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Charcoal Box Cleaning

36081 Views 40 Replies 28 Participants Last post by  Corvinabee
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Allright, so in this DIY I will be showing you how to remove, clean, and reinstall the charcoal box from your Tib.

Do this if

1. While fueling up your tank, the nozzle pops a LOT and very quickly
2. Your gas tank overflows very easily
3. Other issues with filling/gas tank/fuel supply to engine

Difficulty rating 2

Only takes about 30 minutes but you will get dirty

Tools needed

1. Socket wrench with at least a 6 inch reach
2. 10mm socket (inside 2 bolts/screws)
3. 12mm socket (outside 4 bolts)
4. Pliers
5. Screwdriver (electric is nice) with a few inches of reach

YOU WILL BE DEALING WITH GASOLINE FUMES, DO NOT SMOKE OR DO ANYTHING STUPID WHILE YOU'RE WORKING ON THIS



Step 1

Crawl under the back of the car with your 12mm socket wrench and undo the 4 bolts on the metal casing. It is located directly under the license plate and in between the rear axle and the bumper. (not as difficult as it sounds just look)

BE CAREFUL The casing weighs a good 20 pounds with the charcoal box inside

There are 2 bolts circled, and 2 nuts with the bolt heads behind the metal housing (shown by arrows)



Here's a picture of the 2 nuts towards the front of the car; they are located above the rear axle



Once you remove the bolts lower the box to the ground so you can work with it from laying down on your stomach at the back of the car



Step 2

Remove the 2 10mm bolts (has a phillips screwdriver slot on top wont unscrew, trust me) using the 10mm head for the socket wrench. They are both located on the left under the 3 hoses. It holds the box to the casing.

The hoses are removed in this picture, just ignore it, take out the bolts



Step 3

Use the pliers to pinch the metal pincers holding the tubes onto their attachments and slide them down the tube an inch or so



You can see the metal piece moved over in this picture



Now you can remove the actual tubes from their plugs, just use the pliers, and pinch the tubes an inch out and just pry it off, takes some force but they will pop off

Careful! These tubes are connected to the gas tank so you will get a rush of fumes, just be careful to not breath them in too much | THEY ARE FLAMMABLE

The bottom tube (the largest) wraps around the box and plugs into some weird thing, pop it out of the side using the clamps and work the plug out of its hole.. (just look at the pictures)



When you get the tubes off, shake them out a bit and make sure there is no charcoal piece clogged up there, mine had a handful or so a few inches up

Step 5

Now you can actually remove the charcoal box and dump out the little pellets. Most effective method to empty it (for me) is turning it vertical with the 3 tube side down and slowly jiggle over a trash can



It holds almost a gallon of little pebbles and takes 5-10 minutes to clear all the way out, just be patient

Here's how much came out of mine, all that black is the little pebbles



At this point I decided to spray the box down with some water to rinse it off, optional I suppose

Step 6

Now we start the re-installation process

First, plug all the wires back into their spots and put the metal holders in their places (again, just follow pictures. They make more sense then my explanation)





The right side (with the big plug) is the tough part, stick the plastic plug in at an angle, then try and pop the piece into its housing, just push and wiggle. Takes some force



This is how far down the plastic plug should go, just push all the way



Second, screw/bolt the charcoal box back into the casing, same spots as before, right below the tubes

This is where I used the screwdriver with the reach, its easier to get to the screw hole below the tubes with the magnetic tip screwdriver, then use the socket wrench to tighten it

Step 7

Bolt the casing back on and you're done. Put on the nuts over the rear axle first and then put in the bolts in the back.

