Electrical/mechanical weirdness

taylorcom

taylorcom

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Sometimes if my '72 3.0CS has been sitting a while, when I start it up, smoke comes out of the steering column (from over-heating of the black wire that connects to the ignition/starter unit in the steering column).

At the same time, the motor starts up and runs, but make a loud racket, sort of a dry grinding/clattering sound. It really sounds like the motor is eating itself, or a bearing has given out ... quite a loud noise (which I haven't been able to locate the exact source of).

Then I turn the ignition off. After starting and stopping the motor a few times, the smoke and mechanical noise stop ... and the car runs fine.

Any ideas as to what is happening?
 
Stop!

Sounds like an electrical fault in the starter or solenoid. My suggestion is don't keep trying, you could end up with an electrical fire that destroys the whole car if you're not fast enough to put it out. Also if the solenoid fails it could damage the ring gear as the starter motor gear will not disengage and that could be the grinding/clattering noise you are hearing.
I think you should remove the starter motor and have it checked.
 
Last edited:
Solenoid

If the solenoid is faulty, sometimes it will work and sometimes it won't. The noise could be when it is not working and the starter gear is rubbing on the flywheel (ring) gear because the solenoid has not withdrawn it when you release the ignition key. This makes a loud noise similar to what you have descibed.
 
Makes sense. What would explain the excess heat in the black wire where it connects to the starter switch?
 
Starter/ switch

Taylor,

The black wire is getting hot would mean that there's likely a high resistance situation or short. If you have an electrical meter, check the wire resistance and wether there is a short to ground. It's likely that something is touching the body in the column, firewall, or near or at the starter. It may be possible that the switch in the start position is shorting somehow so check it as well.

Best regards,

61porsche
 
I'm wondering ...

... if the cause of the excess heat at the ignition switch (at the steering column) is directly related to the noise (which is probably caused by the starter gear not retracting properly and then rubbing on the flywheel gear). Both symptoms occur at the same time.

Two things can cause wire to overheat, of course. One is a short. Another cause could be a weakened connection, though I see no frayed wire at the point where the heat is strongest (meaning the point at which the black wire connects to the ignition-switch housing).
 
Switch/ Starter/ low voltage

Taylor,

If the resistance or short is such that the voltage drops to the solenoid enough then yes; it may be possible. The solenoid engages the starter gear and enables full voltage to the starter to turn.

To be perfectly clear though, both problems require investigation. The starter and solenoid; and the switch wiring. If the problem persists it can lead to more problems like damaging the teeth on the flywheel.

A meter can check the starter draw of amps which should be listed in the manual. A meter can tell if there's a short in the switch in the start position.

The only other thing on the solenoid/ starter is the wire that goes to the coil only under cranking and bypasses the ceramic resistor. If that wire is shorting, then it too can contribute to your problem.

If you need more explanations, just keep asking.:)

Best regards,

JB
 
This is good info, JB and all ...

... I don't have a voltage meter, tho, but will look for bare wires as u suggest.

Another question about the starter: when the solenoid withdraws the starter gear from the flywheel gear, is this a spring-loaded action (i.e., not electro-mechanical)? Also, can the solenoid be lubricated if it is slow to withdraw?

Thanks,

Steve
 
It engages via the elecromagnetic action and retracts due to the spring tension. I don't think you can remove the solenoid itself to lube it but I may be wrong. There is a hood over the gear that hides it fairly well. Just replace it with the permanent magnet e30 S14 M3 starter, Bosch SR-440X. It's smaller and lighter.
 
Starter solenoid

Taylor,

The solenoid action requires it to be clean; the opposite of oiled or greased. Yes, the solenoid is removable, but what once was easily obtained may not be now without purchasing the starter assembly. What usually happens is that the connections get burned a bit and sometimes you can just clock them 180 or clean it well.( the copper bolt on the inside action part of the solenoid.)

Absence a meter, check the starter connections per the connections in the repair manual and tightness, for any thing touching the black wire. or frayed, melted, insulation.

Any auto parts place should be able to check/ test your starter for amp draw for free in hopes that it needs replaced and you'll buy from them.

Best regards,

61porsche
 
R & R'ing the starter

Thanks, all,

I see in my records that I replaced the starter in Sept. '05 with a rebuild ($80) from a shop I've used a lot over the years with good results.

That was 5 years ago, of course, but not so many miles ago since I don't drive the car that much ... maybe 1K-2K miles/yr., if that.

Removing & replacing the starter sure is a pain ... lots of odd angles to get around in the engine compartment, but I guess if it needs doing I'll have to do it again.
 
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