300D starting problem - PeachParts Mercedes-Benz Forum

Brewer · #1 03-30-2007, 11:13 PM

Sorry for the 1 billionth starting problem thread, but searched and couldn't find anything that sounds like my problem.

I know my battery is dead, but last week I got it jump started. I haven't driven it to recharge the battery, so I know it's still low. But now I can't even jump start it. (Using a Chevy blazer, has worked in the past)

I can get one or two weak little cranks and then nothing. The glow plug light works and turns off in normal time, so I don't think it's GP related. Since I'm jump starting, the dead battery shouldn't be an issue. And since I get a couple cranks it can't be any fuses or switches.

What's up? Bad starter? I tried the hammer trick, didn't work.

thanks in advance

79300sdtd · #2 03-30-2007, 11:31 PM

if the battery is dear enough you will have to let it charge for a bit before it will start... i have expierenced this many times.

these care take quite a bit of power to turn over fast ehough to start. more than almost any gasser

truckinik · #3 03-30-2007, 11:38 PM

Charge up the battery really good and give her a quick shot of ether, right down the aircleaner intake. Works every time...Forget waiting for the glowplugs, and just turn the key.. Once she's started, just let her run a while.

79300sdtd · #4 03-30-2007, 11:46 PM

Quote:

Originally Posted by truckinik

Cgive her a quick shot of ether

no ether

mespe · #5 03-31-2007, 09:03 AM

No ether. A weak or nearly dead battery CAN bring down the voltage enough to prevent good cranking. Why waste time fooling around when you know the battery is bad? Either buy a charger or a new battery.

Your battery could have a short in a cell causing the charging battery/alternator to be fried.

If you can't afford a battery or charger, take the battery out of the cheby and put it in the benz to test.

Also corrosion in the wiring, bad engine ground, faulty solenoid can cause no start condition.

barry123400 · #6 03-31-2007, 09:23 AM

You probably are not able to pass enough current through your jumper cables to crank the starter properly. Jump starting is just to assist a low battery. It will not replace it totally if fairly low as most cables just do not pass enough amperage along. Why not remove the battery and take it to one of those parts stores that charges and checks it out for free? Then go from there.

Brewer · #7 03-31-2007, 10:51 AM

thanks. I had forgotten the fact that super weak batteries can prevent jump starting. I wouldn't think it would matter if you're jumping with a strong engine but I guess not.

I got a battery charger and when I started it up it read 35%, so it must've been pretty bad.

You're right about the cables, too. They're heavy duty, but they're old and one of the connections lost a few strands of wire.

thanks again.

Brian Carlton · #8 03-31-2007, 11:01 AM

Quote:

Originally Posted by Brewer

You're right about the cables, too. They're heavy duty, but they're old and one of the connections lost a few strands of wire.

With a brand new set of very heavy duty cables, you still can't start a diesel that has a totally dead battery. The reason is that it's nearly impossible to transmit 500 amps through two or three contact points on the clamps. The voltage drops at this point due to resistance and the voltage at the starter is nowhere near 12V during cranking.

truckinik · #9 04-01-2007, 03:08 AM

Once the battery is either charged, or replaced, make sure your fuel system is properly bled out well.

Panzermann · #10 04-02-2007, 11:06 PM

These MB diesel babies require a lot of juice to turn them over. I was once at altitude (a research station at 12,000 ft msl) with a 1984 300TD and the battery was bad and would not start the car. A friend up there had a toyota truck and volunteered to jump me. We connected up the cables, he revved up his engine, I turned my car to pre-glow, he gave me the thumbs up to start her, I turned the key to start and...his truck died! We did eventually restart his truck, but I ended up hill starting the car (yes, you actually can hill or tow start them, although you have to be going about 40 MPH in neutral and then shift into second to crank the engine).

Take home message is to get a nice juicy charged battery if yours is suspected to be no good. You could take the battery to be checked out, and if good, recharge it. A battery charger is a good thing to have anyway. Other suggestion is not to scrimp on the quality of battery cables. Everyone tries to get the cheapoes, figuring that it is just for emergency. Yet it is just in such an emergency that you want really good cables. Large gauge copper cables make a better connection and increase liklihood of a successful jump.

truckinik · #11 04-03-2007, 03:54 PM

Quote:

Originally Posted by Panzermann

These MB diesel babies require a lot of juice to turn them over. I was once at altitude (a research station at 12,000 ft msl) with a 1984 300TD and the battery was bad and would not start the car. A friend up there had a toyota truck and volunteered to jump me. We connected up the cables, he revved up his engine, I turned my car to pre-glow, he gave me the thumbs up to start her, I turned the key to start and...his truck died! We did eventually restart his truck, but I ended up hill starting the car (yes, you actually can hill or tow start them, although you have to be going about 40 MPH in neutral and then shift into second to crank the engine).

Take home message is to get a nice juicy charged battery if yours is suspected to be no good. You could take the battery to be checked out, and if good, recharge it. A battery charger is a good thing to have anyway. Other suggestion is not to scrimp on the quality of battery cables. Everyone tries to get the cheapoes, figuring that it is just for emergency. Yet it is just in such an emergency that you want really good cables. Large gauge copper cables make a better connection and increase liklihood of a successful jump.

Was the car, an automatic trans? Never heard of po starting an automatic. Thought the torque converter was the reason why. It's supposed to allow the engine, to run/spin independently, of the rest of the systems. Weird...So will my 300CD's do that? They're all autos.

rrgrassi · #12 04-03-2007, 04:00 PM

Quote:

Originally Posted by truckinik

Was the car, an automatic trans? Never heard of po starting an automatic. Thought the torque converter was the reason why. It's supposed to allow the engine, to run/spin independently, of the rest of the systems. Weird...So will my 300CD's do that? They're all autos.

Yes, you can hill or tow start these cars. It's in the MB owners manual also.

Panzermann · #13 04-03-2007, 04:01 PM

Yes, it was a US 1984 300TD AUTOMATIC. But you really have to be going fast (about 40 mph).

truckinik · #14 04-03-2007, 04:06 PM

Wow, That's awesome to know. I've never even opened a manual, for my cars. A few of them, fortunately, came with them, but I never thought about looking at them for any reason....Guess I should..There are likely a few more well kept secrets, and cool facts I'd be interested in...

Panzermann · #15 04-04-2007, 06:59 PM

Quote:

Originally Posted by truckinik

Wow, That's awesome to know. I've never even opened a manual, for my cars. A few of them, fortunately, came with them, but I never thought about looking at them for any reason....Guess I should..There are likely a few more well kept secrets, and cool facts I'd be interested in...

When all else fails, read the directions....