coleta

Thanks and Congratulations

harperb, what did you originally bring your car in for? What were the symptoms?

Great info. Thanks again JFP.

Thanks JFP. Great links. snorth54 post seems to support my above claim that deviation never changes because it's a value that is only calculated during cranking, because it's a reflection of base mechanical timing.

He recorded:

The camshaft position 1 deviation is always 1.28 regardless of RPM

The camshaft position 2 deviation is always -0-09 regardless of RPM

Actual angle is totally different and does change dynamically because it displays, not the mechanical base timing, but the actual movement of the variocam mechanism.

He notes:

At 3522 RPM the Spec angle for inlet camshaft bank 1 is -40 and the Spec angle for camshaft bank 2 is -40

At 3522 RPM the Actual angle for inlet camshaft bank 1 is -39.65 and the Spec angle for camshaft bank 2 is -40.12

The deviation and actual values should mean the same thing regardless of whether it's variocam or variocam plus. The only differece would be in the actual values themselves, @25 max for the former and @ 40 for the latter.

Based on your experience, does this make sense (as this is all theoretical)?

Thanks again

JFP,

This is true. But it seems the value that is read while the car is running is a value that the DME calculated during cranking. So if the relationship of the cams to crank changed while the car was running and the car has not been turned off and re-cranked the deviation value will not change. The car would have to be re-started so that during cranking the DME can recheck this calculation and then display the new value while running.

I know many cars that work like this, but I don't know if this is the case with Porsche.

If you or anybody else has actually seen the deviation values change while the car is running, then this will prove that Porsche's system is different than most out there.

JFP, I was under the impression that the deviation values was calculated at cranking and was not "live" data. So if the IMS went, the only way to see a change would be to note the deviation, turn the car off and then on again and recheck to see if it changed.

Is this right? If it's not, have you ever seen deviation values change while the car is running?

Thanks again.

Smart dgcook. Ditto on the pics.

JFP,

Which variocam readings are you refering to, the actual angle or the deviation?

Thanks

Thanks. Great info guys.

mudman2,

Could you give some specific examples of what you've seen with this fault and under what conditions they went away?

Thanks

Does this happen regardless of tire brand? Any one have an explanation as to why this happens?

Awesome stuff. Thanks

RFM,

Could you share with us:

1. what normal HC,CO,CO2,O2 reading are?

2. are they checked before or after the cats?

3. under what conditions? at idle? 3000 rpm? or is it while driving under load?

4. what readings with HC, CO,CO2,O2 indicate bad cats?

And thanks for the temp difference info.

Great news. Do you know how they were able to isolate it to the cat.?

otisdriftwood,

Could you read out the oxygen sensing,tra, and fra values with your tester before replacing the aos? I just want it for reference.

Thanks

Thanks RFM. Your point being that the stretch in the chain can be compensated for with NO parts replaced, only a re-timing because the stretch is minor. Right?

RFM:

You've posted several times this can be fixed by retiming. Have you had the chance to note the before and after actual values on the cam deviations?

Thanks

No one's ever noted this, huh?

Has anybody ever noted the tra/rkat and fra values when an AOS went BEFORE replacement. Can you all post them here?

Hi Loren,

Some tsbs only load the first page. I tried to look at Cayenne tsb 22/07 4438 on troubleshooting the tire monitor system. I can only view the first page of thirteen. I tried multiple times and at different times during the day, both downloading directly to laptop or simply opening it up straight from site and it's always the same thing.

Should I just keep trying or is this all we can get?

Thanks

Cloudsurfer,

What ever became of this?

RFM,

If the sensor has no contact with the coolant how does it know what the level is?

Loren,

Is there anything in actual values or elsewhere that would give a clue that there's an issue with the MAF in a case like this or do you just have to roll the dice after replacing a brake switch?

Thanks

That's why I was recking my brain, thanks. One more dumb question: how do you PM?

Loren,

I found this post you made a few years ago:

More than two meanings for the temp light...

Covers all Carrera (996), GT3, TT / GT2 and Boxster (986) cars

Here is the long explanation from the service manual on the flashing coolant light.

"Four functions of the coolant warning light:

1. Engine coolant level too low -- light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high -- light is lit; pointer on the right

4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

Can you give the exact reference for this? I've looked in the workshop and owners manuals and can't find it anywhere. It's driving me crazy.

Thanks