9/17/2005

Performing diesel purge

I looked around forever to find a decent resource for doing routine stuff like diesel purges, oil changes, fuel filter changes, etc. There's a little Mindspring Members page that helped me a bit, but the pictures are crummy . Naturally, I decided to do my own thing and document everything I did. I started with my trusty mixing bowl that I shoved under the car, under the large fuel filter housing. I tend to spill diesel fuel every time I do something. I'm sure I will like not having oily spills everywhere.

Then I got 4 feet of 1/4" fuel line at AutoZone for $4.20. It's made by GoodYear. There it is, hanging on the mailbox. After that, I busted out a can of Liqui Moly Diesel Purge, which smells like diesel fuel even through paper, ziplock bags, and all kinds of seals of its own. Not surprisingly, there's plenty of diesel fuel in it. And some steroids, I think. While you're at it, it's crazy not to pick up a primary (inline) fuel filter because all of your fuel lines are going to be unhooked anyway. You can buy an inline filter for about $4.00 at AutoZone. They are made in Israel by Deutch, which is a very crazy juxtaposition. For a while now, I was thinking about purchasing OEM filters due to their superior quality. I use gloves. I got cheap plastic gloves at a dollar store, and they work ok. Otherwise, you will smell like diesel. Even though you don't mind it, your girlfiend will. You are all set to purge your diesel and clean your injectors. Firstly, find your secondary (larger) fuel filter. Trace the cloth line coming in from the left. As you can see, it's turning into a thicker line going to the right. Trace that line to the end. Unhook line where indicated. Don't lose the clamp. The indicated end is going into the jar filled with Liqui Moly. Then you will have to unhook the inline fuel filter. We decided that you might as well change it. Check lines A and B for wear and tear. Replace them if needed by cutting off pieces of required length off your 4 foot chunk of 1/4" fuel line. Unhook filter C. When I unhooked everything, this is what I got: A - the 90 degree end of fuel filter went here. B - straight end of fuel filter went here. C - line that you traced from large fuel filter housing went here. Of course, I leaked diesel fuel on the ground. Only a small portion of the fuel was caught by the blue mixing bowl sitting under the car. Hook up the 4 foot fuel line you bought at AutoZone to the straight end of your new fuel filter, not the 90 degree agle end. Then attach the 90 degree angle end of your fuel filter to the line A from previous pic. The line you bought that's now attached to new fuel filter is going into the jar. I used a jar from Jif peanut butter. I hammered out two holes in the lid, a larger one for the thicker line, and a smaller one for our 1/4" line. Then I filled the jar with Moly, and stuck both lines into the jar through the lid. I then placed the jar in a spot where it could sit still like so: If you really do pee in the Jif jar, I really do pity you.

This is very important - make sure ends of your hoses stay firmly at the bottom of the jar. Here's another shot of how I arranged everything: Gentleman, start your engine. I let it idle for awhile, then yelled at my woman to come out and give it a little gas to about 20-25 on the tach while I was keeping an eye on the jar. When purge in the jar started to get low, I made sure that fuel lines stay at the bottom, then ran the car for another 30 seconds, then shut the engine off. The remaining purge went into the tank. Conclusion: Moly works! About 20 seconds into running my engine, it stopped knocking. Very nice. I then switched my attention to the used up inline filter: I noticed a lot of black stuff in it. Whether it's algae or something else, I had to see for myself what's inside: I then wrapped the fuel filter into a towel. The filter had ten more seconds to live. I proceeded to beat the filter in the towel with the hammer. The filter cracked, exposing cheaply-welded plastic halves: Inside, I found a little present filled with black poo: And another view: It's nothing but a plastic cylinder with a bottom and mesh walls. I bet folks at Mercedes-Benz dealership charge an arm and a leg to replace something like that. Mission accomplished. Your injectors are clean(er), and now we know what's inside the inline fuel filter.