Camshaft positioning sensor deviation?

[jditom]

I used my Durametric software to measure both CPS deviation.

#1 1.34
#2 0.35

The book says they should be zero? Does this mean they should be the same number?
Or they should not fluctuate?
They don't change and I have been checking them once a week for a month.
Waynes book mentioned it as a way to pick up a early IMS failure?

Any thoughts are welcomed.

2004 S anniversary ed, 22,000 miles

[Wayne 962]

Yes, in an ideal world, the deviation should be zero. They almost never are though. What you really want to look for (and I apologize, this wasn't clear in the book), is for the deviation not to fluctuate at idle. If the camshaft deviation is bouncing around at idle, then you're seeing a weak / loose intermediate shaft and the timing is changing back and forth. That's bad news.

If the deviation between the two camshafts stays steady at idle and doesn't bounce around, then you're pretty good. Since your numbers are not changing, then it sounds like your bearing is fine. Your camshaft timing is off slightly, but it's very slight (that actually may be within the spec, I don't have the Porsche specs handy here on my desk). Doesn't sound like you need to worry.

-Wayne

[jditom]

Wayne,

Thanks for the reassurance, I will sleep better now.

I plan on doing an IMS upgrade but not until next winter.

PS Got your book for x-mass and I bought 2 more for friends.
Great work!

John

[Wayne 962]

Originally Posted by jditom

PS Got your book for x-mass and I bought 2 more for friends.
Great work!

John

Cool, be sure to make the correction to the book on page 81! (101 Projects for Your Porsche Boxster: Corrections & Updates)

-Wayne

[teknow]

Wayne - an avid user/reader of the book, which is evident by the amount of oily finger prints down the side. Brilliant job, keep it up.

I used Durametric on my MY2000 Boxster S this morning. Anywhere between -5.83 and -6.23 on Bank 1 and 0.00 constantly on Bank 2.

There is no fluctuation at idle and the car is running well with no noticeable issues. No faults in the memory etc etc.

So I'm not so worried about IMS failure any more but am curious as to what the "norm" is and when I should get worried?

Any advice you can throw would be hugely appreciated.

[mattatk]

teknow,
Did you manage to solve your camshaft deviation issue? I have a similar scenario with bank #1 at a steady -8.02 & bank #2 at a steady 0. I am suspicious of the 0 reading

[ChrisJP]

-8.02 seems out of tolerance (±6deg).
If you have a RoW car, you have only one sensor so 2nd reading is always at 0 (position 2 deviation & actual angle for bank 2).

[mattatk]

Ahh, yes ROW car (well Australian, is there a way to check it's ROW?). How come the ROW cars only have 1 sensor? Are the sensors hard to remove/get at? I'm wondering if I could move the sensor over & fit it to bank 2 to check that side as well (could help check if sensor is faulty?).
Cheers
Matt

Also, if timing has slipped (& in my case, very steady deviation), what tends to be the usual culprit?

[adbm3]

Fooled around with the Durametric yesterday looking at the cam shaft deviation on my 2000 S. Cam shaft 2 stayed at -4.89 from cold to full operating temperature. However, Cam Shaft 1 started out at -4.81 and then dropped to -3.81 as the engine warmed up to operating temperature. This change was not at all erratic. In fact, it only dropped by a few hundredths after each rev and then stayed steady. I stopped reading after the car hit full warm so I have no idea how low it would have dropped thereafter. This doesn't strike me as problematic - only the timing changing to maximize efficiency as temperature rises. But, would like a more expert opinion.