fuel filter change with diesel purge?

I am preparing to change the fuel filter for the first time on my 98 Jetta TDI. I was thinking of pre-filling the fuel filter with lubro-moly diesel purge, instead of diesel fuel. Is this a good way to kill two birds with one stone?

Also, exactly where does one pre-fill the fuel filter?

You would be wasting your diesel purge. It needs to be full strength to work properly, and would be quickly diluted by the fuel recirculation. Just use some D2, BioD, or fuel conditioner.

You fill where the thermostatic T connects to the top of the filter. A small funnel makes it very easy.

thanks.

is it okay to do this procedure while the engine is hot?

Change the fuel filter and fill it? Sure.

I changed my fuel filter 2 days ago... to "prefill" it, I hooked up my oil-sucker (for changing oil) to the outlet nipple of the fuel-filter. (one that connects to the clear section of hose.) I pullled a vacuum until fuel started to come out of the top of the filter. I then carefully/quickly swapped from the oil-sucker hose back to the injection-pump hose.

Engine started right up and there are no air bubbles at all in the clear section of hose.

I removed the water-drain from the "old" filter over a clear container to see what came out. About a TABLEspoon of water was present.

INTERESTINGLY: The fuel from the old filter was flourecent green in color. It looked just like the green antifreeze in my Dodge Truck.

What a disaster. I really botched that job. It got dark as I was working, so I did most of it with only a flashlight. I unhooked the fuel lines to the fuel filter and couldn't subsequently couldn't unscrew the clamp holding the fuel filter in place. I finally gave up on that and had to drive to Pep Boys (in my other car) to get a hose clamp, because the old one wouldn't screw back on. My car started okay and didn't choke or anything, but I could see air in the fuel line. How long will I have to run the car before the air gets out of the fuel line? Can it wait til morning?


I also got diesel fuel everywhere trying to fill the new filter. What's a good way to get this smell off my hands? Gojo isn't working.

I'll finish that crap tomorrow. Thanks.

The air will work itself out if the car is running. Give it a day or so.

Liquid laundry detergent does a pretty good job removing the smell from your hand. One TDIer I know uses the large detergent container with the push button dispenser as a hand cleaner. When it is "empty" of laundry detergent, he fills it with water. Enough soap remains to make a nice solution to clean your hands with. Just push the button and catch some on your hands.

Thanks for the tips, paramedick. You're nice.

I finished the filter change. Car never sputtered or anything, despite hours with the filter removed. (I did clamp the hoses, but it wasn't that tight.) It was really not a big deal at all, but apparently I didn't have the tools necessary to remove the bolt clamping the filter in place. It ended up taking hours, because of that. It's like I need one of those screwdrivers that has a flexible shaft so you can unscrew stuff in very tight places.

I drained the "water" from the bottom of the old fuel filter, but it smelled like pure diesel and seemed to be a lot more than just a tablespoon or so. So I stopped draining it. As far as I know, that fuel filter hadn't been changed in ~90,000 miles. How do I responsibly dispose of the fuel filter w/ diesel inside?

sameoldmike said:

How do I responsibly dispose of the fuel filter w/ diesel inside?

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Now you ask a hard question?

Not the environmentally friendly answer, but I bag 'em and trash 'em. I do drain the diesel into the oil recycle container.

sameoldmike said:

How do I responsibly dispose of the fuel filter w/ diesel inside?

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That is EASY here in Vermont, We have special places to take any envrionmentally unfriendly liquids. (Hazzardous waste disposal station) In fact, I beleive is is the LAW that I do not put used oil-filters into the trash.

Just last week, my wife and I loaded up my pickup with about 5 gallons of used oil, several gallons of used antifreeze, some 5-year old gasoline and some other various brake-fluid., paint and other yukky stuff... it all went to the "Hazzardous waste disposal station" and they took it for free of charge.

We also have to seperate metals, lumber yard waste, glass, plastics and several other materials before introduciton into the recycle-stream. In all cases, recycling is FREE of charge (if you pay a couple bucks for each bag of trash you take to the trash transer-station) Recycling is actually a GOOD deal all around... not only does it SIGNIFICANTLY reduce the amount of actual trash the household generates and costs less out of my pocket, it is good for the earth

sameoldmike said:

I drained the "water" from the bottom of the old fuel filter, but it smelled like pure diesel and seemed to be a lot more than just a tablespoon or so. So I stopped draining it. ?

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You should get about 1 quart of liquid out of the old fuel filter.... THEN hold the liquid up to the light (clear container) to see the water which migrates into a "blob" at the bottom of the container.

sameoldmike said:

apparently I didn't have the tools necessary to remove the bolt clamping the filter in place. It ended up taking hours, because of that.

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The day before I did my filter change, I removed the fuel-filter clamping mechinism and lubed all the moving parts and reinstalled.... that way, when it came time to actually DO the deed (of changing the filter) that part of the task was not an issue.

...but I am also one that washes my engine bay regularly, inspects all hoses and checks all components for leaks. I think nothing of spending a couple hours removing all ground lugs, cleaning up the metal surfaces and reinstalling. Every bolt/screw that I remove gets some antiseaze on it before reinstalling. I have even been known to replace rusted bolts with stainless-steel ones. I expect to have a long relationship with my TDI (minimum of 12 years) and treat it accordingly.

paramedick said:

The air will work itself out if the car is running. Give it a day or so.

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I am getting ready to change my fuel filter now. I have had a large air bubble in the clear line since the last time I changed it 10 or 20 thousand miles ago???

Bruce -- I don't know what to do with hazardous liquids in Baltimore. I think it's sort of ridiculous that this info isn't widely available. If those of us who actually want to do the environmentally responsible thing don't have the info, then the people who don't give a shat aren't going to help at all either.

Also thanks for the info on draining the water. So, when people suggest draining the water from the fuel filter w/ every oil change, that means taking the fuel filter out of the car, completely emptying it of its water and diesel contents, and priming it with clean diesel?

Funguy said:

I am getting ready to change my fuel filter now. I have had a large air bubble in the clear line since the last time I changed it 10 or 20 thousand miles ago???

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An air bubble is not unusual. If the car has been running well, ignore it.

That flourecent green could be mold. I use a fuel stabelizer I by at a fuel injector company, It's Stanadyne. My Jetta is only four years old and I've used it with no problems and increased mileage only 4oz. to a full tank. I'm averaging 39.9 miles in the city after 10 mile drive and in warm weather above 50 I notice the TDI engine because it's hotter gets even better mileage. I went to Canada from Portland Or. fully loaded averaging 70+ and got 53.5 if I remember correctly

Gemduo, this thread is almost 8 years old. Had me scratching my head, trying to remember posting here lol