Rough running on recent rebuild - P1324

I am working out some issues on my recent rebuild of a 3.4 engine. You may have seen my thread from last week where I had low oil pressure which has now been corrected. Porschetech3 and others suggested that I could have a collapsed oil filter so this week I replace the oil filter and that problem has been resolved. Now I am having another strange issue. When I start the car the idle is smooth and it runs smoothly up to approx. 3,000 rpms, I am not taking it higher that that until I get a few hundred miles on the engine. However, after driving a few miles, and it may be when it reaches temperature it starts to miss some and run roughly. this seems to come and go for a short time and then become consistent, The first time this happened I parked the car overnight. And the next morning when I started the car the missing was gone and it idled and ran smoothly. But when I put my Durametric on it, it showed an error code of P1324, Porsche faut code 325 - Camshaft position with respect to crankshaft bank 2 below limit value. But there was no Check Engine Light on. As it was running smoothly I cleared the code and then looked at the actual values and there were no misfires and the cam advance, etc. seemed to be far under the 6 degrees. Then yesterday I went for another short drive and everything was smooth for a few miles and then it began to run roughly, the came and went for a few files and then it became consistent again. I parked it overnight and started it this morning and again it was smoothly but was showing the P1324 error code. Again I ran the Durametric for actual values and there were no misfires or other signs or problems So it is strange that the roughness goes away overnight with nothing being done. Any insights would be appreciated.

https://www.engine-codes.com/p1324.html

Unless I am misinterpreting, your camshaft deviation numbers are -12.5 and -22.3 degrees? Seems like that would be your problem, timing is way way off.

Variocam solenoid issue? Do the deviations change when you get over 1500 rpm (or whenever it kicks on)?

Code 1324 means your camshaft advance/retard ( variocam) is not following the commands of the DME on bank 2 ...It is slow to react or slow to return to rest position.. Warm up the car and hook-up Durametric and set to "log" the camshaft values you have there on the screen during a road test ..( BTW I can't make out the details of the screenshots).. Then come back and review the LOG .. what you are looking for is if the bank 2 specs are slow to rise, or slow to return to rest as compared to bank 1 ( the command from the DME)... If bank 2 is slow to respond/return, the problem is the actuator its' self.. .A problem in the solenoid or DME will be a no function of the variocam at all,

Just so everyone knows the actual values read outs the screen shot are as follows: Camshaft position 1 deviation --12.52 Camshaft position 2 deviation -22.31 Actual angle for camshaft bank 1 -1.66 Actual angle for camshaft bank 2 -.063 I set the camshaft timing with the tool that adjusts the camshaft after the crankshaft is lock a at TDC with the rotation between setting each bank camshaft and it is hard to believe that it could be off by 12 to 22 degrees with the tool. The was done before the engine was fully assembled and installed. All the guides and pads were replaced as part of the rebuild. I am not sure what the camshaft deviation for each position means, I have also concentrated on the Actual angles are as this is where the 6 degree limit is I believe. I hope it is not an actuator itself and it needs to be replaced as the cams have to come out to do that and that is a pain to do with the engine in the car. I an going to go warm the car up and log the values now.

Yes, it's hard to believe you are off by 12* and 22* using the tool.. The actuators are bank specific, is it possible you have the bank 1 on the bank 2 side and vice versa? Do you have any pics of the rebuild? Sounds like to me you have the actuators swapped..

Here is a log of a run I took this afternoon. Sorry there are so many pages. you can see that the Camshaft Position deviations stay very consistent. The actual angles vary but seem to follow along fairly closely although same lags in advancing and dropping. Also it seems that maybe to position sensor may be lagging as the angle will go from 25 to .5 and back to 25 (approx) in a second. And sometimes the differences will be over 6 degrees for a second or two. It is hard for me to imagine that I exchanged the actuators.as I was changing the pads etc. and they actually work in reverse as they advance the cams relative to the crankshaft so they push the top of the change on one side and the bottom of the chain on the other side to advance the cams. The P1324 code did come back on during this drive but I actually took a few drives, I did not record all of them as I was learning how to do the logging. But in the 15-20 minutes f driving the engine continued to run smoothly and never missed.

So if I exchanged the actuators wouldn't they be retarding the cams rather than advancing them.

Well, your actuators are synchronized very well, they work at the same time all the way through the LOG... One thing to note:: the timing tool sets the exhaust cams only...( but the sensor is on the intake cam). The intake cam is set by counting links on the chain...and I think one link is about 12*.. So if bank 1 is off 1 link and bank 2 is of by 2 links, that could be why the deviation is 12* and 22*.... So even though you used the tool correctly to set the exhaust cam,,, the actual sensor is reading the intake cam which could be off by the link count.. You can pop the uppe cam plug out and see the timing tab for the sensor.. at TDC it should be pointing at about 3:30 o'clock...there are some pictures in the archive of a correctly timed and link count of the intake cam..

