After returning home, I thoroughly checked the entire starting circuit, and found no detectable fault. Discussions with other knowledgeable owners made me suspect that the starter itself was the culprit. Starters often show indications of impending failure during high temperature operation, when electrical resistance is higher. I decided to replace the starter with a Hi Torque unit.
If you need a new starter, you may wish to install a Hi Torque unit (Figure 1), especially if your engine is hard to start or has increased compression.
This new starter also has improved electronics for more reliable performance. As you can see, the starter motor is only slightly larger than the solenoid. You can see more information about this starter in our online catalog.
Removing the starter is straightforward and simple. Begin by disconnecting the battery ground strap. Then jack up the rear of the car, and place it on jack stands. (Figure 2) Make sure that the car is held up securely, because you will be working underneath the car.
The starter is located directly above the inboard CV joint of the right axle. (Figure 3) It may initially look difficult to access, but it is not. Pull off the two yellow wires from the spade connectors on the starter solenoid. Remove the nut from the main terminal on the solenoid, and remove the battery (25mm black wire) and alternator (10mm red wire) cables.
Next, the two "flanging nuts" as Porsche calls them must be removed. These are special 10mm allen-head nuts, so you will need a suitable allen socket and extension. To remove the top nut, reach over the top of the transmission. (I find this easiest when lying on my back, head toward the front of the car, and reaching over the transmission with my right arm.) Then you can take off the bottom nut, and remove the starter.
Now you are ready to install the new starter. Thoroughly clean the ring terminals on the end of the battery and alternator cables to ensure good contact.
The Hi Torque starter has only one spade terminal. Both of the yellow wires are connected to this, using an adapter (Figure 4). The larger (2.5mm) yellow wire carries the control signal from the ignition switch. The smaller yellow wire (.5mm, may also have a colored stripe) activates the cold-start injector when the starter is engaged.
The new starter will fit only one way, with the main terminal of the solenoid facing up. If you try to install it otherwise, the solenoid will interfere with the transmission housing-rotate the starter 180 degrees to the correct position. After it is in seated, replace the two "flanging nuts". Reconnect the red and black cables to the solenoid main terminal, and the two yellow wires as described above.
The flange on the Hi-Torque starter is somewhat thinner than the stock starter; therefore you will need to install some washers before installing the flanging nuts, so that you don't reduce the depth of insertion of the allen wrench. I used four 10mm washers with a total thickness of 7.5mm for a correct fit. This is what the starter looks like installed. (Figure 5)
With more than 700 ft/lbs of torque, the Hi-Torque starter really spins the engine, and makes a significant difference in startup. It is also considerably lighter than the stock starter. This is a nice upgrade that will increase the reliability of your Porsche.