Starter Failure

[randywebb]

How many people have had a Tilton type (Light weight) starter fail?

Mine did & it only had a couple hundered miles on it -- maybe 50 starts. It looks like the gear did not retract back into the housing like it is supposed to.

Fun afternoon crawling under there, but could have been worse - it left me stranded at the painter's shop -- which is right next door to the mech. shop where I work on my car.

[MobileWrks]

best thing to do,is just stick with bosche. I had a few after market starters fail. "Boy did i hear it"

[RoninLB]

how does the starter teeth look?

maybe an alignment prob.. if so it will remain when using any starter.

[emcon5]

Funny this should come up.

In the beginning of December my stock starter died, after 23 years of faithfull service. It died on a weekend, and for sake of convenience, I replaced it with a Bosch starter that was rebuilt by a commercial rebuilder (In SoCal, I think). My local parts house had it in stock, my car is my daily driver, so I went for it.

It lasted just over 2 months, giving it's last gasp yesterday. It has a 1 year warranty, so all I was out was time, but the strange thing is the failure mode was the same as when the stock unit died: It didn't have enough torque to turn the engine over. The parts place put it on the test bench, and it acted normal, it just didn't have enough power to turn the engine. It almost seemed as if the battery was dead, except the battery is only a year old, tested good, and the volt meter read just over 12 volts. I put a replacement on, (the same thing, unfortunately) and it fired right up.

The battery terminals are clean. The starter terminals are clean. The ground strap on the tranny isn't new, but I cleaned it really well when I rebuilt the engine at the end of 2003. The alternator was rebuilt by a local shop 6 months ago. The engine is a short stroke 3.2, 9.8:1 compression, ignition timing at idle is ~10° BTDC, everything else is pretty much strock. The teeth looked fine in both.

I think I just got unlucky with the starter, but I am open to the idea that there may be a problem with the car causing it, I just can't imagine what would cause a starter to die in such a short time. I would guess it had 150 starts on it, 200 tops. I really want this one to last longer than 60 days.

Any ideas?

Tom

[Driver Ed]

A couple of things can kill starter motors quickly. One is misalignment (I used to have a Triumph Spitfire that ate starter motors for breakfast until I finally got the shims right!) but that's not likely to be a problem on your car. The second is if the starter fails to disengage from the flywheel immediately after the engine starts. The Porsche starters have a built-in overrun clutch which allows the pinion gear on the starter to run faster than the motor armature, but only briefly.

If you have a sticky solenoid or a bad ignition switch, it will kill the starter over a short period of time. I suspect you'd be able to figure out if this is happening by disassembling the starter yourself and looking at the overrun clutch and the motor brushes. Also, you might ask if the rebuilder replaced the solenoid or just reused an old one.

[emcon5]

Originally posted by Driver Ed
The second is if the starter fails to disengage from the flywheel immediately after the engine starts. The Porsche starters have a built-in overrun clutch which allows the pinion gear on the starter to run faster than the motor armature, but only briefly.

Now that you mention it, when my first starter died, it was slow to disengage for a couple weeks before it failed. The second one didn't have this problem. This makes me feel a bit better that both didn't die the same way.

If you have a sticky solenoid or a bad ignition switch, it will kill the starter over a short period of time. I suspect you'd be able to figure out if this is happening by disassembling the starter yourself and looking at the overrun clutch and the motor brushes. Also, you might ask if the rebuilder replaced the solenoid or just reused an old one.

I considered taking it apart to have a look, but that certainly would have voided the warranty.

How can a bad ignition switch kill the starter?

Tom

[Driver Ed]

Oh, I didn't notice there was a warranty involved.

A bad ignition switch can cause the starter motor to fail because it's the switch that is responsible for providing power to the solenoid and starter. If you think about it, you'll recall that when you start your car you turn the key all the way and then let the spring in the ignition swtich back it off a notch (disengaging the starter) when the engine starts.

This all happens very fast and it was probably a long time ago when you learned all of this so it's entirely unconscious now. The problem can occur when the contacts for the starter motor don't disconnect when you release the key, or if the spring is broken. It's never happened to me on a Porsche (yet) but I have had it happen on other cars, and if you don't notice it, it's a sure way to kill a starter in a hurry.

[randywebb]

The guy that looked at it with me said the gears didn't have the same sort of cut on both sides that other (stock?) starters do - I didn't have my glasses so I couldn't see. He said that might increase the chances that these things will hang up and not disengage.

I did note an unusual amount of wear on the gear. I can't remember now whether I used anti-sieze on the gears or not. I suspect not. I know I didn't put anti-sieze on all the flywheel teeth.

We'll see how much it will cost to repair - a new one will cost $250.

It's nice that the above poster got a warranty - I didn't think you could get a warranty on an electrical item like this.