Hi,
This past summermy partner and Ijust bought an '82 300D that's already been converted to have an additional tank for veggie grease.As thetemperturedropped we had issues starting and had to have the car towed to a garage where once the mechanic gotitstarted we filled the tank with diesel and fuel conditioner, anti-gel and an assortment of medicines that shouldassureof it starting.

Weplug the car in every night butabout a week ago, on a not tooparticularly cold daymaybe 35 degrees the car refused to start, going from a hopeful chugging sound to dying to a click click after about 10triesand now it sometimesdoesn't click at all.

Wehavereplaced the battery and glow plugsin the past3 months, anddont know what to do exceptto try to warm up the car.

Helpless,
Old Blue

 

When you mean chugging sound the engine was trying to turn over, but now it won't even do that?

 

Are you getting the normal yellow glow plug light that comes on after the key is turned to "on" and stays on for 20-30 seconds?
If the glow plugs are new, then something to check would be the glow plug relay. My car starts at 20 degrees with the new glow plugs (84 300SD)

diesels are harder to start then gas cars, so you have to be easy on the starter/battery, just trickle charge the battery if you know its in good shape

 

Yes, the chugging has stopped which means i guess, that the car won't even turn over anymore. We tried again on a 40 degree day like yesterday but I got no sound from the ignition.

The glow plug light only comes on the first time I try to start. If I try to start it a few more times right after that, the light fades and the buzzing sound that comes on when you have the door open and have left your head light on comes on whenever I turn the key to "on."

I think we'll have to take it back to the mechanic again but don't know exactly what's wrong and how much it should cost.

 

I think your best bet would be to first replace the glow plugs with Bosch or an equivilant brand. But not autolite! Then move on to checking each glow plug individually with a multimeter reading OHMs for accurate current. I think they should read '1' or something close.On the glow plug relay there are two connectors, a big one and a smaller one.

If you remove the big one and look at the female connector parts, there should be numbers listed next to each hole which represent each cylinder. 1 is the first cylinder glow plug closest to the front bumper, and whatever is the highest number is the cylinder's glowplug that isfurthest away from the bumper near the firewall.

When all those are tested and have a voltage of '1' then you don't have a short and you can reconnect the plug back into the relay. After that you want to check your glow plug relay fuse, should be a black box on the driver's side mid way. Visually inspect the strip fuse, if it's blown in half or bent, just change it out with a new one. Don't try to bypass it with copper wireor jimmy rig with some material to it because you could fry the entire wiring harness [&:].

Then after the glow plugs are in, the fuse has been checked, the battery is charged and good, I would suggest testing the relay itself. Idk what the relay is supposed to read, but you should be able to find it here or online somewhere.

That's a great place to start too, especially if the engine is not turning at all. There's a chance that the relay isn't sending power to the glow plugs at all.

Your car should be able to start in any weather. My 190D recently had a starting problem and after fixing it I'm able to start it in 18 degree weather outside. It starts the first try, though it's cold as **** inside the cabin. Too bad the heat doesn't kick in as quickly as the car's engine starts. haha