I just picked up my MD 300sd (w126) 3 weeks ago. It is in great shape fwiw I paid 1050.

I was planning a Diesel purge so I let the Fuel tank run low on fuel, but I ran out of fuel instead. I ran out as I was pulling into the parking lot. I purchased the purge and put it into the fuel tank with a gallon of diesel that I was carrying for this purpose.

Later that night I went out to the store and ran out of fuel. I called Mercedes Roadside Asst and they had fuel brought to me. The car would not start. We ended up towing it to my house which the tow truck driver did at no cost to me.

I suspected I might have a clogged tank screen. My Mech suggested blowing air thru the fuel line to unclog the screen. I dont have a compressor yet so I used a manual oil pump to pump fresh diesel thru the line back to the tank. I then pumped a gallon out of the tank and repeated the process agian and again and again.

My primer pump seems to be malfunctioning so I used the oil pump to prime the fuel system. I replaced the primary and secondary fuel filters and then blew the bubbles out of the filter but inserting the hose from the oil pump into the fuel line and then pumping fuel into the line. This cleared the bubbles/air out of the filter put would not prime the rest of the fuel system. I made a small temp. fuel tank and placed it in the eng. compartment with no success. Still won't start.

I've charged the battery several times. I have a very good battery charger. But cannot get the engine to start. It cranks slow after just a few tries. It just turned cold in Syracuse NY, about 40 to 50F.

A buddy of mine says that I could pull start this car by towing it to 20 mph and dropping it from N to Second. He says it is the recommend procedure in the SD300 manual. Can anyone tell me if this will work w/o damaging the car.

I would just take it to a diesel mech but I broke my foot the day after I got the car and money is kinda tight. If I can get the car started I could get to work and then get some winterization done.

BTW. The car ran it's best ever with the diesel purge. Much more power. She was smoking a lil bit at a.m. startups and after idling a bit at traffic stops. She also has some vac. issuues that need to be addressed.


Any help would be appreciated.
dePlane.

How long did you crank the engine? You probably still have air in the injector lines and spin-on filter. It may take up to a minute of total cranking time to purge all the air out. Of course give the starter a break every now and then.

__________________
2004 VW Jetta TDI (manual)

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

I have cranked it many many times. I crank it for 20 seconds and then give it a 1 minute rest (give or take) between cranks. I bleed the spin on filter of air but nothing..... Before I ran out of fuel she started up easily each time.

thanks for the reply

Did the glow plug light on the dash come on like normal? I would start by checking if you have power to the glow plugs? A diesel will start wittout the glow plugs after cranking for a long time in warm weather but not cold.
If there is no power to the glow plugs there is a fuse for the glow plugs that may be blown and is simple to replace. Next try to check the individual glow plugs. They each should draw some current. With a jumper wire connect the battery posative to each glow plug electrical connection. Do you get a spark when you connect? If not you may have bad glow plugs.
If the glow plug system checks out you may have to replace the primer pump as I have seen some of them leak air into the system and cause problems.
John

I was going to test the glow plugs this evening. The GP light does come on but never goes out. the buzzer buzzes for 7 seconds and then I wait an additional 5 seconds b4 cranking. My Mech friend in VA gave me the process for checking the glow plugs last night on the telephone. I will test them after the youngins get home from school. thanks for the reply.

Can you all tell me what the benefits of the Mercedes Roadside Assistance is? I hear all the Mercedes come with lifetime roadside assistance? I have AAA in California and have called on them a twice to get me out of tight spots. Once when car overheated and once when the fuel return line came off and spilled fuel all over the place and emptied my small diesel tank.

[quote=dePlane;1667725]
I called Mercedes Roadside Asst and they had fuel brought to me. The car would not start. We ended up towing it to my house which the tow truck driver did at no cost to me.

