My 1990 2.5 Turbo has a pretty bad fuel leak. I could see fuel dripping off the oil pan. I cleaned the area around all the hoses, and noticed that one was spongy on the end. Upon closer inspection, none of the hoses was up to standards. So I replaced the three 5/16" hoses that run up under the Window washer canister (I had to remove it to get to them comfortably). Then I started the car and there were no drips at all.

I did a short victory dance. Short because my back was sore from all the bending over. It was not easy to unscrew the hoseclamps because of the angle I had to turn them at.

Then I drove down to the station (about 10 blocks) to put in about $15 of petro Diesel. On the way, it seemed to have lost a lot of power and it seemed that I was running out of fuel, but the gauge was a notch above empty and the light was not on.

I barely made it to the station. I put in the fuel, and looked under the engine and saw no drips. It ran good and strong all the way home, but when I checked under the engine again, it was leaking AGAIN.

I have been using biodiesel for about a year. The hoses I replaced were gooey ad soft and clearly needed replacing, but the leak was not coming from any of the six connections on the three hoses I replaced, not from the larger hose that goes up to the large filter canister.

The return hoses are fairly new and not leaking. The two longer hoses I replaced connected to metal fittings. Is there another rubber hose between the engine compartment and the tank? Could this be a leaky O-ring? If so, what size do I need?

I suppose I will have to jack the car up and look very carefully, but if any of you can tell me where to look, I will be most grateful.

__________________
Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)

I would check the delivery valve area on the injector pump. There are small rubber o rings that can leak when the engine is running. If it is a small leak, and the engine is run for a short period of time, the fuel will usually just evaporate while the engine is still hot. If it is a bigger leak, and the engine is run for a longer period, the fuel may work its way toward the back of the block, and drip down. In my case, after going on a trip, the leak at the injector pump would not be too evident, but I would find pooling of diesel fuel in the bellypan. What I would suggest, is to wipe down the delivery valve area, start the engine, and keep it running for about 5 minutes to see if any sign of leakage can be noticed. Good luck.

__________________
96 E300d

Diesel evaporates? I was unaware of this... maybe off the exhaust manifold...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Well, I finally located the leak. After I replaced the o-rings and metal washers on the diesel injector, I finally noticed the leak: the return line on the No 5 injector was loose. I have no idea why I did not spot this sooner. Perhaps somehow I loosened it while I was removing the window washer bottle to get to the three hoses I replaced.

I guess I assumed that the return lines were OK because they were changed less than a year ago. The leak was a split in the end of the hose, that was squirting the fuel downward, where I could not see it.

If I were a professional mechanic, I expect I would be either reprimanded or kidded about this, possibly both. I feel a bit like a fool for not seeing this immediately, but reasonably clever because I did find it after all.

Later, I'll get Viton lines from McMaster and replace all the rubber ones.

Thanks to everyone who left a note. It was appreciated.

__________________
Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)

Diesel often blows rearward, wicks up, flows down and is very deceptive disguising where it is coming form.

A can of carb or break cleaner creating a clean work area combined with another days driving before looking again USUALLY helps finding the culprit.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

if the engine block is up to temperature, it can dissapear in a hurry if the valve seals are not leaking too bad.

MATERIAL SAFETY DATA SHEET
Diesel Fuel (All Types)
MSDS No. 9909
Revision Date: 10/18/2006
Page 5 of 7
.
9.
PHYSICAL and CHEMICAL PROPERTIES
APPEARANCE Clear, straw-yellow liquid. Dyed fuel oil will be red or reddish-colored.
ODOR Mild, petroleum distillate odor
BASIC PHYSICAL PROPERTIESBOILING RANGE:320 to 690 oF (160 to 366C)
VAPOR PRESSURE: 0.009 psia @ 70oF (21oC)
VAPOR DENSITY (air = 1): > 1.0
SPECIFIC GRAVITY (H2O = 1): 0.83 to 0.88 @ 60oF (16oC)
PERCENT VOLATILES: 100 %
EVAPORATION RATE: Slow; varies with conditions

__________________
96 E300d