Fuel tank issue

[J.J.]

My '85 MB 300TD is noted in the owner's manual to have a 18.5 gal fuel tank.

The car gets about ~325 miles to the tank when driven until running out of fuel.

When the car is filled up I can get ~15 gallons in the tank.

Where is the mystery 3 or 4 gallons at?

JJ

[phantoms]

I drained my tank yesterday while the needle was sitting almost on R. Drained about 10 gals total out of it.

[Gilly]

JJ: Is that a 300TD as in a "wagon", or is it a sedan body?

Gilly

[J.J.]

Gilly - Its a wagon.

JJ

[pawoSD]

I'd think you could make it a lot farther than 325 before it runs out


With mine filled to the brim I know it will go about 514.4 miles on the freeway around 75mph on one tankful.....


I know this because when we first got the car we didn't realize the capacity or the fact that the sender didn't work.....so we ran out of fuel along side the road about 80 miles from home in southern michigan. We had made it all the way from Harrisburg, PA. State trooper was real helpful in getting us on our way again, they are nice guys! He said "smells like a submarine went down...." when we were fueling.

[J.J.]

pawoSD - Exactly. I should be getting plenty more miles to the tank. The MPG is fine. Its just the tank only holds ~15 gallons.

JJ

[Gilly]

I agree with the owners manual, my sources say 70 liter capacity=18.5 gallons, the sedan is 80 liters, so a little over 21 gallon tank. Your wagon tank is under the rear floor, possibly it is bent/caved in? Or with either a wagon or sedan the vent system may have been plugged at some point and collapsed the tank, seen it happen once! My first thought would be a fault with the gauge system, you might try carrying some extra fuel along and actually try running it out of fuel to see how many miles it actually goes.
If you seem to be running out prematurely you may have a fuel bacteria growth blocking the intake screen at low fuel levels.

Gilly

[J.J.]

Gilly - I ran it dry twice. Its was the same ~325 miles per tank each time. I'll check to see if the tank is collapsed.

Where is the intake screen located?

Thanks

JJ

[Gilly]

Inside the tank. If it's like a sedan (can't remember) there is a rather large hex shape surrounding where the fuel supply line exits the tank, this can be screwed out (preferably with an empty tank ) to inspect the screen.
Yeah, first just look under there to see if maybe there is impact damage (car backed into a rock or parking "dog" and dented the tank).

Gilly

[aklim]

I fill up my tank by inserting the hose and depressing the lever till it clicks off. After that, if I play with it and keep fueling it SLOWLY till I can see diesel fuel at the mouth of the filler tube, I can get about 3 gal more. The fuel does foam quite a bit. When I run it to empty mark and fill it up I get 19.5 gal or so. If I play with it a little more I get 22 or so iin. Supposedly I have a 21 and some change gal tank.

[P.E.Haiges]

I know my '80 300SD holds 25 gallons. I have put that much in it more than once. I also got 750 miles on a full tank which is 30MPG using 25 gallons of fuel.

I know the manual says 22 gallons but I have proved that incorrect.

I agree that the fuel strainer may be partially plugged to reduce the amount of fuel that will come out of the fuel tank. It happened to me.

P E H

[aklim]

Originally Posted by P.E.Haiges

I know my '80 300SD holds 25 gallons. I have put that much in it more than once. I also got 750 miles on a full tank which is 30MPG using 25 gallons of fuel.

I know the manual says 22 gallons but I have proved that incorrect.

I agree that the fuel strainer may be partially plugged to reduce the amount of fuel that will come out of the fuel tank. It happened to me.

P E H

My manual says that it is about 21+ gal and 3+ gal for reserve. Maybe that is what you are hitting?