jrundell
08-27-2009, 05:08 PM
Looks like I may be needing a new starter soon, but I do not want to go with a Bosch remanufactured unit.
My question is this -- is there an alternative starter for the E24 that is NEW, and NOT a remanufactured unit?
Here's why:
I have had issues with Bosch remanufactured starters (one "new" and one old) before in a 1973 Porsche 911. But it wasn't until a friend had the exact same issue (in a '69 911 with another "new-reman" Bosch unit), and we eliminated every possible cause except the internals of the starter itself, that I really started wondering and questioning. The problem was, a loud click that was the solenoid engaging, and the gear moving to the flywheel, but no spinning motor. This occurrence was sporadic and unpredictable in the case of my "new" starter, consistent with his. Grounds were cleaned and checked, ignition switches bypassed, voltage drop checked, multiple new batteries tried, connections cleaned and checked....
Also, Bosch, it seems, aren't what they used to be. Their Brazilian built ignition coils (silver in color) are infamous in the early 911 world for crapping out with no warning, and leaving people stranded (it happened to me in a friend's car). It is simply a quality issue. So now, everyone wants the old Bosch coils (black housing), or at least carries a spare.
The link/article excerpt below offers a plausible explanation to the starter issues. Basically, that the 30 or so year old copper armature wiring, which is not replaced in the Bosch Reman process, can cause grounding issues that can keep the motor from spinning.
Opinions? Anyone have this issue? Maybe E24 starter wiring isn't old enough yet to cause problems (but it will be soon). Either way, I'd rather go new and save more potential headaches.
http://www.gowesty.com/library_article.php?id=307
"The original Bosch starter design is actually two cylindrical parts bolted together: A solenoid and an electric motor. The assembly of the two is the "starter". The smaller of the two cylinders is the solenoid, the larger is the electric motor. The solenoid is an electro-magnetic device. Inside this small cylinder is a smaller cylindrical solid iron core with a couple of miles of copper wire.
The wire is wound around in such a way that it surrounds the iron core, but does not touch it. When current flows through the wire, a magnetic field is created which causes the iron core to get sucked up inside the windings thereby creating a pulling force.One end of the iron core is mechanically linked to a seesaw device that operates a "Bendix” drive, which has a small gear on it. That small gear mates with the big gear on the flywheel, which is bolted to the crankshaft of the engine. By pulling on one end of the seesaw, the iron core within the solenoid engages the two gears together. At the other end of the iron core is a big, fat switch. It is through this switch that the electric motor gets power via the big fat wire that is bolted to the starter and goes straight to the battery. So now, with the two gears mated, and power supplied to the electric motor, the engine cranks over. Seems pretty simple and bullet proof.
I started studying the starter circuit and noticed that the solenoid actually has two separate sets of electrical windings. One set is called the “pull” set, the other is the “hold” set. The pull set is much stronger than the hold set, simply made possible by more loops of wire. What is interesting is that the pull set gets its ground path through the windings of the electric motor. The hold windings get a separate ground path directly to chassis ground. So, when you turn the key in the ignition, electricity has to flow through the mile of wire between the ignition switch to the solenoid, then through another few miles of wire that are the pull windings of the solenoid, and then through another million miles of wire that are the electric motor windings. When everything works right, the solenoid pull windings yank on the iron core, which engages the Bendix drive. The other end of the iron core energizes the motor windings. That gets the motor spinning, but in doing so kills the ground path of the pull windings, so the hold windings keep everything going until the ignition key is released. The problem with this design is all the light-years worth of wiring.
My theory is that the resistance of all that wire increases with age. So, when these vehicles were new, the system would work fine for years and years. The reason replacing the starter with a rebuilt one does not always solve the problem is that these rebuilt starters have OLD WIRING in them. When Bosch rebuilds the starter, the motor section just gets new brushes, bushings, and maybe an occasional stator and solenoid. And since these vehicles have been out of productions for so long, BRAND NEW Bosch starters of this design are no longer available.
The solution it appeared was is to replace the starter with a BRAND NEW one of a completely different high torque, gear-reduction design. The design itself is not new, Chrysler products have been using the design since the 50’s. Those of us who have been gear-heads have always wondered why a 1966 Dodge Dart has such a wheezy sound when it was cranked over to start: It’s the gear reduction starter."
