Zakowsky

So I have posted a lot about repairing my 2004 CCT over the years, but it has been running great for the past while; full steady boost, smooth idle etc. But I am worried that after 350,000 kms this might be it. Over the years I have got P0018 - 08: Retard Setpoint not Reached (Over-Advanced) - Intermittent, but this always goes away if I change the oil (or top it up if it is low) and it never affected drivability. But I was driving today at higher rpm, and when I dropped down to idle it nearly died, stumbling and could barely take throttle. When I got it back to about 3K rpm it ran fine. Was an interesting version of the movie "Speed" driving home...

Now I have P0018 Crankshaft position in relation to bank 2 intake camshaft (Above upper limit value) with my PIWIS, and it misfires and stumbles at idle. So the obvious order here I believe is:
1) Cam position sensor
2) Camshaft adjustment actuator
3) Camshaft adjuster
4) Timing chain
5) Spun camshaft bearing

Now I don't think it is the sensors, because they both give data, Bank 2 obviously not looking right. I unplugged the actuators and there was no change at idle like some people report, it still ran like crap. So I am thinking it must be the adjusters or worse. So I am wondering:

How do the actuators work - I thought they kick in at higher rpms, so at idle it should be not too bad (and it is). Or could one have got stuck in whatever position they are in at 3K rpm and that is why it is not right at idle? There is a "not normal" sound coming from the front of the bank 2 rocker cover.

The engine has a lot of miles on it so before I buy the sensor, then actuator, then the adjust etc. I was wondering if anyone has any ideas or experience with this. I was thinking of putting a can of SeaFoam in and changing the oil first incase the stuck actuator theory makes any sense. Thanks, and here are the details.

P0018 Crankshaft position in relation to bank 2 intake camshaft(Above upper limit value)
Fault: 4012
Fault status: Active
Fault path number: 149
Fault duration (current cycle): 255
Fault path status: 131
Fault type: 17
Entry status: 132
Fault class: 3
Check Engine on: 1
Check Engine off: 4
Clear counter: 20
Control status, bank 1: 2
Control status, bank 2: 2
Relative air mass: 2.7 %
Engine temperature: 78 °C
Control factor, bank 1: 1.00
Adaption factor, bank 1: 0.99
Control factor, bank 2: 0.77
Adaption factor, bank 2: 0.99
Manifold pres.: 255
Rpm: 1320 1/min
Vehicle speed: 0 km/h
System time, occurrence of 1st fault: 3483
Mileage, 1st occurrence: 53732
First state: Deviation of the adaptation angle from the vehicle-specific setpoint angle of camshaft: 2 12.00 °crk
First state: Camshaft adap. angle [retar. limit]: 108.00 °crk
System time, occurrence of last fault: 65535
Mileage, last occurrence: 65535
Last state: Deviation of the adaptation angle from the vehicle-specific setpoint angle of camshaft 2: 1020.00 °crk
Last state: Camshaft adap. angle [retar. limit]: 510.00 °crk
Frequency: 1

Petza914

I would pull the spark plugs from the bank that's making the noise. If any of them look different than the others and different from one you pull from the other bank, that could be a clue. If the noise bank has oil fouled plugs, combined with your climate, and the mileage on the engine, that could be scored cylinders. While the plugs are our look in the bores to see if you see anything like a lot of oil on top of one piston or any score lines.

Zakowsky

Thanks Pete,

Yeah, I have long wondered why I don’t seem to have scored cylinders, given the mileage and the cold up here, given all the threads about it. But I checked the cylinders with a Boroscope not too long ago and they were fine; not perfect but ok. Doesn’t mean a problem didn’t start and I will check them.

But it is really weird if you look at the VAL data from the PIWIS. The Last state deviation is 1020 degrees, and the adaptation angle is 510 degrees. That’s wrong, any way you look at it I think. Maybe I am wrong assuming it is not just the sensor. PITA to swap sides and it is the cheapest part, so maybe I should just replace it and see what happens.

Coincidentally the 997 started making noise from the serpentine belt area the very same day, hopefully an idler pulley and not the water pump. But I wound up driving the kids in in the 944. Handy to be a 3 Porsche family (or 6 as in your case!).

Petza914

Ha Ha, that's right.

I hope the Cayenne is OK and it's just a sensor or solenoid. Does seem odd to survive that many miles up there and now develop a problem.

On the 997, check the tensioner and it's pulley too. Look specifically at the water pump weep hole for any dried coolant. That's where it starts.

J'sWorld

Look at the actual values of the cams while its running.

