Camshaft Deviations - Options?
 

Hi guys - I have my 2001 S with an Indy that will be performing some suspension upgrades. While the car is there - I had him pull the camshaft deviations as I’m thinking about doing the IMS and researching which options I should go for.

I had checked camshaft deviations in March of this year and they were 1: -5.66 and 2: -5.80.

This time - they came back 6.0 and 6.2. Slightly out or at spec (I forgot to ask if the changed throughout the rpm range and if they did the reading when engine was hot). The Indy shop doesn’t tear into engines (only air cooled) but did say this is something that I should look at - and would be leary about driving hard. I asked what he thought my options are - he said honestly, given age of car - and the resale values - I should think about selling. I was a little surprised by that given what I read here - I was under impression replacing cam pads and tensioner could correct the deviation numbers and bring them back to spec?

But perhaps given the cost of an IMS service, with this service - etc - it may be cheaper to sell??

Love the car and it runs strong (I am getting some clunking from what I think are rear trailing arms or droplinks).

Any thoughts would be appreciated!


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I have a durametric and checked my cam deviations when I first got it. It was somewhere in the -5.0 range. I then played with the program a few days later and my cam deviation changed to -4.0 range. I think it just changes based on when you check it. My deviation stayed solid throughout the rev range, so I’m not worried about it that much.

Good idea - I may try and remeasure it.


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You will only get accurate cam deviation values when the car is thoroughly warmed up, like after a 20-30 min drive.

Yep that’s what I’ve learned and I forgot to ask them if they did that before the measurement. Did you guys buy a Durametric wire so you can measure yourself without bringing to a Porsche shop?


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The Durametric is a good investment if you plan on doing your own maintenance. If you find that it’s no worthwhile to you, you can always resell it with a reasonable loss.

When cam deviations change over long periods of time, the most likely - although not only cause - can be wearing variocam chain pads. Replacement parts are inexpensive. The major cost is the labor time to remove the valve covers.

If your pads are wearing, the deviations will only get worse. If your numbers are accurate, you should determine the root cause given your on the edge of being out of spec. IMS in only one of many failure modes in 986 engines.

Sometimes you can identify wearing pads by finding brown chunks in the oil sump.