400i: starter solenoid

Well it finally happened... I turned the key and nothing more than an ominous click. (you can hear the solenoid "try" to engage). Actually, this is a regular occurrence on my car, but usually after 2-3 turns of the key the starter engages and she springs to life; it doesn't seem to matter whether the car is warm or cold. Different today. Started fine cold, drove down to the gas station, then wouldn't start again even after about 10 turns of the key. (always great to get an admiring onlooker to help you PUSH your car out of the gas stall and into a nearby parking space!).

Finally, after several more tries, she sprang to life. I immediately ran to a friends house and put her up on the lift. We spent the better part of the day trying to convince ourselves that it isn't the starter solenoid:

-confirmed continuity across ignition switch.
-confirmed 90% starting success when ~13.5v is fed directly to the solenoid

Battery is new, and we confirmed all leads and grounds. It seems that under normal circumstances there is just not enough current to slam the slug in the solenoid all the way through; yet, when more current is supplied the solenoid slams through and starts fine.

So, unfortunately, we're thinking again that it is the starter solenoid. Do the inner workings on these corrode over time or get otherwise 'gunky?' Is there a way to lube the solenoid, or is it a remove & replace operation? BUT HOW THE HECK DO YOU GET TO THE THING??? It was hard enough just getting power directly to it, but to try to actually remove it is another story altogether. Has anyone tackled this project?

Thanks!

Brennan

 

That was one of the first things we jumped to... but there is no starter relay in the 5speeds though. There is just a jumper where the relay would be. Pulled the jumper out and cleaned it.

Also, I should mention that when we fed ~13.5v through the ignition switch, it started nearly every time too.

 

Thanks for the step-by-step! This begs the question of whether I should go ahead and replace the entire starter as long as I have it out rather than just the solenoid. Has anyone had the starter iteself go out? (I'm at about 39,000 km on the dial).