New guy, 1993 300D first diesel - PeachParts Mercedes-Benz Forum

Drago · #1 03-08-2014, 04:02 PM

First Mercedes, 1993 300D. I have two GMC trucks 6.5L diesels so I'm not totally unfamiliar with oil burners. So before I start throwing parts and time at my 300D let me describe the problem(s) it has 173K on it. Idle is rough but smooths out with a little throttle. When I take off at a light it hesitates a lot and belches black smoke and then starts to roll and accelerates. I can hear the turbine spin up. This vehicle sat around awhile so I suspect some gunk in the fuel. I plan on changing the two fuel filters.

Is there a special procedure to change the filters?

Is there anything else I should look at.

I've only had this vehicle 6 hours so any advice would be appreciated

macdoe · #2 03-08-2014, 04:34 PM

There is a fuel tank strainer, that can get blocked from algae, presumably from aged diesel....type in" fuel tank strainer" in the search part. Same with the fuel filters. That should give you a place to start? How long did it sit exactly? How hard was it to get started?

Welcome.

P.S...your parts would probably be less than 50 bucks or even cheaper, if you could just wash the existing in tank fuel strainer filter... clean and re-install...that strainer part is something like $33...and some people just clean the original and re-use if they are still good. There is a large o-ring for this part to seal, upon re-install, you may need? Not sure if it is included with the new tank strainer or needs to be purchased separate? There looks to be 2 fuel filters under the hood of that one. 10 bucks for the spin-on filter that looks like an oil filter and 3 bucks for the small clear plastic pre-filter.

shertex · #3 03-08-2014, 04:39 PM

Try to get the spin on filter as filled with fuel (or ATF) as possible before starting....it will make cranking a lot easier.

Mxfrank · #4 03-08-2014, 04:49 PM

The spin on doesn't spin on. It unbolts from the top. A little fuel or oil on the gasket will help it seal. As mentioned, fill it with Diesel or oil before retstarting. Your car doesn't have a priming pump, it's a pain to get started after a filter change. What you have to do is crank for 15 seconds, let it rest, then crank for 15. People will tell you to crack the lines open, this is nonsense it doesn't help. Just crank and be patient, it will start. The most important thing is to let the starter rest for awhile between cranks, otherwise you will burn out the starter.

Lots of reasons for rough idle, but start with the filters.

Drago · #5 03-08-2014, 05:30 PM

I don't know how long it was sitting but it accumulated some leaf litter under the hood. the fuel cap was a little rusty and the tank was on an eighth. I test drove it, bought it and put ten gallons in with some Diesel Kleen Silver. I've been here before with my truck, the fuel "sock" was clogged. had to use a five gallon bucket in the bed with the fuel lines stuck it to get home. This looks like it might be easier to handle, the truck you have to drop the tank.

Drago · #6 03-08-2014, 05:35 PM

Do they make an after market plastic fuel tank? I use them in my trucks because I run B100 most of the time

macdoe · #7 03-08-2014, 05:49 PM

At a certain year, they went from plastic to metal in the w123 chassis, or was that the other way around? But you have a w124??? So someone else might know more about that one...I only have w123 and w126 cars.

shertex · #8 03-08-2014, 05:58 PM

You can crank longer than 15 seconds with your car....30 seconds is perfectly safe from everything I've read. IF the filter is filled or almost filled with fuel, you should not need repeated cranking cycles. It will catch then die; when you crank after that it will catch, sputter a bit, then be fine.

BTW the best way to get the filter FULL is to put it in place, wedge something under it to keep it in place, fill with diesel or ATF to the very top, screw in the bolt, then remove the wedge. Other approaches can be messy.

Drago · #9 03-08-2014, 06:13 PM

Quote:

Originally Posted by macdoe

At a certain year, they went from plastic to metal in the w123 chassis, or was that the other way around? But you have a w124??? So someone else might know more about that one...I only have w123 and w126 cars.

Idunno how can you tell?

jake12tech · #10 03-08-2014, 06:39 PM

Quote:

Originally Posted by Drago

Idunno how can you tell?

W124s got plastic fuel tanks in '86. Diesel & Gas.

oldiesel · #11 03-08-2014, 06:55 PM

both my 87 wagon and my just sold 91 sedan had/have metal fuel tanks.No doubt in my mind as i had the tank out of the 91 to clean it before running 100% home brew bio D .The wagon, i removed the sender to clean it and the strainer.

macdoe · #12 03-08-2014, 06:57 PM

Would a magnet stick? Or is that an unsafe technique? Maybe they are coated with something?

whunter · #13 03-08-2014, 07:19 PM

Quote:

Originally Posted by Drago

First Mercedes, 1993 300D. I have two GMC trucks 6.5L diesels so I'm not totally unfamiliar with oil burners. So before I start throwing parts and time at my 300D let me describe the problem(s) it has 173K on it. Idle is rough but smooths out with a little throttle. When I take off at a light it hesitates a lot and belches black smoke and then starts to roll and accelerates. I can hear the turbine spin up. This vehicle sat around awhile so I suspect some gunk in the fuel. I plan on changing the two fuel filters.

Is there a special procedure to change the filters?

Is there anything else I should look at.

I've only had this vehicle 6 hours so any advice would be appreciated

whunter · #14 03-08-2014, 07:38 PM

This should be a turbo engine, and you may also have this common issue.

http://www.peachparts.com/shopforum/diesel-discussion/328792-car-not-accelerating-properly-cutting-out.html

.

compress ignite · #15 03-08-2014, 11:27 PM

[Unless someone has replaced it,previously]

1.Get some Startron Diesel Fuel Enzymatic treatment 8 oz. and add to a 1/2 full or so Tank of DieselFuel.That'll take care of any Fungus Infection in the Fuel system without clogging any filters.
2. Start Reading this post:
http://www.peachparts.com/shopforum/diesel-discussion/212097-wastegate-actuator-swap-om602-962-a.html
3.Visit:
http://www.w124performance.com