Yanmar 3YM30 air filter

Oct 22, 2019
2
Beneteau 343 Toronto
As suggested by others I decided to inspect my air intake element on my Yanmar 3YM30. The foam was entirely missing, so I replaced it with a new one. I'm going to add this inspection to my annual list.

I noticed a very dirty piece of felt or something stuck to the end of the intake silencer. It peels off if you pull it. It was so dirty and cruddy that replacing it seems to make sense, but I can't find the part number and wouldn't know what to replace it with. The parts catalogue attached doesn't seem to be of help either.

Should I:
  1. Remove this and just use the air intake silencer without this piece,
  2. leave it in, or
  3. replace it?
Thanks for any insight you guys can give!
 

Attachments

Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
I noticed a very dirty piece of felt or something stuck to the end of the intake silencer. It peels off if you pull it.
Do you have a picture of this "piece of felt" ? Nothing like that on a 2GM 20F and nothing in the manual either.

Also, anything unusual going on in your engine compartment ? I see the interior of the filter support is corroded. It's galvanized and SHOULDN'T be showing any signs of corrosion. Mine is 21 years old and clean after 3,000+ hours. Have only replaced the filter once (at 15 yrs.) out of an abundance of caution as it still seemed in reasonable condition.
 
Oct 29, 2005
2,355
Hunter Marine 326 303 Singapore
After replacing the air filter many times I gave up. Just put the silencer back, don't bother with the foam/sponge. It'll breakdown with heat and time and be gummy and gets suck into engine. Anyway onboard boat air is almost always clean/dust free. So the foam/sponge filter does nothing.

Ken Y
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
I replaced my element about 4 years ago. Last Saturday I checked it and it still looks like new.
 

ToddS

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Sep 11, 2017
248
Beneteau 373 Cape Cod
Unless ........................... you have belt dust.

I'm at a loss as to why your filter element keeps disintegrating while mine holds up nicely. Things that make you go hmmmmmmmmmmmmmm ? :sosad:
In the first two years of owning my boat, I went through like 4 filters dissolving, and I only use the engine maybe 30-40 hours per year.... so I gave up and replaced mine with a KNN-style washable filter (from amazon) and that seems great so far after nearly 2 seasons...
 
Oct 22, 2019
2
Beneteau 343 Toronto
Do you have a picture of this "piece of felt" ? Nothing like that on a 2GM 20F and nothing in the manual either.
It was attached to my original message: link. It's hard to tell what it is, because it's black as soot! I can't find anything in the manual or parts catalogue either.

Also, anything unusual going on in your engine compartment ? I see the interior of the filter support is corroded. It's galvanized and SHOULDN'T be showing any signs of corrosion.
Perhaps. The boat is new to me. Is that small amount of corrosion a concern, or more an indication of something else going wrong?

I gave up and replaced mine with a KNN-style washable filter (from amazon) and that seems great so far after nearly 2 seasons...
I'm probably gonna do that too :) Wanted to give the stock foam filter a try first.

I'd still need to decide whether to remove or keep this dirty black sooty felt thing. I'm leaning towards just removing it.
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
It's hard to tell what it is, because it's black as soot!
OMG ...................... I hadn't realized what that was. Don't touch it again. Now go wash your hands :yikes: ! After you've done that, go wash your hands again :yikes: !

I couldn't tell you what that is ................... I couldn't even come up with a BS answer as to what that is. It's most likely something the previous owner applied. Whatever it is, you don't want anything like that even getting NEAR you engine. Deep six it.

Is that small amount of corrosion a concern, or more an indication of something else going wrong?
It in itself is not a problem. However, it indicates something UNUSUAL is going on.
 
May 17, 2004
5,025
Beneteau Oceanis 37 Havre de Grace
After 6 seasons and 400 hours the filter on our 3YM30 hardly had a dirty spot. I haven’t checked it yet this year but if I remember I’ll take a look at it this weekend and report back. Like Ralph says, it’s strange that some disintegrate so quickly and others are just fine.
 
Aug 12, 2020
53
Lancer 36 Pago Pago
The "felt thing" is most likely just residue from the disappearing filter and soot...quit feeling it:yikes: Some people do away with the filter entirely; cleaning up the wire frame and reinstalling will keep large debris from entering the intake.
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
I'd think engine heat would do it eventually.
You would think so.

Everybody's got roughly the same engine compartment temperature and yet some filters disintegrate and some do just fine. All part of a conspiracy, I'm sure :oops:.
 
May 7, 2012
1,338
Hunter e33 Maple Bay, BC
After 6 seasons and 400 hours the filter on our 3YM30 hardly had a dirty spot. I haven’t checked it yet this year but if I remember I’ll take a look at it this weekend and report back. Like Ralph says, it’s strange that some disintegrate so quickly and others are just fine.
9 seasons, 1,750 hours and have never needed to change out the air filter. Clean it every year with soap and water and that is it.
 
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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I wonder if that piece of felt is just meant to prevent metal-on-metal noise. mAYBE IT ALSO REDUCES RESONANT noises?
 
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Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
Picked up a few pictures yesterday of the current air filter after 5 years and 400 operating hours.

Air Filter 1.JPG

Air Filter 2.JPG

Interior metal backing and foam rubber in as new condition. No explanation other than maybe the engine doesn't use air o_O !
Welcome to "Sailing in the Twilight Zone :yikes:"
 
Apr 13, 2015
156
Catalina 309 Port Charlotte
Hey guys, that piece of felt is there to force the airflow through the filter media. Otherwise it will flow through the open end of the cone. It also does minimize metal to metal contact.

Dave
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
I think, maybe, that's what happens when you treat or clean the filter element with something that's incompatible with the material that it's made of. The crud on the felt seal or gasket is probably all that's left of the foam. Since the boat is new to you, who knows how long it's been like that or how long it took to disintegrate.

You might be able to make your own felt "seal" for the inside of the cover.
 
May 17, 2004
5,025
Beneteau Oceanis 37 Havre de Grace
As another data point, this is my air filter after 7 seasons and 410 hours -
CD8C20BE-F370-4C99-8C50-E17054225DFE.jpeg


CE17738F-2E40-4226-AF66-D7D5FC563B75.jpeg


The lighting isn’t great in the picture, but in person I could see slightly dirty sections aligned with where I’ve had the intake pipe positioned. The rest of the filter material is pretty much pristine.

And this is the felt inside the housing -
ED5EF605-DD65-4870-A2BF-79D0604F4BF3.jpeg