Variocam Plus

[tac27]

2003 996 C2 Cabriolet

I've searched thru the forum trying to discover the acceptable range of the 'camshaft position deviation' for a Variocam Plus.

I've found a post discussing a +/- 6 value, but the post was about a Variocam, not a Variocam Plus; is the value range the same for both? I also found several PDFs posted, which were really great, but I didn't find a listed acceptable value range.

This is the reading I've gotten from the Durametric:

Bank 1 is .46

Bank 2 is 2.81

The values remain consistant despite variation in RPM or temperature; are they within the acceptable range?

Thank you,

Tim

Las Vegas

[george996]

Tim,

I have the manuals and could not find the allowable range for Variocam Plus. The +/- 6 is for Variocam like you mentioned.

My 2004 has a bank 1 deviation of 4.14 and 0.39 for bank 2. The DME diagnostics will check the deviation and report a fault code if there is a problem. There are a handful of fault codes that deal with cam postion however it looks like P0011 and P0012 are the most relevent .

George

[tac27]

Thanks George!

[Porschelibrarian]

Isn't that one of the problems that is leading to the catastrophic engine failure on the 996 engines? When the deviation doesn't match but is not enough out of range to throw a code so one keeps driving until ........... Also check if the deviation is the same at idle after reving the engine a couple of times.

[JFP in PA]

Isn't that one of the problems that is leading to the catastrophic engine failure on the 996 engines? When the deviation doesn't match but is not enough out of range to throw a code so one keeps driving until ........... Also check if the deviation is the same at idle after reving the engine a couple of times.

Actually, no. Theoretically, camshaft deviation values should be zero, but in the real world they never are, and you usually end up with some weird +/- values due to tolerances or wear. Even very carefully assembled engines that have gone through very carful static cam timing show this type of discrepancy.

As far as being a predictor of a pending catastrophic engine failure, the only indication that is happening that I am aware of is when the deviation values dance back and forth at an idle; or during a transition from throttle open to closed takes place. Even then, the movement of the values is quite pronounced, indicating that something that shouldn't be moving around is doing just that, usually the IMS bearing.

I believe the accepted deviation value limit, VarioCam or VarioCam Plus, is +/- 6 degrees, and is based upon how far out a cam would be if it were installed one tooth off, which would be the same for either type of cam control system.