Thread: Dark brown sludge in old fuel filter

Over the weekend on the drive home after a show one of my B14s started hesitating and then it got worse, bucking like hell in all gears. It was awful. Made it home but the motor wouldn't start back up. Got some gas treatment and fuel injector cleaner from Autozone and also two gallons of fresh 93 octane fuel. Poured all of it into the tank, and after about 5 minutes of cranking it it started, but ran rough. Had to keep the foot on the throttle or it would stall. Eventually it started running OK and idled alright. Shut it off. (BTW about 20 minutes before this started I got cheap gas at some dump. I wonder if it was bad)

Just now got a new fuel filter from Autozone and installed it, but when I removed the old filter it literally poured out dark dark brown liquid all over the place and into the rags. Nasty. New fuel filter installed, car running fine. A way to test if a fuel filter needs to be replaced is to blow into the top end of it and feel if any air comes out the bottom. No air at all. Also new filter = weighs almost nothing. Old filter = weighs like 1/4 pound. I want to open it up somehow and see what kinda crap is still in there.

Made this thread to ask if anyone has had a similar experience with the old filter. I mean, how did the motor even RUN at all with that crap in the filter? And if so how many miles were on your old one? I think this one had at least 100k on it. :???:

that brown fluid that leaked out? we call that neglect. 100k on a fuel filter is way way way too long.

Umm, sorry got the car about 10k miles ago.

you didn't exchange all the filters, oil, plugs, plug wires, rotor, cap, and coolant when you got the car? That's day 1 stuff as everyone who sells cars is a liar and never does the maintenance they said they did.

I always change the spark plugs and do an oil change within the first week or so. I think the rest of that is overkill on a beater

If it were not necessary and were truly overkill, you wouldn't have made this post about how the fuel filter got clogged

Only thing that is debatable to me is the coolant, if its still green its ok most of the time. the rest critical items to the function of your vehicle that are both cheap and easy to replace. Upon receipt of a used vehicle, they should all be done because they may have never been. I even go so far as to do brakes and rotors within the first week as well. At least it was just the filter and not something more expensive like the pump. tiny cuts + fuel = not a good time.

The fuel filter sure in this case. Coolant I guess like you said it depends

Oh another thing I usually do is pull the valve cover and check for sludge. If I think it's necessary I'll do a GUNK engine flush and then change the oil. That GUNK stuff really works!

I'm approaching AARP status at a feverish clip and have had more cars than I can count, and have never just replaced a things on a newly purchased used vehicle just because. Definitely if something appears suspect and/or ancient or there is drivability issue, otherwise I just let things sort themselves out and call AAA when needed.

I'm going to guess that fuel filter was ancient and filtered until it could take no more, then shit out a bunch of garbage and clogged. I'd love to see a cross section of it. There might be something living in there.

How's that working out for ya?

On a used car, if there are any signs that regular maintenance wasn't done, replace the fuel filter. It is one of those things that people never replace unless they have to. On a used car, I usually throw a can of Gunk in the oil then do an oil change on principal, like you said, it's good stuff.

If you are feeling adventurous, you may want to pull the fuel pump next time you've got an almost empty tank and check for sludge at the bottom. If old gas sat too long, you may go through a few more filters.