petrol splashes out of fuel tank

[kelly moist]

Persistent problem with my fuel tank - every time when refueling, petrol splashes out onto the ground, forced out by accumulated air (?). The only way I can fill up these days is by not pressing the release handle on the petrol hose full way down - I press it only a little bit, the amount of petrol is reduced and I spent three times longer filling the car. Please help!

 

[Alpo of the Dogs]

I'm having the same problem with my '88 260E and the problem lies in the fuel tank ventillation. There may be a clog in the line that goes to the charcoal cannister causing a build up in octane vapour pressure, which triggers the fuel pump nozzle's shut off mechanism.

I've read in other posts that replacing the charoal/carbon cannister will do the trick, or inverting the fuel pump nozzle, may be even finding the fuel tank vent line and spraying it with compressed air to dislodge whatever clog may be inside.

Another post that I have read suggests running the engine with the fuel cap off so that you can vent some of the vapour pressure with in the tank. I haven't tried these yet as I am currently 220 miles away from my car, but I'll update my thread as soon as I'm done.

HTH!

 

[kth286]

kelly

If you have the charcoal filter system on your car, then the filter should be changed as a service item (every 72,000 miles on mine) otherwise it can get clogged. There have been instances of the fuel tank collapsing if not changed, with all the expense that entails.

The filter is normally inside the NSF wheel arch behind the liner and hence is a bit long winded to change, that's why it often does not get done.

It's not difficult, but do make a note of the pipe connections and DO NOT mix them up on reconnection.

Regards

 

[kelly moist]

Thank you - I kind of suspected the fuel filter could be the culprit - will have to change it despite rusty connections either side. Thank you all for your help!

 

[tom7035]

Hi Kelly, David is talking about the charcoal filter, not the fuel filter, which is quite different.
Cheers, Tom.

 

[kelly moist]

Thank you Tom - My car is an old 280TE - do they have these charcoal filters on them ? - I thought they were a relatively new technological innovation. But then again I am blissfully ignorant about these things. And if they do have them - is changing them a DIY job? Will I need to get my baby on a ramp? Thanks in advance.

 

[kth286]

kelly moist

If you have the charcoal filter (which is likely) you will need to jack car up, near side, and remove front wheel to gain access to inner wing liner to remove the filter.

To find out if you have the filter you could visit a Merc specialist and ask him to look in your engine compartment for the solenoid valve on the NS inner wing which the vacuum pipes from the inner wheel compartment connect to.

Do this before you start doing any work on the car.

Regards

 

[kelly moist]

Thank you for your help! Much appreciated!

 

[tom7035]

Kelly, just for info. - the fuel filter takes out any 'bits' from the LIQUID petrol from the fuel tank before it reaches the engine fuel system to prevent blockages occurring, whereas the charcoal filter takes out the harmful fuel VAPOURS from the tank before they reach the atmosphere (it's a 'green' thing).
So now you have something else interesting to talk to your pals about next coffee morning!