solenoid or relay problem ??

[jdowty3]

I know many of you have dealt with starter issues so I'm looking for advice.
My 83SC has developed a problem with the starter when hot. I turn the key, no click, no whirr, no starter noise of any kind. I figure the solenoid is having a problem and the starter will need replaced eventually. I'm getting back on my feet after a 9 month layoff in the IT world so a new starter isn't feasible yet.
Short term, I got a starter relay from Pelican to see if that might help. Problem is when the relay is hooked up, the starter does not dis-engage when the key goes back to the run position. Not only does the solenoid stay energized but the starter motor stays energized and accelerates the motor. Needless to say, I shut it down quickly and have disconnected the relay for now. Tom at PP thinks it is a sticking solenoid. I may try the hammer test this weekend with help from the wife.
Why would the solenoid stick with the relay but never stick without it?

[Early_S_Man]

Jim,

If the contacts in the ignition switch are dirty, or the various Faston connectors ... installation of the relay would boost the Voltage presented to the solenoid significantly, and perhaps increase the solenoid displacement to the point past where dirt, carbon wear particles, tec. were built up on the plunger! Sticking definitely could be the result, though a fairly rare occurance.

My suggestion is to remove the starter, disassemble and clean both solenoid and bendix mechanism inside starter motor with Brakleen or similar solvent. Inspect brushes and bushings for excessive wear ... replace as needed with parts from local motor rebuild shop. Lubricate thoroughly with Valvoline SynPower Synthetic Grease with Moly #986 or #985, and re-assemble. I have done this procedure on many balky Bosch VW and Porsche starters, and it usually assures a couple of years of trouble-free operation!

[Superman]

I recently had this problem with my starter. It developed over several months and had been a rare occurrence but when it become unreliable I removed the starter, took the solenoid off, disassembled the starter. The bendix mechanism was pretty clean, and the starter looked very good inside. I cleaned everything up. Could not disassemble the solenoid without dealing with the solder. I kept this and am likely to disassemble it at some point, clean and use it as an emergency spare. In the meantime, I got a replacement solenoid ($30 or less). I went with the Bosch unit rather than the aftermarket one. I think the Bosch unit was cheaper anyway. Problems solved. I'd recommend inspecting the starter motor and rebuilding or getting it rebuilt if necessary, but nine times out of ten this is a solenoid problem exclusively.

[jdowty3]

Is there a high-torque VW starter that fits the 915/SC? I've read a couple of references but can not find any details regarding a model number.
I will have to wait on removing the starter until at least next weekend. How do you get at the top barrel nut with enough torque to break it loose? I've never removed a 911 starter but have heard they can be a real bear.

[Superman]

Raise the car and support it securely. Lie on the floor directly under the engine and tranny with your feet under the rear bumper. Reach your right hand around with the tool and you will have easy access to that nut. In other words, you "bear hug" the tranny.

[jdowty3]

I didn't think the solenoid was removable from the starter for replacement unless you de-soldered two contact points.