__________________
1987 Mercedes 300sdl, 280k mi (daily driver)
1982 Mercedes 300sd, 205k (occupying driveway)
1985 Mercedes 300d, CA, 148+ mi.
1986 Chevrolet suburban, 50k? or 150k? mi, diesel
1998 BMW 740il, 120k mi (for sale)
1999 Honda CBR900RR, 42k
1997 Jeep Wrangler Sport, 103k miles (sold)

I don't think it has anything to do with the glow plugs. It sounds like you did not purge the system correctly. Make sure there is enough fuel in the tank and your lines are tight at the primary. Unscrew the primer pump and start pumping away. It may not sound or feel like it is working but keep pumping. You should have your secondary filter slightly loose at this point. Keep pumping and when fuel starts to leak from the secondary, tighten it up. It may still take a crank or two to start.

BTW, you can do a purge w/o draining your tank.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

Some engines require you to crack the lines to the injectors to purge the air.........otherwise they won't force it through the injectors.

Keep your foot on the floor and look for fuel dripping from the cracked lines. If you see it, then tighten them up and start the engine.

For the lifetime of the car, regardless of who owns it, Mercedes will bring you a few gallons of fuel, give you a jump start (or sell you a battery) and change a flat tire (with your tire and tools), free until the call and I think those services are complimentary as well. They will also arrange to be towed... but I am surprised they took it to his house. I thought I understood that they would only tow it to a MB dealership where they could get you for astronomical labor and parts (Which beats being stuck on the road unless you're like me, a college student who couldn't afford to pay them even if they did work on it and hand me a bill...).

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~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

I was in a spot. So I called 411 and got the number to roadside assist. I knew it was only good for fuel and flat tires and such but hey I only (thought) needed fuel. The Tow truck driver was a real good sport. I knew he wasn't supposed to tow me for free and was real surprised when he offered to help. He said he had nothing better to do: it was 3 a.m. I tipped him good but wish I had more to give him as he saved me a bundle. Not to mention logistical headaches. The big advantage to MB roadside assist btw is that it is FREE for the life of the car.

Thanks for all your replies, y'all are great.

I know this now. The hard part about trial and error is the errors. I'll keep on learning. I luv my new/old MB even if it is a doorstop at the moment.

I've heard this as well. My Mech. who btw sold me the car lives in Hampton Roads VA. (fwiw - I live in Syracuse NY) said he doesn't think I need to go to the trouble.

If pulling the car doesn't get her going then I give up. I'll have to find a local MB Mech and let him bail me out of this one. I have a good one in mind, hope he isn't too busy.

Good Day!

Don't give up! Bleed the fuel system at the injectors. I have done this many times on other engines and it always works if you keep at it. (Unless there's something else wrong with the engine, of course)

Crack the lines at the injectors, crank for about 10-20 seconds at a time and let the starter cool off in between. If it takes more than one or two cranking tries to get fuel at the injectors, you'll want to use a charger or jumper cables to keep the battery going. Once you get fuel at an injector, tighten the line back up and keep going with the other injectors until you have fuel to at least three. I used to do this all the time and found that a V-8 will usually start once you have fuel to four injectors, so a five-cylinder should take about three.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

I was going to crack the hardlines but my Mech said I shouldn't need to.

but just in case do u know of a link that describes the process.

Do I just open each line one at a time or all five at once?

As soon as I get back to work I'm gonna get a repair manual and some new tools and some winter maintenance. Timing and bad luck have me exasperated. But it is only a matter of time b4 me and the car are back up to speed.

This is my first diesel auto. I've been a shade tree mech for years, but at times I get in over my head. From what I've read online, I'm gonna enjoy working on and maintaining this car. I dragged home 2 300d's before I found the 300sd. The 300's proved to be unroadworthy, the poor souls had been mistreated and they went to the boneyard because I was unable to store them.

Thanks again everyone for your help. I look forward to the day I can assist some of u and others.

Okay I won't give up. Until I bleed the injectors that is.

Tomorrow, I'll pull her a bit. If that doesn't work I'll bleed the injectors. My thinking was that this is where I was headed anyway. I was surprised that my Mech. stopped me in my tracks.

Do I open the lines one at a time or all at once? Any direction would be most helpful.