Oil & Fuel Clogging fuel filter - cannot figure this out

evomx971 · Jan 26, 2021

First post but long time reader here!

Mahindra 2516 HST (Mitsubishi 3cyl) - have owned this tractor since new in 2005. It has been a really great tractor and perfect for my small acreage. I can't say I've really had any issues with it... except ONE, and it seems to be getting worse.

The tractor will lose power and eventually quit running, especially when it's cold (but not extreme). If I let it sit for a few minutes it will re-start and I can get it back to the shop. If I put in a new fuel filter, it'll fire right back up and run like a champ for about 2 hours, then it will happen again. The fuel filter feels slightly "slimy" but otherwise looks perfect.

A little more backstory...

Years and years ago, I did have the filter gel over, so I do know what that looks like when it happens and this just doesn't seem like it's gelling necessarily. I use winter diesel from a reputable station and treat the fuel with Power Service. It runs great in warm weather and I think last winter I didn't really have any issues.

This fall, on a 60 degree day, it had the problem. First time it's ever happened on a warm day. Fuel filter was probably a year or two old so changed it and it ran fine for 2-5 hours lets say. Then, when plowing snow a few weeks ago at around 25-30 degrees it happened. Limped it back to the shop and talked to the local dealer about it. He thought it might be fungus. I drained the tank but didn't see anything that looked like fungus and the fuel lines flowed free. Cleaned the tank out really well, put in fresh winter diesel and treated with Power Service and biocide, just in case. I checked to make sure the gas cap was venting correctly. I always bleed the filter housing (two screws) when I swap the filter but the dealer said I don't really have to bleed it at the injectors. I have bled at the injectors to see if it makes a difference and it doesn't seem to matter if I do or don't.

No luck... will run great for about 2 hours, then run out of power or die. Let it sit a second and it will at least run enough to get back to the shop. Swap the filter and I'm running great again. Filters look fine to the eye. Nothing in the filter cup. I'm using Wix filters. I even have a make shift filter heater made from some old motorcycle heated grip wraps wrapped around the filter housing. I've tried with and without the "heater wrap" just in case that was causing an issue. I just don't think it's gelling necessarily. This year I haven't had to run it in anything less than about 15-20 degrees.

Any thoughts or ideas??? Love the tractor but this is driving me nuts.

My next idea is to try to find some "real" diesel or very low percentage bio. I ran the tractor during the winter for years and years without any real issues and it seems like it's just been getting worse and worse the last couple winters and now this year I can't keep it running for more than a couple hours without changing the filter.

I may also see if I can find some sort of larger filter to put in-line ahead of the stock fuel filter. Maybe something with a little higher micron? I think the stock filter is 30... maybe try a 40 micro pre-filter and see what that does?

Thanks for any ideas you all have!!!

jaxs · Jan 26, 2021

"I may also see if I can find some sort of larger filter to put in-line ahead of the stock fuel filter. Maybe something with a little higher micron? I think the stock filter is 30... maybe try a 40 micro pre-filter and see what that does?"

The more I read what you said,this is something I thought i might try. In addition,change fuel source and continue with algecid treatment. Algae is like cooties and bed bugs,you can continue burning your undies and bedding but until the hotel where you stay once a month fixes their problem,the problem never ends. Once agae get's established,it can feed on new fuel added to tank indefinatly. Your supplier (or one of your suppliers) might have algae in their storage tank. Is it possible the lift pump is on the verge? While adding another filter,maybe a pressure guage can be added.

LouNY · Jan 26, 2021

Another possible route would be a severe dose with a different biocide then using a small electric fuel pump,
pull from your tank push it thru a new large filter like would be used on a bulk tank pump and loop it right back into your tank.
Kind of a polishing system to get the fuel cleaned up. Many of the tank filter are 10 micron which would filter anything out.
Is your filter kind of slippery or greasy feeling when you change it. It could be a paraffin build up, once the paraffin crystalizes
in fuel it can be hard to get it dissolved again.

jaxs · Jan 26, 2021

"Kind of a polishing system to get the fuel cleaned up." :thumbsup:

evomx971 · Jan 26, 2021

I completely drained the tank, cleaned it out with gasoline, let it completely dry, then refilled with new winter diesel treated with power service and biocide. Plus I can't see ANYTHING in the filter so really not thinking it's fungus. If the fuel isn't clean, I can't think of a way to make it cleaner. Definitely thinking about the pre-filter though.

What causes paraffin build up? The "bad" filters look fine but definitely have a slimy feel to them.

evomx971 · Jan 26, 2021

Follow up question: my dealer has recommended I treat the fuel with double the recommendation of Power Service so I generally have. Is it possible it's too much Power Service?

LouNY · Jan 26, 2021

When diesel gets cold the paraffin will form crystals,
those crystals are difficult to get dissolved and blended back into the fuel.
The power serve products are supposed to prevent this from happening,
that said I seem to recall that many of the anti jell products are labeled do not freeze.
They will for the most part not dissolve the paraffin crystals.
Gasoline will usually dissolve it and many cleaners such as brake clean will.

Added; I usually do the double dose, supposedly it is not harmful.

RjCorazza · Jan 26, 2021

I had a ZD331 diesel mower that I bought used with 400h on it. In the summer I was having fuel starvation issues that seemed unsolvable. After a thorough cleaning I added a 2 micron filter, and an additional electric lift pump. I'm all for diagnosing problems, but sometimes a brute force approach works.
Ran great for the next 1200 hours before selling it.

Leejohn · Jan 26, 2021

You said you had good flow from tank and line to filter. With filter out and inlet and outlet lines off of filter blow air backwards thru the inlet and outlet of the filter housing. Then check flow out of filter housing, might want to check flow before even doing the above.