Causes of Camshaft deviation other than IMS
 

What could cause Camshaft deviation to fluctuate on one side other than IMS issues?

IMS drive sprockets that have slipped on the drive tube are the most common.

Fluctuating Cam deviation
 

Is this something I shoudl be concerned about. IMS was replaced with LN bearings but I am getting a + or - .3 fluctuation on one side.

Spec is +/- 6 degrees

Having the same issue. I was throwing a solid CEL and 1531 code, meaning variance on Bank #1. I assumed it might be the IMS, since I got the car over a year ago with no maintenance documents. Had no idea if it was ever done. Just finished putting the new IMS bearing in and the old one looked fine. No wear apparent, but it was filled with engine oil, so just a matter of time. I feel better knowing what's in there now.
When I locked it at top dead and put the cam lock on, everything lined up perfect. Where might the deviation be? Wear pads?
Getting ready to button it back up, check cam timing again, and give it a go.

Unusual cam values could be a number of things; wear pads, chain slop, weak tensioners, VarioCam components going south, bad position sensors, etc.

That said, P1531 is usually associated with a failing VarioCam actuator on bank 1 however.

here is the best picture i've ever seen regarding chains, ims, tensioners, paddles, etc.; also does a good job of explaining the various ims flanges out there:

http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/Gp1800.pdf

That makes sense, bank 1 could be holding back while bank 2 is ramping up. Would definitely give a wide variance number. I'll head that direction.
No way to test the actuator without the PST2 scanner is there? I have a standard OBDii scanner. That will only tell me where the problem is, not what's causing it.

durametric will do it.

P1531 indicates that the actuator is triggering, but that the cam is not assuming an active position on Bank 1. Usually, this requires replacing the actuator, assuming no wiring issues. P1539 is the equivalent code for bank 2.

So that tells me (barring wiring problems) that the solenoid is firing, the actuator is hanging up/ not engaging the whole way?

Most likely.

Then the faulty actuator won't cause a variance that could hurt the engine, just performance. I shouldn't have a problem clearing the code and giving it a run or two to check it out. I think it takes about three cycles to throw a new code, right?

Actually, I would not be driving the car in this condition. Besides throwing codes, one side of the engine is running under cam position conditions that are different than the other side. While it may not cause bigger problems for some time, it ain't really a good thing...

I agree for sure. I'll be fixing it right away (wife wants her daily driver back). I just want to run it quick to check out the IMS repairs I did. Actuators aren't rebuildable other than the wear blocks, are they?

The VarioCam actuators are not rebuild-able, and are separate from the wear pads on a five chain motor, but it would be a good idea to replace the wear pads while you have the system apart; they are a “consumable” item not unlike brake pads.

not that i would wait for it but, would the deviation cause a CEL to illuminate and if so, at what point could that be expected to happen?

@Tony- That's what started my quest. I had a solid CEL and when I read it with the scanner I got a P1531, meaning a cam variance on bank #1 that was outside of tolerance. I'll be heading into the variocam next...
BTW, I'm at 120k now, but the car was purchased without documentation, so I have no idea what was done in the past.

gary_d: any idea what your current deviation number(s) are?

Unfortunately, I don't. I only have an OBDII scanner to tell me there's a fault Trying to line up with a PST2 or Durametric right now to delve further.
JFP says the acceptable is +/- 6 degrees though, so if you have access to the correct scanner you'll know if you're in tolerence.

Is the cam deviation measured just at idle or through a particular rev range?

i know i'm not in spec, that's why i was curious at what point it triggers the CEL

position 1: -8.80º
position 2: -5.64º