Dadio

Any update as to final fix ?

IXLR8

Not yet.

More testing to do when we get together at my friend's shop.

I hope its not the starter. I had all that stuff out to install a new engine compartment cable.

marky522

90% of the time its the harness or the starter. I replaced the bad harness on my car to discover my starter is bad as well. occasionally the engine to body ground or body to battery ground can have some resistance.

Mark

Devil Boy

If you decide to replace your starter, there is a DIY on this forum. I have done this to fix my sluggish hot starts and it's not that difficult.
https://rennlist.com/forums/997-foru...l#post11346593

IXLR8

Thanks Mark.

Having load tested the battery at 320A (1/2 the CCA of the battery) and it held a steady 10.67V, so it can only be the wiring and/or the starter.

I am going to run a load test again at the connection at the transmission and then measure ALL voltage drops, from the battery to that connection and then both ground straps (battery and engine). Cable #14 is new.

IXLR8

Thanks DB.

If that is the case, it'll be a walk in the park having had all the bits out already to get to the starter to install the new cable.

And if it is the old starter, I'll take it apart to see what the cause is.

IXLR8

If it cranks slowly during hot starts, I would agree seeing that only the starter and harness at the starter are subject to heat in the engine compartment.

It ended up being the starter. A new Bosch unit was installed.

I disassembled the old starter and I can see why it ended up being the problem. I'll take pics and then clean all the bits up before installing a new brush plate and cleaning up the commutator. The planetary gear set was totally dry as well.

The faulty starter is original (date code 05-05) and the 997 has a mere 148,470 kms (92,254 miles) on it.

IXLR8

In many cases a replacement starter may not be necessary.

All that the original starter needed was a cleaning and possible replacement of the brush plate.

As removed, the segments in the armature are dirty. The brushes were just as gummed up due to a film of grease and carbon dust from the brushes. The grease was likely from the planetary gear drive that was dry upon disassembly.




Same for the motor housing. A film of grease and carbon from the brushes over time.




All cleaned up and ready for a new brush plate assembly...






Other than the brush plate assembly and cast nose housing not shown, all the bits in a 997 starter...

RBP

Wow that looks better than the new one we installed.

IXLR8

The Bosch carbon brush holder assembly was impossible to find in North America. I called many of the retail and wholesale vendors and no such luck.

I was able to get one out of the UK and had it shipped to Germany for pick-up while I was there.

Bosch brush plate part numbers:
1 004 336 452
1 004 336 852







All put back together and the spare runs like a new one.