logray

Well P1341 is variocam solenoid/actuator or implausible sensor signal.

If you reset that code does it come back right away? That might confirm if it is a variocam solenoid or sensor.

If it does come back or not it might be worth logging your camshaft deviation and actual angles for bank 1 and 2 as well to confirm/deny that code.

If the car seems to run fine except at cold start for the first few minutes, that code might just be a side affect of the stumbling engine.

Still though man, you have a CPO warranty, so why worry? I would worry more about fidgeting with the car and having the dealer blame me and not covering it.

You wouldn't believe the crap I got away with with one of my CPOs on an old truck I had though... all depends on the dealer I guess.

seanmcr6

AS I said before...the dealer is 500Kms away from me. It's a HUGE hassle sending them the car. If I can determine the issue before hand and give them the heads up...they can give me back my car pretty quick.

Remember, it took them 5 trips and 6 months to fix my coolant leak issue. They are not the best at diagnosing issues.

In exactly 2 weeks I go on vacation for 2 weeks. So I'm planning to give them the car for that time so they can fix it. I would like to track down the issue or at least give them some direction before I do that.

I will record the camshaft deviation and actual angles at lunchtime.

Ahsai

What a mystery. Not sure what FRAU is. My understanidng is you will need to log 4 values:

Adaption, range 2 (FRA), bank 1 and 2
Adaption, range 1 (RKAT), bank 1 and 2

FRA corresponds to fuel trim at load (long term) and RKAT is for idle (short term). FRA should be close to 1 and RKAT should be close to 0.

seanmcr6

FML.....this is getting worst and worst.

Ok, so I have recordings on the FRA and RKAT. I'll get to those in a minute.

While I'm doing all this testing...I notice my oil pressure is sitting just below 2 during idle.

Now...the oil pressure sending unit was replaced last Aug...so I doubt it's off. When the dealer replaced my water pump last week, they gave me a jug of coolant and 2 quarts of oil. Which I found strange since they've never done that before. Plus, I understand the coolant, but why were they giving me oil?

I checked the levels of both when I picked up the car...and the next day...and 4 days later. (2 days ago) all were good. Coolant was down slightly, but well within range. If you watch the ids I've posted about the stumble recently, you'll see the oil level is full. I also checked this manually the last time, and the oil was right at the mid way on the dip stick.

When I rev the engine, the oil pressure shoots up, almost on par with the rpms, just with a slight delay. Usually...the pressure is above 3 at idle..and raises as I get the engine going. It stays up around 4/5 while driving above 3K. I've never seen it below 2.

I check my oil level by computer...it's half way?!@ Check it manually and sure enough the oil is way down at the bottom tip. WTF?! Where did my oil go? I'm talking about two days. To work and back twice. That's it. No puddle under my car.

man alive this car is driving me bananas.

Adaption Range 2 FRA Bank 1 remains at 1.01 consistently.
Adaption Range 2 FRA Bank 2 remains at 0.97 consistently.

Adaption Range 1 RKAT Bank 1 remains at 0.66 consistently.
Adaption Range 1 RKAT Bank 2 remains at 1.55 consistently.

Adaption Range 2 Lower FRAU Bank 1 remains at 1.01 consistently.
Adaption Range 3 Upper FRAO Bank 1 remains at 0.98 consistently.

Adaption Range 1 is the only one that seems to have a deviation between bank 1 and 2. However, I have no idea if it's supposed to be there or not.

CAMS


MAF

Macster

The symptoms do not point to the AOS. The AOS failing is a common failure and both banks' fuel trims would reflect the AOS failing.

The error code and the description of the symptoms matches what I experienced when my 02 Boxster's passenger side VarioCam solenoid (and actuator) went out.

At idle the engine ran horribly. But above idle it smoothed out and up to about 4K rpms (as high as I dared rev the engine) it ran just fine.

I cleared the error code and drove some distance (over 30 miles) with no symptoms and no error code. Obviously the solenoid/actuator failures were intermittent.

But I took the car in and the tech confirmed the solenoid was bad. The actuator proved to be bad too.

You have or the tech has to be careful. The PST2/PIWIS will almost certainly help him identify the solenoid is bad. But oftentimes, so the techs I rely upon tell me, is that the actuator will prove to be bad too. Often enough they advice the customer ok both items to be replaced.

Now what I think happens is the solenoid starts to go goofy and in doing so causes the actuator to be activated and deactivated and from this over time the actuator gets worn out. The trouble is that with the solenoid bad one can't id the bad actuator until the engine is buttoned up.

This is what happened in my case. For some reason even though I was told afterwards the SOP is to replace both the solenoid and actuator for some reason I was not given this option/choice. I was told the solenoid was bad and of course I agreed to its replacement. But once I had the car back the error code and symptoms returned after less than 50 miles of driving.

Back in the shop the actuator was id'd as being bad. But because I was not given the option of having both the solenoid and the actuator replaced (which I would have done based on the advice of the techs) I was only charged for the parts/labor specific to the actuator R&R. The extra labor came to about 4 hours (to get to the actuator the cams have to be removed and reinstalled and retimed) and the actuator of course has to be replaced once the cams are out of the way. The camshaft cover bolts of course have to be replaced and the camshaft cover resealed but I was not charged again for these parts, the sealer, or the labor.

Anyhow, in the case of the Boxster the engine stayed in the car but the exhaust pipe on the passenger side along with the camshaft cover had to come off. The cams had to be removed to gain access to the actuator.