Here's a final pic before I screwed it back on, you can see mine is much cleaner :3_nosthum



Now make sure your car starts up fine (I don't know why it wouldn't..) and you're done!
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Re: DIY: Charcoal Box Cleaning

So after learning about evap systems I found out this is a really bad idea to do. Removing the charcoal will lessen your fuel economy and make other evap components faulty. The purpose of the charcoal is to store fuel vapors when the gas tank can't anymore. During closed loop operation (prolonged idle or crusing) the evap purge opens up the charcoal box to allow the vapors aid in fuel economy. The reason the charcoal hardens up and becomes clogged is due to over filling the gas tank which allows some fuel to flow down inside the charcoal box and harden the charcoal. The only real fix is to get a new charcoal box. Being the idiot I am I followed this before attending school and have now learned the purpose of the components. So please do not do this, go out and buy a new charcoal box
The EVAP system is more or less a closed system. A charcoal canister w/ or w/o charcoal should be irrelevant since the fumes are going to remain enclosed in the system regardless. All activated charcoal is is very porous charcoal. If you think about it, what good would that really do? It's just taking up volume and for what purpose? It MAY help retain the fumes in the canister, but gasoline vapors are tiny, volatile little thingies that are going to move wherever they please.
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Re: DIY: Charcoal Box Cleaning

the tibby im getting has the same problem, so should i go with the cleaning and putting back on or replacing all together ? i was prepared to follow the insructions until checking back and seeing Bonser corrected himself ... what to do now ? lol
Re: DIY: Charcoal Box Cleaning

The EVAP system is more or less a closed system. A charcoal canister w/ or w/o charcoal should be irrelevant since the fumes are going to remain enclosed in the system regardless. All activated charcoal is is very porous charcoal. If you think about it, what good would that really do? It's just taking up volume and for what purpose? It MAY help retain the fumes in the canister, but gasoline vapors are tiny, volatile little thingies that are going to move wherever they please.
I understand this. The sole purpose of the charcoal is to retain those fumes and aid in fuel economy as I said in my last post. You can have just the box without the charcoal which would hold fuel vapors but not as much as it would if it had the activated charcoal in it. I posted earlier trying to let people know that this could cause a drop in fuel economy, which is what a majority of people are trying to get these days. Sorry if it didn't sound that way.
Re: DIY: Charcoal Box Cleaning

Has anyone really checked their mileage after doing this work? If so, is the average the same, better, worse??

Has any other longterm issues popped up? Things like hard starting, running lean, CEL's. Since this has been around for a while, issues may have shown up now.
Re: DIY: Charcoal Box Cleaning

i just picked up the air filter that goes inside the charcaol box and im going to replace it as well as cklean iut the clogged up lines .... hoping it takes care of my fueling up issue
Re: DIY: Charcoal Box Cleaning

i just picked up the air filter that goes inside the charcaol box and im going to replace it as well as cklean iut the clogged up lines .... hoping it takes care of my fueling up issue


clean out ... sorry my typing is not the best
Re: DIY: Charcoal Box Cleaning

I got the same plomem when filling gas
:-(
Re: DIY: Charcoal Box Cleaning

So the correct way to fix it is replacing the complete canister? Or replacing just the filter will it work?
Re: DIY: Charcoal Box Cleaning

The EVAP system is more or less a closed system. A charcoal canister w/ or w/o charcoal should be irrelevant since the fumes are going to remain enclosed in the system regardless. All activated charcoal is is very porous charcoal. If you think about it, what good would that really do? It's just taking up volume and for what purpose? It MAY help retain the fumes in the canister, but gasoline vapors are tiny, volatile little thingies that are going to move wherever they please.

This is completely wrong.. the EVAP system is very much an open system, hence the need for a filter. There is a filter in place to prevent debris from entering the CCV and there is charcoal in the filter canister meant to absorb hydrocarbons during refueling and during thermal expansion of fuel vapors. The EVAP system is ALWAYS open with the exception being during a monitor "leak check", at this time the CCV is closed, a vacuum is drawn on the entire EVAP system, and the fuel tank pressure sensor voltage is monitored and compared to expected values. These emissions components are in place for a reason, and I don't care what some guy at O'Reillys says about this not affecting your emissions output.. they are some of the biggest spreaders of mis-information out there.

This procedure is just a band-aid, not a fix, and it's especially not a "cleaning procedure". If someone want's to do this, that's fine.. but people should have some understanding of what is going on when they decide to perform these modifications.

@Bonser27, you have it absolutely right.. *in theory*, removing the charcoal is going to decrease the amount of stored HC and increase the amount of oxygen being purged (and increase purge flow). This would be offset by an increase in fuel trim to maintain stoichiometric operating conditions, negatively affecting fuel econony.


