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Solved Why change fuel filter?

Prefix for threads that contain problems that have been resolved, and there is an answer within the thread.


Moderator Emeritus
May 26, 2009
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City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
For some time now I've been advising others on this forum to change their fuel filter. Well, I finally decided to take my own advice! I have 151,000 miles on my Sport but have only driven it about 1,000 miles since I bought it this May. I bought it from a tow truck driver who impounded it for towing fees he charged when it was abandoned on the freeway. Not knowing anything about the vehicle's history, I assumed the worst regarding past regular maintenance. Since replacing my stock air filter with a racing cone filter I have been experiencing cold starting and post start/prewarm idling problems which I attributed to a leaner mixture due to increased air flow. I cleaned and eventually replaced the IAC valve, cleaned the MAF sensor and throttle body and reset the PCM multiple times. None of these actions corrected the problem.

My first step in replacing the fuel filter was to raise and then jack stand the left front of the vehicle. I did this to make sure fuel did not siphon out of the tank. Also, I don't like working under a vehicle and the more clearance the better. I placed an oil drain pan directly below the filter to catch any leaking fuel and made sure my drop light was not close enough to ignite any splashes. The safety clips were easily removed and I used a 3/8 inch release tool for the fuel connections. When I tilted the old filter to drain it I noticed that fuel did not flow easily. I installed the new filter making sure the arrow pointed toward the engine, lowered the vehicle and turned on the ignition to check for leaks. Since there were none I then started the engine to check further. On the previous morning the low was 35 degrees and the engine died several times after starting even though I tried to prevent it by stepping on the accelerator. On this morning the low was 32 degrees and the engine started, slowed but recovered on its own and then idled smoothly. I never had to step on the accelerator.

I decided to cut open the old filter and examine it. The photo below shows the post hack saw exercise.

When the hack saw initially cut thru the outer container, a rusty brown residue began leaking out.
The photo below is a close up of the filter element.

You can see the accumulated crud in the pleats.

I can't explain why my engine had enough fuel flow to pull 175 rwhp on the dynomometer and rev easily to 6,000 rpm but not enough to start from cold and idle properly. Nor can I explain why my engine idle increased from a too low 550 rpm to at least 700 after changing the filter. But I'm not one who argues with success!

After changing the filter I added two bottles of Techron fuel injector cleaner to the nearly full fuel tank. I used to own Volvos and Techron was the only fuel injector cleaner that Volvo endorsed. Some injector cleaners do a good job on the injectors but also cause carbon deposits on the intake valves. The fluffy deposits absorb fuel and cause rough idle and hesitation, especially in cold weather.

If you haven't changed your fuel filter in the last 30,000 miles I suggest that you do. I also suggest that you avoid adding fuel injector cleaner if your filter is due for a change. I suspect that a high percentage of early fuel pump failures are due to not changing the fuel filter at the suggested interval.



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Yikes....I bought a new fuel filter for mine, and tried to change it, but could not get those silly connectors offof the filter...I have the special ford tool to pop it loose, but it just would not budge...then I read in the Haines manual that the fuel filter is set "for the life of the vehicle" and needs never to be changed...

I think that is bull, but what is the trick to gettin the old one off....HELP....

Thanks for the pics....they sure inspired me...

The trick I've found that works the best for the connectors goes like this:

1. Insert disconnect tool as far in fuel fitting as possible. You probably won't be able to get it all the way initially, this is fine.

2. Push fuel line towards the filter while twisting and doing whatever you want to help break things free.

3. While holding the line against the filter, attempt to insert disconnect tool farther into the fitting. It may not slide in easily. You might still have to mess with things some to get it in there. But when the tool goes in all the way, you will know it.

4. Once tool is all the way in, pull the line off with the tool inserted.

Even on my 15 year old vehicle I got it off with relative ease once I figured out the correct process. Once you get one it's not hard to get the other since you know how it works. Once you have it off to check the little clip inside the fitting to make sure it's in there right and not bent up or something. The lines are pushed back on for reassembly, just give them a good tug backwards to make sure everything is seated properly.

The problem is gasoline will absorb moisture from the air, this moisture will rust the inside of the lines, the rust then clogs the filter. I would never consider the fuel filter a lifetime item. It's gotta clog at some point or another.

Thanks for the tips...I will give it another shot tomorrow....

Fuel filter change how to vid in the link in my signature. Explains how the tool works.

Not to be a doubting-debbie, but.....

In all likelihood, your pre-warm idle issues are ultimately caused by the lower intake manifold gaskets leaking. Now that the temps are dropping into the 50s and 40s across most areas north of the Mason-Dixon, the issue is starting to surface again. After you changed the fuel filter (which you probably did either on a warm day or in a warm garage) the idle was better because the engine was warmer, right?

Unless the lower intake gaskets have been done recently, the issue will likely be back as soon as the weather cools off again.