Zakowsky

That is the plan for the weekend. There has to be some logic to it running ok above 3,000 rpm.

I checked the 3 small pulleys - the easy to get to one (#8 I think) spun fast and loud, so I thought it was that (the other two were fine). I repacked the bearing to test this but no change. I have zero leaks from the wp and the bearing has no play, but when you spin it it sounds like there is no water inside. So now I am worried I have air in the system and what I am hearing is cavitation. I read in a post here on this that you can run the engine with no Y-pipe on, is that true? That would help diagnostics. But I should start a thread about this in the other forum.

Got to get one of them on the road!

Zakowsky

OK, some data. For all its problems, it does amaze me that the engine still runs enough to get this. It is a bit hard to read; the vertical axis has zero at the middle for all except the green trace (which is the actual position of intake camshaft bank 2, about 40 degrees), and the blue trace (camshaft 2 deviation) is stuck right on zero, right along the top of the red trace (actual position of intake camshaft bank 1). The deviation for cam B1 (black) is around -4 degrees.



So this is a thinker. The engine runs like the intake cam on bank 2 really is 40 degrees off (backfires, stumbles and you can hear things you don't normally hear through the exhaust), but the readings the sensor are getting are pretty shaky - or the cam is in fact pretty shaky running this far off. But why is the deviation of this cam zero? That sounds like misinformation, and maybe the sensor is feeding wrong data to the ECU, causing the cam to shift to 40 degrees off. Bank 1 seems fine, and while 4 degrees off is a lot, it is still OK for an old engine.

Now new error codes are here - sorry for the screen shot but the PIWIS is a PITA sometimes to log and save with.

So the P0018 makes sense, if the cam is 40 degree off where it should be. But the Intake camshaft adjuster final stage errors that say there is no communication with them which is odd, in that both banks are reporting an error but bank 1 seems fine.

So if the choices are sensor, actuator or adjuster, which is the best guess? Important call, because if it is clearly the adjusters, then it's probably not worth the work and cost for this old an engine. Does the data now suggest it might be a wiring harness problem as well? Any opinions would be appreciated, thanks.

Petza914

On my 997, the only time I've seen a camshaft deviation of 0.0000 is when the cam position sensor failed. A replacement fixed the issue. If you've replaced that sensor, then it could be the wiring going to that sensor (corrosion, rodent chewing, insulation degradation, etc)




​​​​​​When the car is cold and you first start it, does it run fine for about a minute then start stumbling?

Zakowsky

Excellent Pete, thanks! That is a great clue, and exactly what my camshaft deviations look like. Cold or warm it instantly starts running badly, and this morning I checked the wiring and everything seems fine. And it might even be possible to get the Bank 2 sensor out without taking the intake manifold off by the look of it. I am going to order a new sensor from FCP tonight (and a new water pump for the 997...) and should get it by the end of next week I hope.

bigbuzuki

You can change the bank 2 sensor without manifold removal.
Suggest removing the SAI pump as it will assist access.

Zakowsky

I looked at it closer today and yes, should be doable - I know that corner of the engine well after doing my coolant T's! I ordered valve cover gaskets as well, so I think if the sensor is the problem I will finally fix those as well.

rileyracing1

And .... everyone worries about bore scoring ?? 350k on it in Calgary even..good on you ..I hope my 05 Cayenne S goes that long without giving up the ghost .

Zakowsky

Yeah, I don't know if I am just lucky with this one or what. I take care of the engine but not obsessively; it goes too long between oil changes sometimes, I run it low on oil sometimes. And when I got a 911 I must admit the 911 took the CTT's spot in the garage, so it has spent two winters now in the driveway. It sat overnight in -35 degrees Celsius temps a few times, and it complained a bit but started fine in the morning. But I have seen some 955's in Kijiji that are selling for like $4000 that say they have bore scoring, so Alberta is not without the problem. I think it is driving it hard but not too hard each day that keeps it going.

My new sensor is on the truck for delivery today so hopefully I will know if that was it this weekend.

Zakowsky

Fail. The new sensor made no difference, still reporting the same, which I guess is accurate. It idles like the intake is 40 degree off. So I guess the next step is the actuator – the resistance is exactly the same as the good Bank, so maybe it is stuck? Has anyone cleaned one of these up and got it to work again? Would rather not wait another week to find it is not that, and actually the adjuster. Thanks.

Andrew_955

Most vvt systems have a locking pin in the pulley which is used to hold the cam during start up while oil pressure is low, these can become sticky on some engines.
There will also likely be a small gauze type oil filter at the solenoid which can clog on some engines and cause vvt issues too.