Just some knowledge for people to make informed decisions....
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Re: DIY: Charcoal Box Cleaning

If I ever have this problem, it seems like it's just worth paying $150 for a new one.
Re: DIY: Charcoal Box Cleaning

Ok, So my 03 GT has the fuel filling problem. Seeing as removing the charcoal from the canister is not a good idea, what if I just banged the canister around a little until the clump broke up, cleaned out the tubes that may be clogged with charcoal, left the now loose charcoal inside the can and hooked it all back up? I think Im going to try this as it seems the clumping and hose clogging is the real issue here.
3
Re: DIY: Charcoal Box Cleaning

Welp, this is what I just did in the past hour. After assessing everyones DIY efforts on here I took a hybrid approach. I just went outside, got under my car, pulled the canister, and fixed the filling problem without removing the charcoal.

As soon as I pulled the hose off the canister that is labeled "tank", the hose that connects to the chamber in the canister where charcoal exists, charcoal fell right out of the tube indicating that there was indeed charcoal up inside the hose.

Next, after removing the canister from the hoses and freeing it from the car, I shook it to get an idea of the status of the charcoal inside. It sounded loose, but I could tell there were some bigger chunks inside. I banged the canister against a cinder block lightly a few times and continued to shake until it sounded loose like sand inside. After that, I decided to remove a small amount of charcoal from the canister, seeing as it spilled out very easily from the hole on the side of it, which probably helps clog the tube in the first place. I removed approx a cup of charcoal by shaking it over my trash can. There was still PLENTY left inside.

After I was satisfied with the canister I went back to the hose to inspect. Sure as ****, it was clogged at the first bend with pellets. Not loosely, but pretty packed in there. I broke it up with a screw driver and pinched the tube to free it all out.

Finally I put it all back together. The moment of truth was when I turned my car on, CEL still on, damnit! However, I drove to the gas station and put some gas in it, and squeezed that trigger full throttle, no clicking off!! So the canister and hose clean out solved that problem, was hoping for it to shut off my CEL too but that didnt happen. Either way Im super happy. Putting gas in my car was the bane of my existence.

My advice, pull the canister, shake it up, maybe empty a cup or so of charcoal from it, clean out the tank tube, put it back together, go to the gas station and be happy. :dance_bandwagon:

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This is a great DIY. One of the very best I've seen. THAnks
I tried to follow "ohthreetib"s solution, and removed a bit of charcoal making sure there weren't any clogged hoses/clumps left inside.. After going to the gas station, it's still clicking after every 15-30 cents worth of gas. Should I try removing more charcoal? Is this charcoal canister the only thing that can be causing the filling issue? Replacing the box entirely isn't really an option at the moment.
I'm having this issue right now. I'm not sure what has happened in this cars past since it's 16 years old and I've only owned it for 2 or 3 weeks now. We're also experiencing a weird burning smell after long trips that we think might be associated with this problem and we think it's coming from the hood area? Anyone know what that could be about? I'm trying to find a new filter since I don't want to sacrifice the MPG but isn't there something we can replace the charcoal pellets with?? This for example...

Rebuilding The Charcoal Canisters : How-To Library : The MG Experience
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Anyone have a part number for this? Cant seem to find anything about charcoal related to Tibs on O'Reilly's website.
I suppose I might try this this upcoming Saturday...if I do I will post my results.
Thanks I love my tiburon got it for vegas and It is in mint condition with few fixes but i got 2003 and I cant wait to finish few glitches... still planning on buying new one of these just couldnt take it taking so long to pump gas!!!! glad ya guys help us gals work on our cars never got bad advise yet!!! thanks again

Delila
So we just spent the last hour doing this, no charcoal came out of the box even after banging it on the ground, we put it back together and I haven't taken it to the gas station yet. But if no charcoal came out, what could the culprit of this problem be?
So we just spent the last hour doing this, no charcoal came out of the box even after banging it on the ground, we put it back together and I haven't taken it to the gas station yet. But if no charcoal came out, what could the culprit of this problem be?
You need to check the tubes that attach to the canister as well. Sometimes charcoal bits get sucked up into them and clog it from there. You can also change that filter while you're in there (fuel tank air filter is what it's called) though I haven't heard of it getting plugged up enough to cause a fuel problem.
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