does water and pure motor oil clog fuel filters?

[damac]

Long story short I'm having sudden issues in my 79 rabbit  with what looks to be restrictions/ pockets of air shooting from filter to pump inlet.  I have had good luck so far in my short 4 years experience with these old diesels.

I have no first hand experience with water and how it acts when passed through filter.  Does water clog the media, or does simply opening the drain allow you to get rid of what has built up?

Also a tankfull before my problem arose I ran out of fuel and dumped a gallon of oil in the car to get to my destination a few blocks away.  It sat all day and I filled up at the pump that night and the first 8 gallons used went find until the issue arose.

I can't troubleshoot the car until I get back into town thursday but I would like to know for future reference it those things can clog the filter?

Thanks!

[burn_your_money]

What kind of oil?

[theman53]

anytime something is run dry it has the potential to pull everything in that normally stays behind, or in a larger concentration. It could be your filter just got plugged from the stuff on the bottom of the tank getting pulled through. Where burn your money is going I believe, is if you dumped veg. oil in it, that has an even greater solvent power and could have loosened stuff more to further clog your filter. I would just spin another one on or put it on if MK2 style and see if it helps. I went through a filter an hour for a week and then a filter a week on my old MK1 when I put some junk in it. I did that for about 6 weeks before it got better.

[damac]

New diesel motor oil.

And I do use mk2 style filter with clear lines from rails to/from pump.  So all looks clear until the car is revved higher and all of a sudden big patches of air which I assume is getting worse when I try and rev the car out.

I definately have to troubleshoot it this weekend but was just curious if the media bloated or clogged from that stuff.  I'm guessing the water doesn't do much with lots of modern day filters for older cars having a water seperater with drain built in. 

[8v-of-fury]

Bay area Cali.. I can't imagine the temps are cold enough there to just plug the filter with thick oil.. (which I assume is 15w40 conventional diesel oil).

I did this exact same thing this winter (still winter here, -10c today all day.. ITS APRIL 3rd!), except I did it intentionally for fun. I had like 13L of old new oil. Just been on the shelf for so long it wasn't worth anything to anyone, so I dumped it in to mix with like 39L of diesel.. Clogged my filter because it was all 10w30 and it dropped temps the next couple days. Mind you the filter was like easily 4 years old, but it was clogged and frozen solid. I finally got it going again by taking a propane torch to the outside of the filter and having my little electric pusher pump work it out.

[8v-of-fury]

And then of course changing my filter... HAha there was so much water in there I had steam rapidly boiling out of the filter inlets.. lol

[bajacalal]

anytime something is run dry it has the potential to pull everything in that normally stays behind, or in a larger concentration. It could be your filter just got plugged from the stuff on the bottom of the tank getting pulled through.

I've always thought this was an old wives tale. The fuel pickup is in a fixed location. It draws from the same spot, at the bottom, all the time. So if there's something in that spot to get sucked in, it will, regardless of whether the tank has 10 gallons or 10 pints in it.

[8v-of-fury]

anytime something is run dry it has the potential to pull everything in that normally stays behind, or in a larger concentration. It could be your filter just got plugged from the stuff on the bottom of the tank getting pulled through.

I've always thought this was an old wives tale. The fuel pickup is in a fixed location. It draws from the same spot, at the bottom, all the time. So if there's something in that spot to get sucked in, it will, regardless of whether the tank has 10 gallons or 10 pints in it.

I agree, the flow current will always be right from the very bottom of the tank. I would think crud in the tank has more likely hood of getting sucked up when full, as there is more fluid for the crap to float up in as opposed to hovering near the bottom.

I figure if its loose enough to get picked up, its gonna on the first good corner you take and the fuel goes swoosh swoosh from side to side.

[bajacalal]

I agree, the flow current will always be right from the very bottom of the tank. I would think crud in the tank has more likely hood of getting sucked up when full, as there is more fluid for the crap to float up in as opposed to hovering near the bottom.

I figure if its loose enough to get picked up, its gonna on the first good corner you take and the fuel goes swoosh swoosh from side to side.

The only logic behind it, is that maybe, if there is something floating in the fuel, like bits of plastic or some solid material, it will get sucked in when the liquid goes below the fuel pickup.

[mtrans]

Motor oil go in and out fuel filter w/o prob.even used one,but of corse temp is factor.

[theman53]

I don't know if it is that way or not. I just know everytime I run somehting dry it causes problems, usually.

[damac]

Can anybody explain the layout of the mk1 diesel tank and how the inlet channel works?

I am assuming if that filter is just that and can cutoff fuel flow when clogged that the inlet gets fuel from the bottom of that assembly, inside the diamater of that filter unit?

If so I wonder what the heck is that loose white thin disc sitting right in the middle when I pull the filter out?  Its smaller than the diamater of the filter and it looks to just sit at the bottom with fuel in the tank.  I can easily push it out of the way with a screwdriver.

My filter has a hole at top of it so you can hook something on it and pull it up and out.  Its like a plastic cage with fine metal mesh on sides.  Bottom is completely open.

I am now curious if somehow my filter unit broke apart and that disc is under suction and blocking the holes the fuel inlet goes to?

[damac]

I just checked on my problem today and worked my way from back to front.

Filter had pine needles at inlet.

Compared flow by blowing through a foot of hose on it vs. a new dry and diesel soaked filter.  Had to puff my cheeks out and could barely blow through the old filter, could almost breathe normally through the new ones.

So I don't know if its safe to assume running the tank down constantly until the car shuts down had something to do with me disturbing the force on a tank that never had one issue in the jetta.

I am also still wondering about the tank layout because I can't see much through the hole and don't get why the screen was so clean and didn't keep these out of the filter?  Or maybe even though I blew lines out on install they just made their way.

I am not going to run the tank down anymore regardless.  I found that the last mark of empty allows me like 80 miles as it goes down and into the red, kind of like a reserve.  I will just use the empty as a sign to fillup with 8+ gallons. 

[8v-of-fury]

Teh red on an mk1 is a 5L reserve.. dunno what it is on an mk2..

My red zone gets me 80-100 km easy depending on driving style haha

[92EcoDiesel Jetta]

sounds like you had a clogged fuel filter. what's the deal with the pine needles? you may consider cleaning your tank out.

 to answer your original question, most diesel fuel filters will let the water through, unless its a aqua-block fuel filter, which is coated with corn starch, which swells when in contact with water, shutting off  fuel delivery.