swede man

Zero cam deviation.
Just wondering if anyone knows how it's possible to have zero camshaft deviation on my 99 C2 with 150K on the clock? Thanks

Schnell Gelb

a few more details please - so we can help better.
Is this an ROW engine ?
What are the Actual Values on both Banks at 3000 rpm with a warm engine ?
What happens when you Activate the Cam advance with Durametric at idle with a warm engine on each Bank?
Do you have any related Codes or Pending Codes ?
New pads on the Variocam Actuator recently?

mayday1

I have exactly the same problem with my 99 C2. Right after I bought the car last year I took it to
an indy shop to check it out, and the CAM deviation was 0 on both banks. They didn't know why
it was, and suspected the ECU was cleaned/reset before I bought it, although it showed a small number of
overrev a few hours before I bought it. I was told to just drive it for a month and came back for a recheck. CAM deviation was still zero the 2nd time they checked.

My 99 C2 has a dealer installed remanufactured engine in 2005, may be that confused the ECU?

Schnell Gelb

If the zero deviation guys are concerned about Variocam pad wear being concealed by a fake reading - inspect the oil filter element and pan for pad debris?
Pop the green plugs and do a basic static valve timing inspection also.Cheap and easy.BTW you can repair the green plugs if you are careful and they will work long enough for replacements to arrive.

gdotcvg

New to this forum. I have a 1998 986 and am also seeing zero deviation on both banks. Car is running great, zero debris in filter. Just curious why this may be.

Flat6 Innovations

This happens with 99s all the time... A zero reading means the sensor or DME are not reading.

Schnell Gelb

There seems to be only one guy who can answer such questions & it clearly is not anyone but .....:-).
The Noid test, the click test and the MOM switch/click Test to confirm this are all in my Renntech/Boxster Thread .They are all variations of a test I first read on RennTech by Ahsai.
If both banks show zero Deviation , I guess this points toward a DME fault because that component is common to both banks.
Some ROW (?) cars have only 1 Cam Position Sensor. Others(USA) have one on each bank.So that confuses things.
See Fig 5 in the link for USA cars.
http://www.pelicanparts.com/techarti...ne_Sensors.htm
So for USA cars ,if both Cam Sensors were defective - it would produce zero Deviation on both Banks.An ROW car with only 1 Camshaft Position Sensor sensor would be more confusing .
Durametric would also show in Actual Values , no response to prompting Variocam Advance.Also there would be(?) no Variocam advance above 3000 rpm with a warm engine.
The reason is because the Cam Sensor could not read or the DME failed to activate the Variocam Solenoid. I think . But check with someone smarter at this than me.

swede man

Thank you Jake and Schnell for chiming in on this, I know that Asaih has a very good understanding in regards how this system operates and hopefully he might be able to share some knowledge on this.
As Schnell suggested I allready checked the static valve timing which is as far I can see spot on, I have also dropped the sump plate and everything in there is clean without any debris,I change oil and filter every 3K, the car still drives amazing especially after I had my injectors cleaned a few weeks ago. There was no particular reason for checking out the cam deviation but I had the day of yesterday and was just playing around with my Durametric (:

Schnell Gelb

So what happens when you used your Durametric to Activate the valve timing advance? You should hear the engine go slightly lumpy if it is idling.
I am trying to separate and test 2 different functions for you:
1. Deviation
2. Advance.
The results may narrow down the component failure suspects.

swede man

The engine starts running very lumpy when I activate the valve timing advance with Durametric, there is still no change in deviation while doing this. My engine has the ROW specs in case that matters?

Schnell Gelb

Yes it does ,see Post 2 above.
Do you have a Code for a malfuntioning Camshaft Position sensor? You only have one !
Obviously the Cam advance is working.

swede man

OK thanks Schnell, I have just checked again with Durametric and there are no fault codes present nor is the CEL coming on. (CEL light is working)
As mentioned earlier, the car drives absolutely fine but I'm puzzled by the fact that I get a zero deviation reading on an engine that has traveled 150K, surely this can't be true?

DBJoe996

Did anyone consider it might be the Durametric software? What version of Durametric are you running? And I know that several Durametric functions and readings are flaky on 99's. Maybe an Indy with PWIIS could check it to see what it reports.

Schnell Gelb

good point.If this is a clone we are wasting our time.
The only remaining action is to check the continuity to/from & resistance of the Cam Position Sensor .
After that we're back to Post 6

mayday1

My zero deviation reading was from an indy mechanic. I don't think he used durametric, he used a rugged laptop that seemed to be built for this. The shop only works on porsches (mostly air-cooled though) and nothing else.