Water in fuel or water separator in filter?

[ykobayashi]

Hi,

I had a hair raising fuel filter clog up in traffic in downtown LA today. No warning. It just came out left field and bam, the car starts losing power. I had been doing high speeds, hills etc. with no problems today before the clog up.

Luckily I had kept my two tank WVO system filled with a few gallons of diesel. I no longer grease. I flipped the switch and vroom my anemic engine came back to life. I had been flooring it to get to twenty mph when things started falling apart.

All I can think of is I had just filled a full tank at circle K this morning before setting off. Did they pump water into my tank?

In the past clogs usually give me some warning. Like no power at high speed or on hills. But this thing just hit me out of the blue. The car was doing great five minutes before it started stalling. It didn’t feel like an air bubble, just a smooth power loss.

So I started wondering, do the OM617 fuel filters have a water separator? I recall my old VW had a drain on the bottom and the MB filter does not. Am I supposed to dump out my filter periodically?

Man what a sinking feeling as my car lost power while I was boxed in at 5 mph in traffic. Thank goodness I was too lazy to remove my auxiliary fuel valve and filter after quitting WVO.

Tomorrow I’ll tear into it and check the contents of my filter. Wow I’m so happy I didn’t get stuck. Right on the heels of my stuck fuel sender resulting in a tow.

[Diseasel300]

If you switched tanks and the power loss went away, that suggests a plugged tank strainer, not clogged fuel filter.

[ykobayashi]

Ok. I just changed the stock MB filter. My strainer had a couple of black spots in it but nothing unusual or clogging. The car runs normally now on the filter that was clogged last night.

So I think my tank strainer is ok. I’ll say ok because when I pulled my sender last month it had some black spooge on the bottom. Like black grease. So yeah, I may be looking at a drain and screen Cleanout on the tank.

I poured out the filter into a mason jar and it came out all black. Not black like mud but black like somebody poured a table spoon full of used diesel oil in there and shook it up.

Stay tuned. I’ll update as it goes. My gut is I got a funky tank of fuel.

[Diseasel300]

Time for some BioBor or Startron. Seriously, don't let it get to the point that you have the "coffee grinds" in your prefilter.

[ykobayashi]

Yes I have coffee grounds. I’ll head out to get some biocide today. Will this cause a flood of crud into my filters? I guess I’m looking at 1) biocide, 2) drain tank, 3) clean tank screen and 3) new filters all round. That’s the proper way at this point sine I’ve confirmed the black goo in the bottom of the tank.

I went through the system and found a loose hose clamp too. I’m sure that wasn’t helping combined with a clogged filter.

Thanks.

[Diesel911]

The stock Mercedes Filters have no facility for water removal nor nothing special inside of them.
My Volvo diesel has the same filter as a VW Rabbit Diesel dose and it indeed has a drain at that the bottom and in addition is 2X as large as a Mercedes spin-on.

Some times if you die on the Road and the Filter has a drain on it you can drain out some of the crud an that will get you down the road a little further. More so if it is only Water. However, if it is solid crud not so likely.

Of the ones mentioned Startron claims to use an enzyme that eats up and dismembers the growth to the extent that they are so small they can pass through the Fuel Filter. That could save money and un-planned stops to change Filters.

There is at least one member with problem so severe that the Startron did not work well enough to keep him from having to change filters several times.

While obviously cleaning the Fuel Tank helps you still have infection and or dead material if a biocide is used in the tubing’s and hoses.

You mentioned going up hill. Going up hill causes crud at the bottom of the tank to shift around.

[ykobayashi]

Thanks 911. I was wondering if the filter had a water block polymer that would be choking off my fuel flow.

I looked at the contents of my filter in a mason jar and I cannot see water.

I drove down to Walmart and got some cheap diesel biocide. Diesel Kleen brand.

In the meantime I’m driving around with a new filter and a mityvac in the trunk in case I need to do a quick swap.

[vwnate1]

Welcome to my world .

This is why it's so important to use only CLEAR plastic intake screens ~ so you can easily see the coffee grounds (fungus) or water droplets the *instant* they begin to enter your fuel system .

My '84 Coupe actually chugged to a halt a few times back when first I bought it........

[ykobayashi]

Originally Posted by Diseasel300

If you switched tanks and the power loss went away, that suggests a plugged tank strainer, not clogged fuel filter.

Oh hey, I didn’t quite understand this first go round. My switch gear has separate filters. So I get a fresh filter when I switch over. This was critical in my WVO day’s because clogs happened when the oil would cloud up.

My tank strainer works. But it must be dirty given what I’m finding in the see through filter and what I saw on my fuel sender tip recently. I’m in for a cleaning.

Thanks for all the feedback guys.

[ykobayashi]

I’ve replaced filters, change lines, replaced hose clamps and finally I have the car running. I tried to systematically check the system by drawing fuel through with a mityvac and I never could find a clogged filter or line. I didn’t have any vacuum leaks...at least I could find.

Finally I broke down and pulled the lift pump. I took it to bits on the bench and I found that it had pitted plastic valves on the intake and exhaust. Not much but probably enough to hurt pumping efficiency. I noticed the bubbles in my clear lines danced back and forth a lot as I’d hand pump indicating the check valves just weren’t doing their job well.

I never drained the tank. On the list but I don’t think it is he problem based on my mityvac results to start fuel flow. Almost no vacuum required to get fuel up from the tanks and past the filters.

My check valves in the lift pump had a lot of wear marks that looked like pits and rings. The new ones were very smooth on the valve faces.

Hopefully this will do it. The car seems to run better and doesn’t go into starvation.

I noticed one of the barb fittings, I think it was on the output side of the lift pump had a rubber seal inside it. I didn’t want to disturb it. Is it an oring? I just put it all back together.