So, my 300D just tried to take itself out - PeachParts Mercedes-Benz Forum

KAdams4458 · #1 01-21-2009, 06:13 PM

In preparation for replacing the windshield in my wife's Kia, I installed a temporary manual control switch and relay for the glow circuit so that I could start the 300D and move it out of the heated side of my shop. I only cranked the starter for about five seconds after a 30 second glow, and could tell that the battery was too low to spin the engine fast enough, so I turned everything off and wandered off to the other side of the shop in search of my battery charger.

By the time I got back to the car, I smelled smoke. At around the same time I decided to be very quick about disconnecting the battery, I saw smoke coming from the starter, and by the time I had the battery disconnected, there were flames coming from the starter!

Stupid me has not yet purchased a fire extinguisher for the shop, so all I had to fight the flames with was my fresh $5 mocha - Thankfully, the mocha worked!

So, it looks like I now need a new starter and some wiring. Oh, and I'm a little under-caffeinated, so I could use a replacement mocha, too.

While I'm at it, I should probably stock up on some fire extinguishers for the shop. This experience was way too close for comfort!

Now, I have no idea what caused this, but it cannot be blamed on the glow circuit, so don't go there. Something in the starter seems to have simply shorted the last time it engaged, and was just drawing oodles of current without the key in the ignition, much less the starter being engaged. How this could possibly happen I do not yet know.

I'm gonna go breathe in to a paper bag for a while.

cphilip · #2 01-21-2009, 06:18 PM

Mine was successful on her first attempt. Glad you got it out!

TheDon · #3 01-21-2009, 06:20 PM

if it was me I would have rolled it out into the middle of the street and let it burn.. mine's fully insured

LuckyEddie · #4 01-21-2009, 06:25 PM

I have the starter harness from the fender well to the starter if you need it. 82 300SD (might fit) and shipping should not be that bad.
Robert

cphilip · #5 01-21-2009, 06:25 PM

Yea... and then your insurance company will offer you $1500 for is since they can find so many ones in that price range on Craigs list... and then the fun begins!

You don't want to rely on insurance if its simple insurance. If its not special insurance for an agreed upon actual value... You will lose if you have any effort and work into the car. They don't value them like we do.

imagesinthewind · #6 01-21-2009, 06:26 PM

Dern, glad you didn't decide to take a leak or something to find that your car AND shop go up! Glad you got it out fast!
Good luck changing the starter.

patbob · #7 01-21-2009, 06:32 PM

Quote:

Originally Posted by KAdams4458

Now, I have no idea what caused this, but it cannot be blamed on the glow circuit, so don't go there. Something in the starter seems to have simply shorted the last time it engaged, and was just drawing oodles of current without the key in the ignition, much less the starter being engaged. How this could possibly happen I do not yet know.

Wire down by the starter may have overheated in the start attempt and melted the insulation off, then shorted. Or maybe the starter relay just stuck on and there wasn't enough juice to keep turning the engine over so you didn't notice. And then there's the mouse theory -- the (now carbonized) mouse continued to conduct

If it was one of these, it should be obvious when you get the old starter out -- they'll either be burnt wiring connecting to the starter or inside it, or a spare charcoal mouse.

Ok, mouse isn't really likely, its been a long week and my dark humor is showing, but maybe one helped the insulation fail.

KAdams4458 · #8 01-21-2009, 06:33 PM

Well, as my car isn't driven at all at this point, there is no insurance on it. Besides, even full coverage would probably pay me all of $500 for the car, and I've installed over $1500 in parts on it, and have only put about 300 miles on it since buying it. Then there's the little problem with not being able to roll it far enough away from the shop/trees to do any good. I like my 1600 square foot shop, and really don't want to lose it, or the contents.

I'm very happy not to be the newest member of The Flaming Diesel W123 Club, thank you!

Hatterasguy · #9 01-21-2009, 06:34 PM

Quote:

Originally Posted by TheDon

if it was me I would have rolled it out into the middle of the street and let it burn.. mine's fully insured

Yeah that would certianly be a viable option.

KAdams4458 · #10 01-21-2009, 06:37 PM

Quote:

Originally Posted by LuckyEddie

I have the starter harness from the fender well to the starter if you need it. 82 300SD (might fit) and shipping should not be that bad.
Robert

I'm pretty sure they are different, but I'll check. Anyway, the new wiring should be very expensive, either. Thanks! I'll let you know if it will help.

KAdams4458 · #11 01-21-2009, 06:42 PM

Quote:

Originally Posted by patbob

Wire down by the starter may have overheated in the start attempt and melted the insulation off, then shorted. Or maybe the starter relay just stuck on and there wasn't enough juice to keep turning the engine over so you didn't notice. And then there's the mouse theory -- the (now carbonized) mouse continued to conduct

If it was one of these, it should be obvious when you get the old starter out -- they'll either be burnt wiring connecting to the starter or inside it, or a spare charcoal mouse.

Ok, mouse isn't really likely, its been a long week and my dark humor is showing, but maybe one helped the insulation fail.

If I had been cranking on it for a long time, or even made several attempts, I might suspect insulation failure and cable shorting as well. One relatively short cranking session shouldn't have caused a problem, but you know, this car was owned by morons in the past, so who knows what I will find. Maybe I'll be lucky and find that the starter is not to blame, and it was instead some stray bolt or rodent that fell across the connections. once the fire was out, it wasn't lit well enough down there to see!

I'll take a peek at things once the undoubtedly toxic smoke clears.

cphilip · #12 01-21-2009, 08:23 PM

Quote:

Originally Posted by KAdams4458

I'm very happy not to be the newest member of The Flaming Diesel W123 Club, thank you!

Yep. This is a club you don't want to be a member of. Very few of us and we hope to keep it that way!

The importance of a fire extinguisher and a battery disconnect keep hammering their own points home.

KAdams4458 · #13 01-21-2009, 10:14 PM

Well, the cables had nothing to do with the fire. What I found once I got a good look at things is that the solenoid caught fire. The black plastic housing on the terminal side of the solenoid has been cracked in the past, and has globs of black silicone sealant patching it together...

@*%# previous owner!

Is it just me, or are previous owners one of the most dangerous things for these cars? All it takes is one moron to turn these fantastic examples of engineering in to a pile of junk!

Okay... So a solenoid is over $100 locally. Anyone have sources for more reasonably priced solenoids? I can tear down a starter and overhaul it while I'm at it, but it's pointless if I can't find a quality-made solenoid that hopefully doesn't cost an arm and a leg.

pawoSD · #14 01-21-2009, 10:50 PM

Don't the original solenoids have a steel casing....I am pretty sure....?

P/O's do some scary stuff. We righted a lot of wrongs by replacing the motor in my dad's 300SD when we got it (motor was blown). Found all kinds of ghetto repair work on that poor engine. Now everything has been set right with the new motor in though. Thankfully!