I didn't think I was a stupid blonde, but may be I am after all. I have
a 4 month old Merc. 240 Formatic. I have trouble with the fuel cap.
After using it a few times, I can't screw it back in nor can several men
I asked. Took it back twice already, and then got a lesson on how to
screw it off and in again. How come it's so difficult? It seems that
after getting gas a few times, it won't close anymore. The guy at the
dealership told me there was a spring in there, and if not opened or
closed properly, the spring or whatever jumps over somethin like a
notch. He's had 8 people come to him with same problem (I'm sure they
weren't all blonde females either). Has anyone an explanation and a
foolproof method for handling this?
You could try to really p*ss off the dealership as follows.
Buy a plastic 'fits anything' spare filler cap. Each time the Merc cap won't
go back on, fit the plastic. cap and take the car back to the dealer for a
warranty job. If they get stroppy, mention that a correctly fitted fuel
filler cap is a health and safety issue.
I'm glad you replied. I thought maybe people think I was joking. I wonder if a
plastic cap would even fit. I had a Toyota Camry before and didn't have the same
type of fuel cap. It just had a simple "screw it to the right or left" system
that clicked right in. The Mercedes one has the notches, and I have a feeling an
ordinary cap wouldn't fit. Hmm
The Mercedes one has the notches, and I have a feeling an ordinary cap
wouldn't fit. Hmm
All the parts stores like NAPA, etc will have a cap that fits your car. And
they are not expensive.
if the cap does not fit the car will not pass a smog inspection covered
50,000 miles <100,000 Calf>
i am sure it must be fixed at no charge if i am not mistaken.
i hung GM on that.
the case, minus a few cans!
NAPA is a auto parts chain in the USA....find a chain in Canada or even a
good local parts place and you should be able to get a gas cap. Another
place to get MB gas caps is www.performanceproducts.com
I bought a factory specs cap with the MB logo on it for $6 about a month.
If the fuel cap for your MBZ is anything like that for my girlfriend's
2000 SLK 230, then you have my sympathy.
After tanking up, I "screwed" on the gas cap of her car without paying
much attention to what I was doing (what's there to worry about when
screwing a gas cap on?).
I heard a click.
The cap seemed "on" but it seemed to be at a slightly cockeyed angle. I
backed it out and discovered thereafter that I couldn't get it back on.
After many failed attempts, I approached someone who had just pulled up to
another pump to get some gas and asked her if I could look at her gas
After giving me a very strange look, she let me take a look and I
discovered that gas caps aren't what they used to be (i.e. I had a good
Her car was NOT a MBZ but it had an identical cap. So the problem that I
had probably has happened to others whether they were MBZ owners or not. I
suspect your experience was/is another example of this problem.
If you look at the backside of an old, traditional gas cap, you'll see
that there are two "ears" inside the cap. When you place the cap on the
end of the pipe coming from the gas tank, the ears pass through two
openings in the rim of the pipe and, when you rotate the cap, secure the
cap to the pipe.
In the new gas caps, there is a nylon ring behind these ears that has it's
own pair of "ears". The nylon ring can rotate. When you take the gas cap
off, and look at it's backside, you'll see that the metal "ears" are
sitting on the "ears" of the nylon ring (when things go as they are
To accommodate this arrangement, the two openings at the top of the fuel
tube that I mentioned above are larger than that in the old fuel tubes. As
a result, I would not be surprised if an old, standard fuel cap wouldn't
work on these new gas tanks (but then I haven't tried to put one on so I
may be wrong).
The reason I couldn't get the cap back on was due to the fact that the
metal "ears" were not sitting on the nylon "ears". They were sitting in a
pair of detentes in the nylon ring 90 degrees from where they were
supposed to be. Apparently, I hadn't positioned the gas cap correctly
against the end of the fuel tube before spinning the cap to the closed
position. The result was that the openings in the rim of the fuel tube
engaged the nylon ring somehow and rotated it relative to the metal
When you normally put the gas cap back on, you position the cap so that
the nylon "ears" sit IN the two openings at the end the fuel tube. You
then push the cap firmly against the mouth of the tube causing the two
metal "ears" to move deeper into the fuel tube past it's metal rim. When
you rotate the cap, the metal ears will then rotate and secure the cap to
the fuel tank just as they have since God-knows-when. The nylon "ears"
just stay in place in the openings at the end of the fuel tube.
Here's the fix:
Take two metal blades and, using the lip of the fuel cap as a fulcrum,
lift the two metal "ears" up (held in their normal position by "the spring
in there") high enough so that you can then rotate the nylon ring to where
the nylon "ears" are underneath the metal ones. At that point, you can
then release the metal "ears".
I happened to have had a pair of small, metal spoons in my daypack
(souvenirs from a meal I had on an SAS flight ages ago). I positioned the
two spoons so that the end of their handles were underneath the ends of
the metal "ears". Pressing the other ends of the spoons down lifted the
"ears" high enough so that I could rotate the nylon ring into the correct
position (a test of your dexterity if you lack a helping hand).
Hope this has been of some help.
P.S. Maybe you ought to get a spare cap for a backup if this is a
recurring problem. When the first one fails to work, use the second one
and reset the first one when you get home.
So do you suppose that Ole Jerkin Shrimp over there in Germany will enjoy a
little bit better retirement becaue you have to poke around in the gas tank cap
and fix it? Boy, what a brand!!!!! $40K to $120K and you have to buy a spare
gas tank cap !!!!!! SHEESH!!!! And I used to think it was realllllly bad to
have to pay extra for the CD player that comes standard in the Dodge Neon!!!!!
mcbrue corkingly under the bridge in the trailer down by the river
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