I started working on engines as a kid, helping my brother rebuild a MGA including the en engine in the late ‘60s and an Alfa Romeo that I bought in the early ‘70s then I owned 5 Porsche before this on from the 78s onward including air cooled 911s and two 928’s but never did major engine work on any of the. I bought this 996 in August of 2000. In the fall of 2008 I had an intermix and dropped the engine is spring of 2009 I dropped the engine to find the problem (back the pretty much everyone, including Flat Six said I needed a new engine but I could not afford one right then. ironically I started with the 1-3 head, removing the cams, etc. using some homemade tools. Once I had the cams, actuator’s, lifters and lifter tray I found the crack in the cylinder 3 inner exhaust valve seat and found a shop in Costa Mesa that fixed the head for me. So I was dealing with the head, chains, actuator, cams etc. starting then And on the first start up one of the plugs int the end of the intake cam blew out and there was oil spewing everywhere. It turned out that the hold down tool I had made deformed the plug and I had all four cams drilled, threaded and put in threaded plugs rather than pressure fitted plugs ( this is one of the known failure modes that Flat Six lists and threading the cams is now a standard upgrade. All this is just to say that I have had the cams, actuators, chains, etc. in and out several time before this rebuild and I always managed to count the links and get the actuators back in the proper side. But that is not to say this could not have happened, I am not perfect. I can certainly take out the green plugs and even the scavenger pumps to try to get a good look at the links, cam slots, etc. but it might be necessary to take off the cam covers off the get a good count on the links, etc, and at that point also look at the part numbers on the actuators. I have one actuator in my basement and once had one that was new and I bought on eBay cheap but sold to another Rennlist member years ago when he needed one. And the damn things have gotten really expensive. I also have found that if you need to remove cams, etc. it is easier to drop the engine, I can do this in 4-5 hours on stands in my driveway as in 2009 I had to remove the cams a few times. So I am familiar with the process. But it is hard for me to believe that I got one side off by one link and the other by two links and that it would run as smoothly as it does if they are off by that much. I should say that I haven’t had it over 3,500 rpm yet.But I guess I can pop a few green plugs to start. Darn it! It is running smoothly and was pulling strongly today though. Thanks for your ideas, thought and comments!

I think I have a couple actuators I could sell you cheap if you still need some.

Situation is suspicious. Sustained cam deviation like this should render the car close to undriveable, and you should have multiple codes for both bank 1 and 2, as well as a CEL (cam deviation threshold for a CEL is around 9). You should have massive power loss and it does not sound like this is the case. Would consider swapping the cam position sensors and perhaps the actuator solenoids before dropping the engine. Maybe hard reset the DME also.

Quotes source post: 19023611

You know I just fixing to suggest this....lol I had one once that had code 1324, that I re-timed several times, replaced cam sensors, actuators everything and it was still there, and just for ****s and giggles I did a hard re-set and it fixed it.... Also you would be surprised how well the engine will run with just the intake cam off by 20* I had an Over Head Cam engine in Drag Car back in the70's 80' with an external adjustable cam gear.. I had a bunch of cams and would move the cam plus or minus as much as 10* just trying to set a new ET record, sometimes it would lose a little sometimes gain a little...mostly just moves the powerband around......lol

What is a hard reset of the DME and how is this done?

Quotes source post: 19023768

Disconnect the positive and negative battery cables, wait a couple minutes, then touch them together... Then re-attach them.. You will have to go back through and re-learn/reset all the pre-sets/memories, for radio, seats, mirrors, sunroof, windows, DME, clock, ect....

I just did the hard reset but i am not sure this will solve the problem I am going to run the Durometric and a log. I gues the next step will be to remove the cam covers and count the links between the sprockets. Every other time I I have worked on the cams, etc. I have dropped the engine as I can do this in about 4-5 hours and it is really tight doing this with the engine in the car. And of course you have to take off the exhaust, rear bumper and misc other things to do it with the engine in the car. But what the heck I will try to take a look and if I can count the links and they are off I will decide whether to drop the engine. All this is kind of frustrating as the engine is running so smoothly even with this discrepancy. And you don't want to see the look on my wife's face when I start this work.

Well, I got a little excited but for naught. After doing the hard resent and starting the Durometric and looking at the actual values the camshaft position 1 deviation and the camshaft position 2 values were both reding 0! But the Actual angles were reading much higher than about 0. more like the 12 and 22. That used to show for the camshaft positions. But after a minute or so the camshaft position 1 and 2 deviations went back to the 12 and 22 and the actual angles dropped. So for a short time I was thinking that the hard reset had shown that the camshaft positions were ok but it looks like the cam covers have to come off! Darn!!

Quotes source post: 19026286

Dang. Does that make sense for it to be running well with those kinds of numbers?

Made some good progress in dropping the engine this weekend. After taking off the rear bumper, mufflers and more I say that getting at the cam covers was going to be a nightmare, particularly with the muffler brackets in place and getting at the upper bolts for these is just about impossible. And then getting the cams, chains and actuator out, rest and then back in and the sealant in the cam covers? Now I remember why I always dropped the engine in the past. I also now remember how on a 24-year-old car that has gone through 23 Chicago winters just how corroded many bolts, etc. are and how long many of them take to get off which makes the removal take much longer than it should. Some nuts and bolts take 15 minutes or so when the should take 1-2 minutes. And about 12:00 just as I was putting the transmission jack and the Motorcycle lift under the engine, I got some vertigo and had to stop for the day. I have had this before when I was laying under the car for long periods of time and it sometimes takes a day or two to clear up. Too bad because once the engine is out from under the car, I can just sit next to it to do the cams. Hoping to have the time this week to finish it up.

What happened with this thread ? .. i was reading along with great anticipation of route cause . then nothing ..

Quotes source post: 19662378

Yea, I hate it when that happens.....I hope Dharn55 is OK...