The next morning attempted to crank the engine and you guessed it…no starter engagement.
I did get a click from the glow plug relay and the head lights worked fine.
Jumping the starter solenoid directly produced no activation of the solenoid.
I figured the solenoid was sticking, so out came the starter.
One of the two starter bolts had been installed gorilla-tight but finally broke free,
only after I climbed into the engine bay to get more direct pulling force on the ratchet handle.
On the W116 300SD, the starter removal from below requires a bit of disassembly.
A two-by-four, strategically placed between the PS shock tower and the turbine housing,
let me shift the engine over just enough to remove the starter from above.
With the starter out, the reason the solenoid wouldn’t activate was plainly obvious.
The braided copper cable going from the starter to the solenoid was touching the bare
metal of the motor housing just enough to cause intermittent failure of the circuit.
Repositioning the braided copper cable to clear the motor housing enabled the solenoid to engage properly.
I consulted with my independent mechanic.
He recommended I replace it with a Bosch rebuilt starter.
He explained that the early OM617s initially came with weak solenoids with a high failure rate.
Bosch upgraded the solenoid specifications which solved the problem.
He said many aftermarket rebuilders don’t use the correct higher spec solenoid and the rebuilt starters fail prematurely.
I’ve read where the high current draw from a poor solenoid can also cause early failure of glow plug relays and neutral safety switches as well.
A new NSS was just installed (to pass the lamp inspection – the reverse lights were out from the failed NSS),
and the glow plug relay was replaced due to a melted housing and a melted clip on cover.
A rebuilt Bosch starter with the good Bosch solenoid was ordered (at cost
)...problem solved.
The core was not accepted as rebuildable by Bosch, so I did end up having to pay a $75 core charge after the fact.
Well, now I have the old one which still functions, unless some one needs a cheap replacement starter??
Send me a PM if you need my old starter.
With the new starter I was finally able to get compression reading and the results are pretty decent:
cyl-1 400psi, cyl-2 360psi, cyl-3 360psi, cyl-4 370psi and cyl-5 360psi.
Took her out for a spin with the new 315 injectors and she seems a lot peppier.
Next maintenance tasks are glow plugs and flex discs.
I have new French Bosch Duraterm glow plugs (Bosch 0 250 201 039) and front and rear MB flex discs (MB 126 410 02 15) on hand.
I’ll post more updates as they get done.