Hello Everyone
Here is a laugh for you.
I just got back from filling the fuel tank.
When the fuel cap was twisted; it blasted out of my fingers and hit the fuel pump.
There may be just a little pressure building in my fuel tank.

Oops:
1985 300SD W126

Whunter,

How would that much pressure build up in your fuel tank? Obviously your vent is plugged but what would cause that much pressure?

P E H

happened in the SL once or twice

__________________
Adam Lumsden
(83) 300D
Vice-President of the MBCA International Stars Section

I have gotten no warning signs.
Last fuel fill was three days ago, a slight sucking sound was normal, prior to this incident.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

What was the ambient temperature in your area when this happened?

It happens to me, but only when ambient temperatures are relatively high. i.e.: 85F +.

I therefore suspect that this may be normal.

__________________
'95 E300 Diesel, 264,000 Miles. [Sold it]

Yesterday was 69°F
Last night was 57°F
Today 66°F

The last seven days as a graphic.

Attached Thumbnails

 

whunter,

I think you have a W123. If this happens on one of them, you definitely have a stopped up vent since on that car, the vent is really designed to keep the tank at around atmospheric pressure. About the only thing I can think of is if the weather is hot enough, and if you drive in the city enough, the underhood temps are making the return line fuel hot enough to cause the bulk temperature of the contents of the tank to warm up. Diesel fuel expands quite a bit when it warms up, so this could cause an increase in tank pressure. I have actually had the opposite experience with my Father-in-Law's car. He had his vent line plug and then as the engine ran, it drew a vacuum and stopped the car from running. He went to put fuel in the tank and the cap wouldn't come off. He has hands like some monster though and managed to twist the cap off only to hear a sucking and whooshing noise. The vacuum was bad enough to make the float behave oddly too. The reserve light would come on while the needle showed more than half a tank. But I believe that was in the winter. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I was running Max A/C for an hour prior to fuel stop, engine compartment 90C.
If you are correct, this means my vent is plugged.
Not bad for 18000 miles on a used car that started with 225000 miles.
I will fix that tomorrow, perhaps I will use some of my tools of "mess" destruction. LOL

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

Hopefully it's just a little plug . On my daughter's 240D, the vent line was plugged from one end to the other. This car had sat for some time before I got it for her. Spent a good portion of a day just unclogging it.