Help! its saturday and the shop isnt open until monday! I refueled my car on wednesday night and immediatly noticed the diesel smell in my car. I checked to make sure i closed the tank and indeed, i did.

for the past few days the smell remains and my 1984 300D is losing fuel fast. its hard to tell from the pictures but the there is diesel leaking from the bottom nipple hole, and u might be able to see there is diesel on the rubber insulation around the tank cover.

let me show u:

http://mywebpages.comcast.net/eplack/upload/Leaky%20Deisel%20001%20(Small).jpg
this is three days worth of spillage, when i wasnt at work

http://mywebpages.comcast.net/eplack/upload/Leaky%20Deisel%20002%20(Small).jpg
more (i park in different spots obviously)

http://mywebpages.comcast.net/eplack/upload/Leaky%20Deisel%20003%20(Small).jpg
its hard to tell but that entire area is coated with a slick of fuel, and the rubber is moist

http://mywebpages.comcast.net/eplack/upload/Leaky%20Deisel%20005%20(Small).jpg
there's some outlet hole, coated in fuel

http://mywebpages.comcast.net/eplack/upload/Leaky%20Deisel%20006%20(Small).jpg
this concerns me that there is also fuel here, at the base of the rear passenger wheel well. shouldnt the leaking diesel go out the hole above?

the cap is on tight, so i think the leak is elsewhere... What gives?

eplack,

The hole in the side of the body you dubbed "some outlet hole, .." is the fuel tank vent line. You may have a wetness there normally, especially if you top off the tank to the point where you can see Diesel fuel liquid at a steady level in the fuel filler neck. I doubt that is the real source of your problem.

You will have to get under the car and look at the bottom of the tank where the fuel lines are connected. I would suspect you have a leaking hose connection or two there. They are a huge mess to change as you WILL spill Diesel on your self. Even if you drain the tank into another container, you are virtually guaranteed to get stinky.

At the age of your car it is normal to have a fuel leakage problems from old, rotting hoses. It is also pretty normal to start changing them as they fail. They start at the tank and go to the injection pump and then there are smaller ones that connect each injector to the next (the one against the firewall in the engine compartment has a "blank" installed to plug it on the side that has no final injector). The hoses connect between the metal fuel lines that run along the body, in general. So the lengths are pretty short, and the connections pretty accessible, even the ones on the tank, once you get down there. Good luck, 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 can't remember for sure, but isn't there a short hose between the filler cap and the tank that can leak?

__________________
1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

In general I have found leakage at the filler cap a consequence of overfilling the tank when the fuel is particularly foamy. A big blob of foam can burp out now and then, causing the filler cap cavity to get a little wet with Diesel fuel. Fuel leaking out the vent line is an indication the previous owner regularly overfilled the tank.

I do that too, but it is not a good practice if you fill it to the point where liquid fuel is visible and then park it. When the fuel leaves the underground tank it is usually around 60*F. During the day it will get warmed to the ambient air temperature, which in the Winter is usually not a problem. In the summer it will cause the fuel to expand significantly, and it will force itself out the vent lines.

This makes the vent line rubber junction fittings get soft and slimy with Diesel fuel, and can lead to vent line leaks or vent line plugging. There is a little tank on the passenger side outer wall of the trunk, behind the wheel well, I believe, that is intended to address the occasional burp of foam, separating the liquid from the vapors and air, and letting the liquid run back to the tank. If you fill it with fuel the fuel has no place to go but out that little fitting.

The fact that the fitting is wet is a good indication the cap and the filler neck are not damaged. The filler neck, I believe, is a solid pipe, but its connection to the body in the little cavity enclosed by the body fuel filler flap is rubber to allow the tank to move independently of that connection to avoid overstressing the filler neck as the car body flexes going over bumps and taking corners, etc.

Hope this helps, and good luck fixing that leak. 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)

eplack

I spent the morning changing out the 3 hoses under the fuel tank of my wifes "79" 240D. The 2 on the left are the vent and return lines and the one on the right is the supply line. When these lines leak it drips right on the axal boots so its a good idea to not let that happen for too long. I ran the fuel well down then siphoned out the rest. You will still have fuel running out so have a old dish pan ready. On the supply line you can cut off the fitting on the tank end of the hose ( cut off the metal crimping the old hose and reuse the rest of the fitting) and slip new hose on, then secure it with a regular hose clamp. Not a bad job but like Jim said "it is messy"

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

wow. thanks a lot folks.

im pretty sure i didnt over fill it cuz i only paid for $20 worth and it cut off at $20, but it seems the expansion idea is probably what happend. the funny thing is, is that it's under half full and still leaking.

Jim, why would there be diesel driping from that rust in the body, vs the vent line hole?, this concerns me b/c im sure the diesel only adds to the corrosion.

just these past few days it hasnt been stopping with the key as well. im used to this problem having driven various diesels for 4 years, but it usually happens to me in the winter, not on the hottest day of the year.

in fact, today it wouldnt even stop when i pushed the stop lever. can't imagine why.

by the way ill probably have the shop look at it. Im more likely to damage something then do any good.

eplack,

The chances are your present problem is one of the hose connections to the bottom of the tank. As the fuel leaks while you drive, it gets sprayed around pretty good so looking at the wetted areas from above will not be very definitive. Until you crawl under there and take a look, you won't know for sure though.

Failing to stop with the key is a vacuum issue, and if you do a search you will find lots of answers. This is a very common problem as vacuum is used to do a number of actuation jobs and after time the tubes and connectors get old and fail, as well as the vacuum actuators themselves.

Good luck, 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)

Most common shutoff problem is actually a bad bit of rubber hose between the main vac line and the plastic tubing -- they get old and hard and leak or break.

You have to push down pretty hard on the shutoff lever on that engine, not like some of the others.

Check the condition of the rubber seal in the filler cap -- if it is bad (if you can see a distinct dent where the lip goes it's bad) and fits loosely, you will splash fuel out on bumps and turns. I have this problem on the 280 SE, and have an aftermarket cap on there at the moment. Quite a bit of fuel will spill out, then drip for a while. Diesel won't evaporate at ambient temps very fast, so it stays around.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

In your trunk, remove the right side plastic trunk liner that lines the entire right inside of the trunk/fender hump. There is a plastic/rubber vent line that is a pressure fit on the backside of the fuel filler pipe. Mine disconnected and allowed fuel to spill out inside the trunk behind the liner, and drained out through the drain hole behind the right rear tire you picture.

Good luck.

J.G.

Did you pull on your fuel cap to make sure you installed it right? It's possible to install the cap with one of its teeth outside of the filler neck. The cap will then act like a flap, opening during turns and spilling fuel. Happened to me once.

__________________
2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Yup...that wasn't my problem. I pulled out the inside trunk liner and actually found the vent hose detached from the filler assembly.


J.G.