Clogged fuel filter

[arveetek]

We have an 02 GMC 6.6L here at work, and this morning the truck died and refused to restart after warming up for 15 minutes.

I checked the fuel, and drained the filter. What came out of the filter was a yellow liquid that I have not been able to identify. I first thought that someone had accidentally filled up the tank with gasoline, as the truck was filled up with fuel on Friday. However, after pumping some fuel out of the tank, it came out the normal green diesel. I pumped up the filter several times, and kept getting the yellow liquid.

I finally decided to replace the filter. Truck fired up and has been running normal since. I'm a bit stumped at what actually came out of the filter. Here's a picture of the fuel in question:

http://www.thedieselpageforums.com/photopost/data/500/medium/Diesel_filter.jpg

I drained at least 6 cups of fuel out of the filter, and they all looked that.

The general manager said he's been using a Lucas fuel additive. I've yet had a chance to examine this additive to make sure it's compatible with diesel fuel.

Anyone else ever experienced anything like this?

Casey

[arveetek]

I can say for sure it doesn't act like gasoline. We tried burning one of the yellow samples, and it did not want to burn well. Not volatile like gasoline.

Casey

[arveetek]

The Lucas additive says its compatible with diesel fuel....

[Kennedy]

I have a customer that I've been working with regarding some drivability issues with a known good tune on a LMM. I put my restriction gauge on his truck and it was pushing 9" hg. He had 7,000 miles on the filter in use so we changed it. I thought that the fuel looked a bit yellow to me as we poured it out, but did not pay close attention.

[Hillbilly Jim]

I am following this post with most interest.
Any biodiesel involved? I use commercial bio about I/2 the time for fillups and am always concerned for the health of my 2001. I always use additives in every fill up.

[arveetek]

No bio that I'm aware of. The only thing I can think of is that the GM has been adding healthy doses of fuel additives to try and cut down the smoking. (I think it's time for injectors.)

The only other thing I can think of is that we are loosing engine coolant. It's at the shop now checking for leaks in the hoses, etc. I don't see any way that coolant could end up in the fuel system pre-filter, though.

Casey

[Hillbilly Jim]

Vandalism?

[arveetek]

Vandalism?

That actually crossed my mind......

Casey

[Kennedy]

The Lucas additive says its compatible with diesel fuel....

Is it "compatible with" or is it "made for" diesel?

As Dr Lee once told me, gasoline and diesel are quite different and what works for one does not necessarily work for the other.

[Yukon6.2]

I pulled some strange liquid out of a snowmobile tank.
A friend of mine bought one for his kid's,came from B.C.He picked it up in the dead of winter,it had been frozen for weeks.He left it in my shop to thaw,i looked in the tank and there was a white blob in the bottom,we pulled it out wit a suction gun and put it in a clear bottle.If you shook the bottle it would mix with gas,but it would fall right out as soon as you stopped.Put it outside it was close to -40 and it would not freeze.Still acted the same.
Weird.
And the stuff in the cups... I watched a guy try to use a styrofoam cup to carry some gas,the bottom fell out in about 6 ft.
Thomas

[arveetek]

Is it "compatible with" or is it "made for" diesel?

As Dr Lee once told me, gasoline and diesel are quite different and what works for one does not necessarily work for the other.

I haven't had a chance to inspect the Lucas additive myself. I suspect it's one of their "one size fits all" formulas, and is not made specifically for diesel engines.

Casey

[arveetek]

I watched a guy try to use a styrofoam cup to carry some gas,the bottom fell out in about 6 ft.
Thomas

When I first suspected gasoline, I realized fairly quickly that it must not be, due to the fact that the styrofoam cups were not melting....

Casey

[DennisG01]

I actually think it might be normal. It looks a little "brighter" of a yellow to me, but whenever I've collected diesel from the filter purge, I've used clear containers. But, it does appear more yellow to me, than green. I think it might just be the extreme whiteness of the cup that is skewing the color. When you pumped the fuel from the tank, did you also put it in the same, white cups?