I'm having fits getting the filter off my '91, can get one side off but the other will not budge. Even a mechanic buddy that changes filters everyday can't get it off. He tells me the tabs inside the connector are messed up and the only way to get it off is cut the filter off and pry out the tabs. He said there is a kit to reinstall new tabs.? I'm affraid that if I cut the filter I won't be able to get the old tabs out and I will be SOL.

I agree with gijoecam your idle problem is more than likley your intake gaskets leaking.

Someone before me maimed one side of those connectors. How can I get that replaced??!

98 ford explorer sport OHV

I never could get my fuel filter off. It was the original filter, had 156,000 miles on it. I tried everything that was suggested. I finally just cut the old filter off at each end, as close to the filter as possible. Then I connected the new filter with 2 pieces of rubber fuel injection hose. Works like a champ.

I never could get my fuel filter off. It was the original filter, had 156,000 miles on it. I tried everything that was suggested. I finally just cut the old filter off at each end, as close to the filter as possible. Then I connected the new filter with 2 pieces of rubber fuel injection hose. Works like a champ.

That my next step

I purchased the stainless steel high press stockcar fex fuel line for my 2000 ford explorer 4.0 and cut the fuel filter off as I had the same problem with the filter, problem was the front line nylon had to use a insert into the nylon line then pushed the fex line onto the insert and clamped both end the one to the insert and the end on the fuel filter!

How difficult is it to replace the Fuel filter on a 98 5.0 explorer?

OK, I know this is an old thread but I had to change the fuel filter on my X and dreaded crawling under neath her and dealing with those PITA disconnects. So I bought this tool and it came right off. What a great tool for my collection

Where did you buy? How much? Seems like a charm for disconnecting the fuel filter. Last time when I did that using hand tool, it took me about 30 minutes.

I bought it from Tool Discounter for $12.94. There are no adapters to buy. It fits all Ford, and GM vehicles with fuel and A/C line disconnects. Just slide it on like in the video and your done, that fast.

I don't understand what the pliers tool can do that the small round plastic 5/16 line disconnect tool can't (note: the previously suggested 3/8 plastic tool is too BIG, so don't use that one!). I just changed my fuel filter 10 minutes ago on my '99 XLT for the second time since I've owned it and the plastic AC/fuel line disconnect tools worked great once again, it took less than 5 minutes to get both sides off. You essentially have to press it in all the way, spin it around 360 degrees a few times to loosen things up and then hold the filter with one hand/yank on the fuel line with the other and it will come loose.

You could also spray some WD40 in there beforehand to make the job even easier (personally, I didn't have to because I rust proof the truck every year and there was plenty of lube in there already). Having the front of the truck up on ramps is all the space you'll need to crawl in there... even if you're a big guy, trust me. ;)


(This is the kit I have. The 5/16 tool (gray color) is the one to use. You may have to "trim" the long portion a bit to fit inside some aftermarket filters on your second filter change, as I had to do today. It was too long and wouldn't slide in there, but was the correct length with an original Motorcraft filter on the first change. Go figure.)

That said, the first time I changed my fuel filter at 100,000 km (60,000 miles), there was an incredible amount of gunk that came out of it. It was deep black in color (almost like burnt oil) and smelled like fuel (no surprise there, lol). After the fuel filter change, my idle RPM's dropped significantly and the truck ran smoother. I also noticed a better fuel economy than before, so I like to think the fuel filter pays for itself in the long run with fuel savings alone, not to mention extending your fuel pump life... especially because the filter is under $10 to begin with!

Today, I changed it for the second time. Like before, there was no issues getting it off the truck with the plastic disc-like disconnect tool (I have a kit made by "Powerbuilt" that I bought for like $5 some 10 years ago - see image above). This time around, at approx. 90,000 miles (so roughly 30,000 miles since the last filter change), the fuel that came out of the old filter was dark/rusty brown, but a lot better & clearer than it was at double the mileage last time I changed it. Once again, the truck seems to run a little quieter and smoother than it did before.

In case anyone's wondering, I never put cheap gas into my Explorer... it runs on 87 octane Ultramar fuel consistently and never sees any other service stations. Occasionally, it will get the 92 octane fuel to clean the fuel system a bit, approximately once a year. An injector cleaner (either STP or Penzoil) is added every 6 months or so to keep the injectors happy, but that's about all. I therefore attribute the black gunk I saw on the first replacement and the brownish/dark particles in the fuel on the second to normal wear & tear of the fuel system. Bottom line is, the fuel filter is not there for the lifetime of the vehicle... unless Ford were to believe that the "lifetime" of the truck is somewhere at around 75,000 miles! (at which point things would be getting pretty clogged-up in there, based on what I saw pouring out of my old fuel filters).


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You use the pliers along with the fuel line disconnects. I tried to lubricate inside the lines, and moved the disconnect tool around but it would not go in all the way. So I ordered the pliers and with a little pressure on the disconnect tool the line came right off.