Cam chain actuator guide diagnosis and repair

[woodenewe]

I posted this topic on the Rennlist Discussion Forum, and re-posting it here hopefully to get a definitive answer on continuing to drive my 1999 911/966 C4 with 84K miles:

My car was run with the system tester at an indy shop and diagnosed with a "worn cam chain actuator guide", as determined by reading out "9 degree timing error". The recommended repair is to replace timing chain guides which involve "removing frame bracket, heat shield, and cam cover, replace timing chain tensioner blades, refit cams and set timing".

I subsequently purchased the Durametric software to read out the faults codes: none logged.

The "Camshaft position 1 deviation" was -8.89 degrees and "Camshaft position 2 deviation" was -4.68. Both values did not change with variation in enginer RPM. At idle of 700 RPM the "ignition angle" varied from 6.00 to 8.25, "loss adaptation idle" was -2.14 to -2.23, "ignition timing" was 2.5 to 2.6, and "actual angle for camshaft" was 0.06 to 0.34.

Hopefully someone can look at these numbers and tell me if I have a problem. The car runs well, and no faults found in the memory. I plan to run the car a bit and in a few days, see if there are any changes. If anyone would like more data, I can download it into a PDF file and email it upon request.

Thanks for any help...