Sparks and smoke, then nut and bolt just spins - starter solenoid to motor connection
 

I noticed some sparks and smoke coming from the wire connecting the starter to the solenoid after cranking for about 5-8 seconds. The wire was hot. I figured it's a bad connection at the solenoid and went to remove the wire to try to repair it (solder). I put the 13mm socket on it and started loosening. But the nut stays put and the threads/stud spin! Though it seem like there should be, there is no bolt head to hold on the back of the solenoid.

Since the stud appears to just spin in the solenoid, I guessing that means something inside the just solenoid broke. Does that mean my entire starter is toast all just for a bad wire and now stud on the solenoid?

FYI
 

SOLENOID SWITCH
MB# 0001523010
$122.00




.

Sometimes you have to take things apart to find out what exactly is wrong...
forensic autopsy.....

FYI
 

The SOLENOID SWITCH is a "multi ton press" sealed unit.

Seriously ? That sounds a little like overkill... ???

Luke, when you take it off... how about sending it to me... ?
I have BIG hammers.....

starter
 

Luke, the starter may very well be ok. It's likely just the solenoid is fried.
There is a pictorial about rebuilding the starter somewhere on this forum.
On the subject of rebuilding, stay away from rebuilt starters from McParts.
Most of there are reconditioned with substandard Chinese and Mexican pieces. You will have problems with them. If you are comfortable changing out the starter, follow the instructions on the pictorial and use the OEM solenoid. Or take it to a re-builder, and insist on OEM parts, Or use a salvaged starter. I'd take a good used starter over a "lifetime rebuilt McParts" starter any day.
Jonj

One good method is to find a farm town with an old electrical repair shop which fixes magnetos and generators and starters for tractors..... they know how to deal with industrial type stuff....

great thanks for the tips guys. guess I have to R&R the starter and probably replace that solenoid.

The car has 180K miles - is the whole starter going to need to be replaced soon anyway? I'd rather not fix it if it ain't broke, but then more importantly, I don't want to mess with again for at least 50K miles.

The solenoid coil and the elec cotacts are sealed by a crimp on the casing therefore no access. Try pulling on the stud while tightening the nut. My guess is there a square which locks the stud internally that has fallen out of place. The solenoid is pretty robust and usually lasts a long long time per a local rebuild shop. What ususally goes wrong with Bosch starter motors are worn bearings. Take yours apart, check the windings for shorts. If no shorts found, check and replace bearings and brushes if needed, clean and lube and you should be good to go.

ps. I recently "rebuilt" a starter and finally had to put it to the test last week when a pin hole developed in the fuel line under the car and sucked air. I must have cranked that starter for a total of 5 minutes without it slowing down (15 sec ea with rests in between). With my old bad starter I was able to only crank 2 x 15 seconds before slowing to a crawl.

Here is a good starter DIY rebuild thread

http://www.peachparts.com/shopforum/diesel-discussion/293895-om617-starter-motor-life-not-just-christmas.html

CHARLIE