A hole in air filter sponge

[Ken13559]

Now how did that happen? There's a big hole (size of air intake nozzle) on my 2GM20F sponge air filter facing the inlet nozzle. I now re-orientate the filter with hole away from nozzle. Engine runs fine. So anyone any idea what happened? Should I be expecting any problem?

 

[Don12364]

Anyone ever use one of those engine start sprays to get it going; ether etc?
Could be the spray chemical just dissolved the sponge.

Most yacht engines never see enough dusty air to need a sponge anyway and these filters are mainly for engines used in heavily contaminated areas so I wouldn't worry.

Might even have been a backfire through the intake.

Depends on whether the edges of the hole are dissolved away or burnt away.

 

[kloudie1]

The usual thing that happens with these is that the polyurethane (I think) foam oxidizes into a gritty mess. The real fix is to get a blank of air filter foam that goes in a lawnmower and take the old foam off the perforated base of the filter and replace with a foam that does not corrode.. Or you can buy a new Yanmar one every three years.. A friend’s Westerbeke was wrecked by a tiny piece of stainless (FOD) that embedded itself in the top of a piston and started a crack that eventually broke the piston in half. All because he didn’t have an air filter on the engine..

 

[Ken13559]

Maybe I go get some sponge foam for replacement. or those filter element used for cooker hood. would it work ?

 

[Claude L.-Auger]

Donalex is right, those engines don't get to suck in dusty air, but Claude is right also with is suggestion of getting a Yanmar one every 3 years. Ken, when you think about the overall cost of the filter over 3 years it, my own take is that it's real cheap insurance when you think about the cost of the engine. Good luck

 

[Ken13559]

Yes its true the Yanmar filter isn't costly but I suppose those missing parts gets suck into the engine. Don't know if it'll cause any problem. BTW this has been my 2nd filter over 8 years period. 1st one was totally lost. No sponge left whatsoever. Guess the engine ate it. Actually I was wondering if I could get paper filters instead. Hmmm, what preventive maintenance would you have for the air intake filter ? Perhaps "rotate" the filter once in awhile to have new side facing the nozzle ? I used to have a small Honda motocycle. The recommended PM for the sponge air filter is to soak in luboil and squeeze dry. I suppose this isn't what Yanmar would advise.
Really appreciate your sharing some ideas/knowledge with me.

 

[Benny]

Diesel engines do not normally backfire but it is common to find a black soot covering the air filter. I attribute it to oil and diesel fumes escaping from the crankcase, valve cover and fuel return lines. These fumes deteriorate the sponge material and pieces get sucked into the engine with no apparent ill effects. It is true that the air in the marine environment is not very dusty and the engine can be operated without the spong filter. Having said that it could happen that a particle of engine comparment insulation could work its way into the airway so it will be your call to replace it or not. I inspect mine everytime I change the oil and if light shines through it I place it back. I used to wash them in soap and water but have noticed they last longer if I leave them alone.

 

[Steve Dion]

Ken:

I do not think it is unusual to see the entire foam filter disappear. These are really built as a sound silencer so I would not be too concerned. Just replace it every couple of years as required.

 

[Ken13559]

Ok, so there should be no real concern. Thanks. Much appreciated.

 

[kloudie1]

Ken, ya really don't want to put that polyurethane grit through your engine.. It does not do the rings or valve seats any good!!! Best to change it out proactively as Steve and Benny suggest, or change with a foam that doesn't corrode. Some folks have modified a K&N cone shaped air filter element to fit inside the Yanmar housing, which gives ya a pretty good filter AND doesn't disintegrate into grit.
Happy Motoring

 

[Dan Johnson]

Hey Ken...

given your sailing location, you might try a motorcycle dealership -- on my Honda I replaced the paper air filter elements with the foam-wrapped wire frame filters made for desert biking -- the dealer may have the foam used for this.

Second thought -- you could possibly use the filter foam element found in many window or dual piece (Mitsubishi wall mounts) air condtioners. Several tight wraps of that stuff should catch anything that gets inside your engine box.

 

[Ken13559]

Ok, will try shop for K&N cone filters but I think that cost more than the Yanmar one. Aircon sponge filters? Got to check that out.

 

[SamLust]

That sponge Yanmar uses is a piece of crap. There's lots of ground up fiberglass floting around any boat. A diesel engine is a great vacuum cleaner. I put a large clamp-on K&N cleanable filter on the snorkle of the original air cleaner sponge housing. Works great and will last forever. Cost is not relevant because the K&N's last so long and can be washed. I have some that are 30 years old. No problem.

 

[Ken13559]

Sam, this K&N filter, does it have a housing or just the sponge element ? Any part number ? Thanks.

 

[SamLust]

Neither. They are oiled, corrugated fiber supported between screen grids. Washable. Available in an enormous variety of configurations. Were developed as lower restriction filtration for performance engines (motorcycles) and as forever replacements for original equipment filters. In the picture my K & N can be seen on the snorkle sticking off the air inlet bowl.

 

[Ken13559]

Sam, Thanks. Got the picture. Its cylindrical shape.

 

[Ron McCoy]

What's so damn hard about replacing the silly filter with a properly spec'd Yanmar replacement? You guys would look all over to do something stupid, rather then keep the diesel properly maintained. I just don't understand your "logic"? Next you'll be complaining that the engine injested something and it won't run properly. Jeez, my dandruff is up.

 

[kloudie1]

Well, in a nutshell, Ron, for me it is this way..
I want an air filter.
I don’t want a filter that changes to an engine wearing grit every three years
Yanmar’s filter does that
Therefore, I don’t want Yanmar’s filter.
I do not like protective devices that become dangerous as they age..
Yanmar specified a minimum cost item that would last through the warranty period. They are happy to continue to sell something that they make 300% on and as a bonus helps to wear out their engine..
Why not put a filter on that costs about the same and does not have to be replaced and does not wear the engine ??
My many years as a machinery maintenance engineer have caused me to be very wary of the OEM ..

 

[Ron McCoy]

It's your engine - press on!
I kind'a respect the folks at Yanmar. They've done the research and warrant the engine, I don't think they're off base on this one.
But, do what you wish. Good luck.