[Walt Fricke]

The CHTS can cause starting problems. But not "no crank" problems.

When starters get worn, they sometimes have a bad segment on the commutator or whatever the segmented connection is, where brushes bear on it (or brushes can get very worn). If the starter stops on such a segment, it may fail to conduct current when next called upon to do so. Heat seems to exacerbate this, and the solenoid ground (or is it the positive) is through this. So nothing, not even a click. On my VW bus I used to crawl under and reach up with a screw driver to short the big positive terminal on the starter to the one on the solenoid. This would cause the starter to whirr, but not engage. Then I'd jump in the car and turn the key, and usually it would start up just fine. If not, repeat the process.

A 911 doesn't have enough ground clearance for that, and taking the starter out and to an auto-electric shop for testing and repair or replacement is the way to go.