1980 300sd not starting - PeachParts Mercedes-Benz Forum

dieslpwr · #1 10-05-2004, 04:47 AM

Hello, new to the mercedes family and to the sight but eager to fix and drive my newly acquired 1980 300sd W116. I have searched this and a few other sights to try to understand my issues and here they are: preheated and cycled the plugs for about 2 days forgot and left the key on; transmission will not allow the car to shift until you let off the gas (diesel pedal) and ease back into it; and of course the heat and ac. The car is a 1980 300sd 225k+ odo died, 3rd owner Chassis #12 018523, china blue?(navy blue) The car ran fine before the key incident. The car will turn the engine it just will not fire injectors? Previous owner thought the trans issue maybe vacuum but from what I have read it may be due for a rebuild. I do need heat because Indiana can get quite chilly. I love the way the car looks and drives and my 2 year old daughter just loves to play in it. Sorry for being so long winded and thanks for giving me the opportunity to post.

Rick Miley · #2 10-05-2004, 09:34 AM

Actually, I wish you were a little more long winded and a little more clear. With three problems jumbled into one post, it's hard to tell what you're talking about.

1. It seems as though you left the key on and after that the engine won't start. Charge the battery - these things will never start without a good strong battery. You may want to test the condition of the glow plugs. Testing methods have been posted here dozens of times, so they shouldn't be hard to find.

2. Mercedes transmissions of that era are adjustable. There is either a control rod or a cable that runs from the accelerator linkage to the transmission that adjusts the engine speed at which shifts occur. There's lots of info here on that as well, if you search for "transmission adjustment."

3. Your car has something called an ACC (automatic climate control) servo. It is a plastic box in the engine bay (passenger's side) that has electrical, vacuum, and coolant lines running to it. These servos are a well known point of failure for the system. If you decide to replace it, seek out an aluminum bodied replacement part that will better stand up to the heat. Sources have been posted here before if you search for "ACC servo."

dieslpwr · #3 10-05-2004, 11:48 AM

Thanks Rick for pointing me in the right direction. When I do try to start the car I use a 12v. battery charger with a 100amp boost to help the battery along. I also plug the car in to try to help, don't know if this does though? The reason I ask is the mechanic the car will be going to is not that familiar with Mercedes but I trust him. As I am willing to try do some of these myself but I am not the most mechanically efficient so to speak.

Rick Miley · #4 10-05-2004, 11:54 AM

Almost anything that cause one of these not to start is covered here.

dieslpwr · #5 10-05-2004, 12:37 PM

Thanks again Rick. Did the acc servo search now I know what to look for and where. This may be a redundant question but I could not find the answer what is the # of my trans. I printed off the 123/126 trans adjustment directions, it sounds like the other posts I have read that deal with the same year and model as mine.(722???) I figure if I have all the info I can point the shop in the right direction and save myself some unnecessary expenses and time.

Old300D · #6 10-05-2004, 12:50 PM

Quote:

Originally Posted by dieslpwr

Thanks again Rick. Did the acc servo search now I know what to look for and where. This may be a redundant question but I could not find the answer what is the # of my trans. I printed off the 123/126 trans adjustment directions, it sounds like the other posts I have read that deal with the same year and model as mine.(722???) I figure if I have all the info I can point the shop in the right direction and save myself some unnecessary expenses and time.

The transmission number is easy to find. Look at the side edge of the transmission casting where the transmission pan bolts up, after wiping it down with a rag. The number is stamped there, I can't remember which side.

WANT '71 280SEL · #7 10-05-2004, 01:53 PM

First of all, where are you at in Indiana? To adjust the bowden cable on a 116, it is different than the 123 and 126 chasis. It is instead a solid rod with an 8mm nut to adjust it. I've never adjusted mine, though I think it may need it. It comes up from the transmission and attaches to the rest of the throttle linkage. Also, when cranking, is the car puffing any smoke at all? If not, it obviously isn't getting fuel, which I guess is just about the one thing to keep these from running. May also want to look into a valve adjustment, and make sure that the timing chain hasn't broken.
Thanks
David

dieslpwr · #8 10-05-2004, 03:55 PM

Thanks for the trans. info will be under there tommorrow. 71 280sel I am from Kokomo, not the tropical one, just southwest of you. She smokes ahh the smell of diesel; when I attempt to fire but she just will not fire. From what I can tell there is nothing visually amiss about the outer workings of the car. All belts and hoses look fine all attached and not cracked. The timing chain I think I know what I am looking for, looked fine.

WANT '71 280SEL · #9 10-05-2004, 10:57 PM

Have you adjusted the valves? How about cracking the lines at each injector separately to verify fuel? If you have fuel to the engine, and the timing isn't way out, then it will run, not always very well, but it should run. You're sure the starter is spinning enough and that the glow plugs are working correctly? You said you plugged it in, your talking about the block heater, right? Or were you speaking about charging the battery? If I can help anymore let me know. For curiosity's sake, does the car have any rust like all the other older cars around here? I also know of a good person to email in Evansville if you should need any used parts.
Thanks
David

dieslpwr · #10 10-06-2004, 10:35 AM

71 280 sel No i have yet to do those things, the bad thing is I never really worked on cars, I have changed oil in my past wrangler but that is about the extent of it. Yes I have the block htr plugged in along with a 100amp battery charger to help the battery along, when trying to start. My goal is to get enough info to help the mechanic along with the repairs, from what I have been told and read I can do some of these things with the proper tools. The no-how is not there but the willingness to learn is. As far is rust the car is in fairly decent shape some small rust bubbles but no holes the paint on the roof is faded bad-oxidized to the point of no return but I buffed the body out and it looks alot better. Window seals are shot as is the back seat but foam will fix that. Previous owners let the car sit out. Thanks for the Evansville reference I may need that in the near future. Have you ever heard of a shop in Zionsville-Vaughn Motorwerks? Think I can shot some ether in the air intake?