2000 Buick Century Ltd. 3.1 liter Fuel Tank Removal

I want to replace my charcoal cannister. My D.I.Y. repair manual which includes my 2000 Buick Century 3.1 liter says that for my car it is next to the gas tank, which would be easily accessible. It is not next to the gas tank. It is above the tank requiring me to drop the tank. I didn’t look for what it said about removing the gas tank in my manual. it may not be accurate like the info about the cannister was inaccurate. What all is involved in a gas tank removal job for my car, can it just be lowered enough to gain room to remove the cannister or must I disconnect everything & fully remove the tank?

Are you sure you have the correct DIY manual? Just asking. When a manual says a part should be next to the gas tank, and it’s actually above the gas tank, that’s a big difference.

For what it’s worth… I wouldn’t try to remove or drop a gas tank myself. Too many variables, including the tendency for gasoline to explode unexpectedly.

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The manual implies that all makes, models & years in the scope of the manual are covered. Not all repairs to be made on all makes, years & models in the scope of the manual are covered though. The charcoal cannister removal procedure depicted here is obviously “typical” and instructions for this procedure for all years and makes and models of Buicks “covered” by the manual are not given.

removal of the gas tank shouldn’t be difficult, there are usually 2 long straps that hold it in place. There will be a bolt on the one end of the strap, and a notch/slot type of holder on the other end. (just above where your arrow is in the picture is a fuel tank strap.)
Gravity will help you remove the tank, so it should be as close to empty as feasible. This will also help keep copious amounts of fuel from sloshing around, which will make lowering and raising the tank more stable.
There will be wires and lines to disconnect, so make sure you have proper tools ready to go or you risk breaking a line or snagging a wire.

But- this is a fuel tank, so if you attempt this, you need to be careful. Keep flames, sparks, etc away, and have fire extinguishers on hand. Do this in a very well ventilated area- or even outside.

I can’t say for sure on your vehicle if lowering the tank just a little would be helpful, but I really doubt it.

There’s your problem.

You’re trusting a Haynes manual for repair information about your car.


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Yeah I agree. Unless you are using a factory manual or one of the subscription services, you need to treat the information like you would advice from your neighbor. I don’t spend the money anymore and hire stuff I don’t know how to do but have a whole shelf of factory manuals.

I’ve only removed one tank and the car was near new so now rust issues. I ran the tank near dry but it was still heavy enough to need a Jack to lower it and raise it up again. I don’t remember any particular problems with disconnecting things and the filler tube was all in one. Just be ready for the weight any connections and any parts that would need to be replaced, or just let a shop with a lift do it.

Fortunately, I have a plastic gas tank. Much less weight im sure. I once did a tank drop job on a '96 Buick Regal, and difficult access to the strap bolts was made much worse by rust seized bolts. You can be sure I coated the new bolts well with anti seize compound.

From what I’m seeing the canister is indeed above the fuel tank. May not have to completely remove the fuel tank, maybe possible to just lower it enough to access the canister fasteners.
Before doing all this , why are you replacing the canister? Are you certain the problem isn’t just one of the rubber lines connecting to the canister is loose, deteriorated, or problematic connection on the other end?

Aftermarket repair manuals have to condense the info to make it fit for all the model years and various options, so not unusual to find instructions that won’t work for your particular car. Having one of those manuals however is much better than not having one. If you want the instructions just for your car, probably have to get a short term subscription to a repair database service. Buick might have such a thing, or All Data, etc. Sometimes a manufacturer’s shop manual will be available in CD ROM format from internet sites, so check there too.

BTW, if you are new to diy’er repair, this is probably not the job to start with. If you try anyway, make sure to follow all the gasoline safety precautions, esp the one about having a big fire extinguisher on hand that you know works.

I remember @gudenteit

He’s posted for quite a few years now

Seems to me he knows a thing or two :smiley:


I bought a new canister to have it ready if i do actually need one, i did get a trouble code on it a while back but it stopped alerting me. And yet I realize that this may be because i had got excess fuel in the tank during a fillup, which since probably got naturally purged out. When i get the fuel ran down in the tank, lower or remove it and get access to the solenoid valves, hoses, etc. to try to find out just what is wrong, if i can fix it, i could send the new canister still in its shipping carton back to Amazon for a refund.

You can no longer overfill a gas tank where it saturates the carbon canister.

The ORVR system has an overfill check valve that prevents that from happening.



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Keep in mind that those Chiltons and Haynes manuals are not only way short on useful information they are also quite frequently wrong with the instructions they do give.

It seems to me they just throw mud at the wall and hope some of it sticks. Some may remember electrical issues I was having with my 1998 Sonoma a while back. The Haynes 1994-2004 manual does not even mention a BCM anywhere in the manual nor is it even shown in the wiring schematics which are said to be “typical”.

A Chiltons I have for 4th gen Camaros states that “normal oil pressure” is 6 PSI at 1800 RPM on the 3.8. That is mind boggling asinine.
And for what it’s worth, even factory manuals have mistakes now and then.

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My Dad put it something like this: " some things are only made to sell, not to work"


The valve that keeps an overfilled tank from saturating the vapor cannister must be a float valve that allows fumes but not liquid past it. And so if i didnt saturate my canister so there was no fuel in there to get eventually purged out naturally, but i still got a trouble code for the canister even though it never came back when i reset it, im wondering if there is in fact something wrong with my canister. New trouble code or not, do they get consumed or otherwise become impotent in a 22 year old car?

The weight of the tank is insignificant, it doesn’t matter if it is metal or plastic. It is the gasoline that is heavy


My 50 year old truck has the original canister, primitive evap system of that era, may not be working 100%. My 30 year old Corolla’s canister is also original, never any problems or canister related diagnostic codes.

The code you mention, while might be referred to as a “canister code” may not be an actual problem with the canister itself; in fact more likely to be one of the valves that route the canister fumes and air to where they are supposed to go. Purge and vent valve failures pretty common reports here on OBD II vehicles. Suggest to post the actual diagnostic code, likely starts with the letter “P”. No experience with your car, just a guess.

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Thanks for info George. Besides obvious broken wires or torn hoses or open circuit on the coil of the vent and purge solenoids, how would i test the conponents? I would say that the purge valve would be normally closed so i could check for leak-by through the valve then. Or if the coil has continuity and no fuse is blown but the plunger is seized, that would mean the valve doesnt open when voltage is applied to the solenoid coil. I’d say then that i would need a new purge valve. And im thinking that the vent valve would be normally closed also, and the same type of testing done to it?

The vent valve is normally open.

It only closes when the EVAP system tests for leaks.



Could a vent valve malfunctioning cause any e gine performance or poor gas mileage problems? And last night my Daughter & i drove to Sandusky Ohio from Toledo Ohio with my boat in tow and at the end of the trip the car kept stalling out at idle & running erratically at times. I also wondered if that could be a bad crankshaft position sensor, if that could be an intermittent problem.

I dunno. I’ve had two crank sensor problems. The one just stalled me with no warning. The other had a crack and caused a chugged on a hard acceleration. Then it finally broke and stalled me. Seems like more a fuel delivery issue, lean or rich, maybe due to sensors or over heating ignition components. But what do I know?