All camshaft cover bolts had to be replaced: They come with a thread sealant and are not supposed to be reused. Some of these bolts fit on either side of the bearings that receive high pressure oil and the odds are the bolts will leak if they are reused. Sure the camshaft cover receives a proper application of sealer to prevent high pressure oil from leaving the bearing area but the bolt thread sealant is another barrier to the oil should this sealant not contain the oil from around the bearings. Besides the underneath side of the camshaft cover is subjected an oil storm while the engine is running. The oil pump can pump 60 or more liters of oil per minute at higher engine speeds and a good percentage of this oil is directed to the valve gear which resides directly udner the camshaft cover. All of this oil ultimately is sprayed, slung, splashed about under the cover before it is removed by the scavage pump.

The solenoid cost around $700 and the actuator around $800 but I received a discount (a bit more than 10% IIRC) due to my PCA membership and my good relationship with my dealer and its service department.

Oh, labor... the labor cost over $1000 and with incidentals (oil/filter service) and a problem with a broken exhaust pipe bolt the total cost of the repair came to around $3000 parts and labor, taxes and so on.

Sincerely,

Macster.

Ahsai

The FRA's and RKAT's all look excellent to me (0.66 and 1.55 are actaully 0.66% and 1.55% if I'm not mistaken, which means really good). And yes, they are supposed to flutuate. I do NOT know what FRAU and FRAO are though.

Re your oil, engine fully warmed up the oil pressure can get a tad below 2 BAR (assuming 0w-40 or 5w-40). If you checked the oil right after you stop the engine (especially a not fully warmed up engine) and don't let enought time for all the oil to return to the oil pan, it could read low. Just try to measure it again 10 - 15 minutes later.

logray

There is a VERY specific procedure in the work shop manual on how and where to apply the beads of sealant to the cam cover. Also, a very thin bead (according to the specification) goes a long way. You don't want excess sealant swimming around in your engine clogging tiny oil passageways.

Even this might be too much, even though it follows the Porsche specification/requirement.

logray

There are a lot of threads about where to run your oil level. Full to the brim is usually not recommended. Just over half-way is. There are also TSBs about overfilling and oil level, if your car is a 2002 model year it might require a new dipstick and/or oil level sensor along with instrument cluster re-programming (less oil).

Also agree that your oil pressure numbers sound consistent. Perhaps you're used to seeing higher oil pressures in colder temperatures and due to the warmer temperatures and selected oil viscosity you are seeing different oil pressures.

The cam readings look normal and it didn't look like one of the actual angles was different from the other, which should be consistent with functional cam mechanisms. Although, did you rev the engine a couple times or was that just from the stumbling startup? Also did the DTC come back after you cleared it?

It would be good to see the same graph at idle, then 5 seconds at 1500 rpm, and then 5 seconds at 3000 rpm all in a line.

Also would be good to see the camshaft deviation, in addition to the actual angle, I'm not sure that we need to see speculative angle.

seanmcr6

No, the DTC did not come back after I reset it.

My car is a 2004.

Yes, those spikes are me revving the engine.

So the FRA/RKAT are excellent...the MAF is bang on....the cams look good....and my oil pressure is fine.

Great. So I'm no further ahead I guess...hopefully the dealer can figure this **** out, cause I'm done. Nothing more I think I can do.

Thanks for all the suggestions and feedback everyone, It's greatly appreciated!!!

sean

Ahsai

The only suspicious thing I saw is your bank 1 cam reading. It has lots of "hash" and appears much noisier than bank 2.

logray

Good call out, I didn't notice that on first glance!

alexmtl

Sean, any update on this? My 996 TT has the exact same problem and it's driving me nuts!! So far I've changed the ignition coils, the spark plugs, the MAF sensor, the fuel filter and the air filter but the problem persists. I also inspected the cam sensor brackets to see if they are broken but both are in good shape. Hopefully the durametric tool I ordered today will help to shed some light on this. I'll let you know if I find anything.

Macster

You've eliminated quite a bit.

Hopefully with the Durametric tool you can verify the coolant and air temp sensors are providing reasonable readings, that one or both are not supplying a too low or too high a temperature which causes the DME to supply an air fuel mixture that is wrong for the actual coolant (engine) and air temperatures.

Also, if the temp sensors appear to be supplying reasonable values then hopefully you can verify the variable valve timing and lift is working properly. I can't think off hand what else could be the cause of your Turbo's symptoms.

Sincerely,

Macster.

seanmcr6

I checked my temp sensors and they were giving normal readings that didn't fluctuate.

I'm down to the air/fuel ratio.

Bottom line is the car is running way too rich on cold starts. Period. There is a very pronounced gas smell. only on cold start, never on warm ones. Once the system loop closes, it idles just fine.

I'm not sure what else I can do to pin point the exact cause, but I'm still pointing at the secondary air injector. It only runs on cold starts (during open loop)....so either there is a leak with that system or it's just pooched.

The only other thing I've found wrong(?) is the "actual angle for intake cam" on bank 1 shows much more deviation (in frequency, not amplitude) over bank 2. This is the same intake cam bank that threw a CEL too.

I leave for vacation next week. This weekend it gets dropped off at the dealer, with all the printouts and video recordings and hopefully they can find the root cause.

If their computer/diagnosis finds nothing, I'm asking them to check the SAI and the variocam mechanism (in it's entirety including the solenoid).

Seeing as I've eliminated most of the usual suspects, I'm hoping they can find the issue rather quickly.

If they find the issue within the first week, while I'm in Ottawa, I'll update this thread. If not, I'm in Cuba after that, with no internet access, so updates will wait until I get back.

Sean

alexmtl

I was able to read the temp between the two sensors with a cheap OBDII reader and the difference was 2-3 deg. Is that enough to cause this issue?

Also, my car runs smooth as glass once it's warmed up so if it was a defective variable valve timing would it only affect the engine when it's cold?