio. Twenty two atmospheres is the neighborhood of 325 PSI.

//greg//

 

[greg_g]

I feel that you are the one who has his knickers twisted...

You're doing it again Dave. All I did initially was address your suggestion that Rob replace his breather. I thought you might be interested in learning what the TEPM version of the FeiDong 395/495 breather looked like, and how it worked. That should have been the end of it. You're the one who keeps straying down these other side streets. So let's just drop it, shall we?

Moving back on topic, I agree with your recommendation to Rob that he NOT procede with this return hose idea. Although having said that, some variants of the YangDong Y85 engine actually had a return hose. But it was between the valve cover and the crankcase, rather than between the breather and the intake manifold. Not sure, I think there may have been a check valve involved too.

My Mercedes turbo diesel on the other hand, does actually route valve cover emissions directly into the air filter housing (bypassing the paper filter). Perhaps heat from the turbo incinerates it, because Mercedes engineers were apparently not concerned about engine runaway from crankcase fumes.

//greg//

 

[Egon]

Some years back our gasoline vehicle engines had a hose from the valve cover to the the air intake before the air filter.

Just curious; when you remove the oil dipstick is there much blowby coming out the opening??

My thinking is that all just may be normal with the engine???

 

[greg_g]

My thinking is that all just may be normal with the engine...

Agreed. It just depends what Rob considers "excessive". Somebody already mentioned that all (off-road) diesels exhibit blowby to some extent.

I've witnessed the same wet spot on the valve cover, adjacent to my 395 breather. And I mentioned moisture before, because breather "smoke" from emulsion can exhibit the appearance of oil vapor. Emulsion in this case is a mix of oil/water/air that has been agitated to the extent that the oil and water will no longer separate. But fumes landing on the valve cover will stick - subsequently collecting dirt/dust - and engine heat will soon make the moisture content evaporate. When you open the hood, all you see is the oil and dust remainder.

Inspecting the inside of the valve cover will either confirm or discount any buildup of emulsion.

//greg//

 

[3RRL]

Egon,
I check the the oil when it's not running and didn't think of checking for blow by there while it's running.

Jerry,
I'll go back to Delo 15w40 to see if that helps.

Dave, from what you said and along the lines of what Jerry just said, if there is a possibility of a blocked oil passage (as a possible culprit) perhaps the 50w is partially responsible? It's a thought...

Greg, Roger on the 22:1 ratio. I don't have my book with me. I'll have to see if my Harvey Henson compression gauge goes that high? I think it only goes to 300 psi. Dang.

Bill, I was thinking the same thing. It might not be as bad as I suspected after all. I'll do what the other guys recommend and then report back.

 

[billbill1]

Rob, FWIW, I was going to change to synthetic oil at the next change, I have about 300 hours. Mine has never used a drop of oil and I am thinking that I might just stay with the Rotella T that I have always used. I would hate to fix something that isn't broke.

 

[greg_g]

I was going to change to synthetic oil at the next change... I might just stay with the Rotella T

Obviously we're interested in the results of Rob's return to conventional 15W40. But it's the 50 weight part of that synthetic he's using now that could be in question. If that turns out to be contributing to the problem - if one exists at all - you should be all right with Rotella's synthetic 15W40

//greg//