My question is this -- is there an alternative starter for the E24 that is NEW, and NOT a remanufactured unit?
Here's why:
I have had issues with Bosch remanufactured starters (one "new" and one old) before in a 1973 Porsche 911. But it wasn't until a friend had the exact same issue (in a '69 911 with another "new-reman" Bosch unit), and we eliminated every possible cause except the internals of the starter itself, that I really started wondering and questioning. The problem was, a loud click that was the solenoid engaging, and the gear moving to the flywheel, but no spinning motor. This occurrence was sporadic and unpredictable in the case of my "new" starter, consistent with his. Grounds were cleaned and checked, ignition switches bypassed, voltage drop checked, multiple new batteries tried, connections cleaned and checked....
Also, Bosch, it seems, aren't what they used to be. Their Brazilian built ignition coils (silver in color) are infamous in the early 911 world for crapping out with no warning, and leaving people stranded (it happened to me in a friend's car). It is simply a quality issue. So now, everyone wants the old Bosch coils (black housing), or at least carries a spare.
The link/article excerpt below offers a plausible explanation to the starter issues. Basically, that the 30 or so year old copper armature wiring, which is not replaced in the Bosch Reman process, can cause grounding issues that can keep the motor from spinning.
Opinions? Anyone have this issue? Maybe E24 starter wiring isn't old enough yet to cause problems (but it will be soon). Either way, I'd rather go new and save more potential headaches.
http://www.gowesty.com/library_article.php?id=307
"The original Bosch starter design is actually two cylindrical parts bolted together: A solenoid and an electric motor. The assembly of the two is the "starter". The smaller of the two cylinders is the solenoid, the larger is the electric motor. The solenoid is an electro-magnetic device. Inside this small cylinder is a smaller cylindrical solid iron core with a couple of miles of copper wire.
The wire is wound around in such a way that it surrounds the iron core, but does not touch it. When current flows through the wire, a magnetic field is created which causes the iron core to get sucked up inside the windings thereby creating a pulling force.One end of the iron core is mechanically linked to a seesaw device that operates a "Bendix” drive, which has a small gear on it. That small gear mates with the big gear on the flywheel, which is bolted to the crankshaft of the engine. By pulling on one end of the seesaw, the iron core within the solenoid engages the two gears together. At the other end of the iron core is a big, fat switch. It is through this switch that the electric motor gets power via the big fat wire that is bolted to the starter and goes straight to the battery. So now, with the two gears mated, and power supplied to the electric motor, the engine cranks over. Seems pretty simple and bullet proof.
I started studying the starter circuit and noticed that the solenoid actually has two separate sets of electrical windings. One set is called the “pull” set, the other is the “hold” set. The pull set is much stronger than the hold set, simply made possible by more loops of wire. What is interesting is that the pull set gets its ground path through the windings of the electric motor. The hold windings get a separate ground path directly to chassis ground. So, when you turn the key in the ignition, electricity has to flow through the mile of wire between the ignition switch to the solenoid, then through another few miles of wire that are the pull windings of the solenoid, and then through another million miles of wire that are the electric motor windings. When everything works right, the solenoid pull windings yank on the iron core, which engages the Bendix drive. The other end of the iron core energizes the motor windings. That gets the motor spinning, but in doing so kills the ground path of the pull windings, so the hold windings keep everything going until the ignition key is released. The problem with this design is all the light-years worth of wiring.
My theory is that the resistance of all that wire increases with age. So, when these vehicles were new, the system would work fine for years and years. The reason replacing the starter with a rebuilt one does not always solve the problem is that these rebuilt starters have OLD WIRING in them. When Bosch rebuilds the starter, the motor section just gets new brushes, bushings, and maybe an occasional stator and solenoid. And since these vehicles have been out of productions for so long, BRAND NEW Bosch starters of this design are no longer available.
The solution it appeared was is to replace the starter with a BRAND NEW one of a completely different high torque, gear-reduction design. The design itself is not new, Chrysler products have been using the design since the 50’s. Those of us who have been gear-heads have always wondered why a 1966 Dodge Dart has such a wheezy sound when it was cranked over to start: It’s the gear reduction starter."