GX 390 wet air filter

[ppea]

When i want to clean the filter i saw the missing material from the filter.I thing some of the particles entered into the engine.How can cause this?

 

[marnebcs]

After noticing that these wet filters are just for light to medium dusty conditions and hearing of serious engine damage on wet filtered engines, I decided to replace mine with a regular paper filter.
It will cause additional cost for sure, but I hated the mess on cleaning them seriously. It always took atleast 20 minutes and a half can of cleaner.

 

[ppea]

I knew that these wet filters are for heavy dust condition.It is possible that something pieces got into the engine,i saw some particles in the oil,but the engine run great.It's a good idea to change to paper filter?

 

[marnebcs]

I think so, a paper filter, is a "closed" filter while these oil filters allow a certain rate of pass through.
Look at the European Mann+Hummel filter company, when it comes to filtration they are the place to go. They state for their wet filters, that they're not suitable for very dusty conditions.
If you are just sickle bar mowing and snow blowing a wet filter may be fine, but flail mowing, tilling and sweeping may be a little too much.
For example Stump grinders, which use wet filters are known for premature engine damage.

 

[ppea]

when i think i make flail mowing every year aprox 4-5 acres and the engine is stil going strong.

 

[NibbanaFarm]

For automotive, mining and construction the oil bath filters used to be the gold standard for dusty conditions. This was a half century ago. I'm sure things have changed. I had a 1967 International Scout that had an oil bath air filter.

 

[Tinhack]

Look at the European Mann+Hummel filter company, when it comes to filtration they are the place to go.

Here in America, we already do. They're called Wix Filters. I just hate the M+H heavy claim of saving the planet.

 

[Jens767]

Hi ppea

Your original post and your photos made me curious of course, as I have the same air cleaner on my GX 390 engine as you.

Our filters are of the oil-bath type, and what I noticed on your photos, is that there are hardly any traces of oil to be seen. Could it be that there is way to little oil in the air cleaner case to make the cleaner work properly?

I just removed my air cleaner and made this photo for comparison:



As you can see, there are clear evidence of oil allover, and the filter seems to hold back debris as intended. I will of course need to clean it, and fill it up with new oil.

Here ia a photo of the air cleaner case, and also here debris has been filtered out:



When I clean it, I usually fill it up with new oil so the oil is flush with the horizontal „fins“ at the bottom of the air cleaner case. That has worked fine now for the almost 400 hours that I have used my tractor over the last 13 years.

A low oil level might not explain why parts of the steel wool is missing in your filter, but in your case I would replace the steel wool filter, and perhaps check the oil level more frequently in the future. If you don’t find the missing steel wool in the air cleaner case, there certainly is a risk that it has entered the engine, and that can’t be good

I hope that you haven’t had any problems with your engine due to this, and that with a new filter you will be up and running again soon


Best regards

Jens

 

[ppea]

In my photo the steel wool is already clean.I found the steel wool in oil.Probaly some steel wools maybe enter in the engine but the engire run perfect.I think to change the filter with the paper model.
In the first years of use my filter look like your filter and i clean 2-3 times per year until this year i found this steel wool missing and parts from it in oil.

 

[oughtsix]

When i want to clean the filter i saw the missing material from the filter.I thing some of the particles entered into the engine.How can cause this?

That doesn't look like "steel wool" to me. That looks like a wire link chain folded back and forth on itself. It looks like filter was dropped and the wire link chain separated at the folds. Zoom in with a large monitor and you can see the links in the wire braid. I doubt if any of the wire braid broke off and went into the engine. I think it just separated at the folds. I sure the heck would not have been able to discern this from the picture displayed on a tiny little phone screen.

The way an oil bath filter is supposed to work is the air is supposed to travel straight down at the oil pool at a high velocity. Just above the oil pool the air changes to the opposite direction and the rapid change in direction is supposed to whip the heavier than air debris out of the air stream by centripetal force allowing it to be caught in the oil pool. I don't know the design concept behind that filter.

I would switch to a paper filter.

 

[CliffordK]

I agree, it looks like those wires got mashed around a bit from mishandling.

Oil bath filters have been used for a very long time.

 

[Jens767]

Hi again ppea

Sorry, I didn’t realize that you had cleaned the filter already on your photos. A few weeks ago I cleaned my air filter also, and this is how it looked after I had cleaned it:



After 13 years and 400 working hours, it looks almost as new I would say. I am very puzzled how your filter ended up looking like it does

Looking at your photos, I think that there might be the risk that some of the missing material has entered the engine. As your engine runs great though, I wouldn’t worry too much, and the fact that you have found some particles in the oil, is evidence that they at least didn’t enter the engine.

Thousands of these types of engines are running without any problems every day worldwide, so I wonder why you would want to switch to a paper filter. It could be interesting to hear from some of our members who have done that, but it doesn’t help to explain how your filter got damaged in the first place.

If I remember correctly, you use your Grillo primarily for mowing, which I wouldn’t call very dusty conditions. My tractor has spent 90 % of its working hours mowing, and the air filter looks like new, as you can see.

To me it looks like your filter has been abused at some point in time, but as I have come to know you in this forum, I know that you take very good care of your tractor, and you certainly wouldn’t damage your filter with a screwdriver or anything like that. Have you perhaps had your maintenance done somewhere else at one point, and that someone else had his hands on your filter?

I would install a new steel wool element to see if that would solve the problem, as that would be the quickest and cheapest option, I think.

Thank you for sharing this problem with us, and I look forward to hear more from you on this topic.


Best regards

Jens

 

[marnebcs]

Again, when mowing most of the time, I would not worry about the filter, especially if it's not flail mowing on bare soil.
But when doing dirt work or lot of clearing jobs with the flail in dusty conditions, I wouldn't think twice switching to an enclosed paper filter. Dust is the enemy.

 

[ppea]

Update: I change the oil air filter with a chinese paper because the original filter was not on stock, but alot of dust passed through the filter.The original one can make a better job?

 

[leonz]

Your wire mesh element is damaged and needs to be replaced.
If the reservoir is low on oil the combustion air can and would
carry dust and debris that would impact the wire mesh and
cause it to break.

You need a new wire mesh insert or a complete oil bath filter.

Are you using 30 weight oil in the reservoir?

Are you using the engine on slopes?

 

[leonz]

Update: I change the oil air filter with a chinese paper because the original filter was not on stock, but a lot of dust passed through the filter. The original one can make a better job?

The oil bath air filter is better and will not clog as long as the reservoir
is cleaned and fresh 30 weight motor oil is added back to the full level markings.

The oil bath base is there to do one job, act as an oil reservoir and dirt collector.
The intake air is pulled through the top of the canister and then down where it impacts
the oil and the dust held by the oil and drops to the bottom of the oil cup.

The combination of the oil level in the cup and the mesh that the cleaner air passes through
to the combustion chamber is what stops the dust from damaging the engine and allowing the
full flow of combustion air to enter the combustion chamber of the GX390 engine.

Any fine dust that is not in the oil is trapped in the above it and drops into the oil when the engine
is shut down.

 

[ppea]

I don't use oil air filter anymore.I put a paper one but the original paper filter was not in stock i put a chinese paper filter.I order an original paper air filter.