2001 Boxster Camshaft issues - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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I just checked the codes and it is now showing the p1341 along with a cylinder 1 and 2 missfire code... at idle both bank 1 and 2 are showing actual camshaft values of .000 or .033 and they are both the same but it still has a lumpy idle....

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It may make sense to replace the Cam position sensor at this point. I hate to just replace parts trying to fix a problem but diagnosing a problem via the internet is um rather difficult. I don't think the Cam sensor is expensive, the code is referencing it so at this point I would change it out and see what happens. Poor lumpy idle can also indicate a major vacuum leak. Keep us posted.

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Lets see what your cam deviation shows after you change out the cam sensor. Then I will describe a way to use your Durametric to test your MAF sensor. Faulty MAF can cause lumpy idle. But I will tell you how to test it after we see if the new Cam sensor cures the problem.

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Sounds good, I will order a new camshaft position sensor right now, and I believe the bank 1 sensor is below the air oil separator so Ill use it as an opportunity to replace that since i experience smoky startups sometimes! thanks for the help, ill report back once i do the swap!

Good luck.

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Its quite odd, Even though I got the engines timing right when I first start the car in the morning it runs great. idles amazing, but right when the car warms up the lumpy idle begins. I checked the camshaft deviations at idle after a long drive and camshaft position 1 deviation was at 19.23 degrees and camshaft position 2 was at -6.25, meanwhile their actual angles was 1= .33 and 2= -.13. Given this information is it possible the variocam actuator and solenoid I was sold was a dud and its sticking when activated which explains the car idling great sometimes but like trash other times, and I assume the following missfire codes are the car adjusting fueling to compensate for the bad timing leading to a missfire. What i do know is when I hit the gas the car revs smooth and goes like a boxster should. I know in the future i was planning on replacing my 116,000 mile old ims bearing and also replacing the trans fluid in the tiptronic so maybe I should just drop this engine for an overhaul? I dont know what to do at this point ive alredy taken off the passenger camshaft cover off 4 times becuase the first time I used too much sealant and the plugs popped out, the 2nd time a bolt broke and i had to take everything apart to extract it, and now I am guessing the worst that my "new" camshaft actuator/solenoid are garbadge and I have to redo the whole project.

Start with the easy stuff first. Lumpy idle can very frequently be traced to the MAF. ESPECIALLY when, as you describe, it's fine when cold. But when the motor warms and it kicks out of the pre-programmed cold start settings and starts using sensors to determine settings then it gets rough..... yeah.... in my world that points to MAF all day long. AND it's easy to check. When your idle gets rough, unplug your MAF and see if it smooths back out. Always easy stuff first. Sent from my SM-G970U using Tapatalk

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Unplugging your MAF senor to check MAF sensor condition is not a very reliable test of the MAF sensor. Yes it seems to work if your sensor is bad. But by unplugging it your not really testing it. What if you have a vacuum leak? A vacuum leak can cause lumpy idle, it is a lean condition due to the unmetered air. When you unplug the MAF the DME reverts to a default fueling strategy based mostly on engine load and RPM. That default fueling strategy is biased on the rich side which tends to compensate for the lean condition so the car idles and runs rather well with a vacuum leak and the MAF unplugged. Plug the MAF back in or replace it now the car again idles lumpy because in this case it was a vacuum leak. So now in this case you have spent what? over $200.00 on a new MAF sensor and not fixed the lumpy idle. Much more reliable ways to test the MAF. Fuel trims and comparing Throttle Position Sensor signal to MAF sensor signal are two means.

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Odd situation. Have you replaced the Cam position sensor on bank 1 yet? When you replaced the Cam actuator/solenoid did you check to see if there were the proper number of chain links between timing marks on the Cams?

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+1 on checking the sensor. If the actuator was bad, that shouldn`t affect cam deviation much, only the actual cam angle. If you are in doubt regarding the actuator and solenoid, you can directly inspect them using a borescope. But it`s more likely that something is off with your sensor or timing.

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you're not wrong on any of that, Blue, but I feel like you're barking up a tree which doesn't get much attention because it's so uncommon. As you say; there are ABSOLUTELY more reliable ways to positively-test a MAF, but none as easy to narrow-down what's going on. Basic Troubleshooting 101 says see if you can produce a change in the symptoms . If unplugging the MAF produces a change in symptoms, then you are one step closer to understanding what's REALLY going on. We're chasing cam solenoids and timing, without (seemingly) to have checked some of the (honestly more likely) easy and cheap items. Vacuum leaks are VERY common, of course; but how many of them will show up only during closed-loop, or open-loop? Most of them will be causing the same issue regardless. Again; y'all can chase whichever squirrels you like, but the OP asked for some suggestions. I'm simply suggesting that the easiest and cheapest things shouldn't be overlooked in favor of something more complex, for no apparent reason. Especially when the more complex things have been checked and seem to be correct.

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There is a little dimple on each camshaft. I used white nail polish to mark the chain link to each dimple on the intake and exhaust camshaft so that when i cut the zip tie holding tension on each camshaft the tension pushed the cams apart but they were still in time. The dots lined up. I reassembled the engine then I did not install the oil scavenge pump, rather I put the camshaft not crankshaft in time, used the IMS camshaft locking tool to hold the bank one camshaft in top dead center timing, then i loosened the 4 bolts on the pullet on the side of the motor and turned the crankshaft to top dead center, inserted a dowel pin on the timing mark then tightened the 4 camshaft sprocket bolts. then i proceeded to reinstall the scavenge pump, removed the ims tool and completed the job. I believe that that is the proper way to time these engines as demonstrated in a thread i read on timing the m96. I have not had a chance to replace the camshaft position sensor, I am still waiting on the package I ordered a few days ago it should be in soon and ill put it in asap. I have previously cleaned my mass airflow sensor, I have not done anything other than a visual inspection for vacuum leaks. nothing is blatantly torn or ruined. Ill do a smoke test if the camshaft position sensor doesn't fix the issue. Im just wondering , if it was a vacuum leak why would the car specifically complain with a p1341 code rather than a generic missfire code. Later today Ill pull off the maf connector and report on what happens as well. and I forgot to mention, the car has no cracked ignition coils they visually look great and it has brand new spark plugs. and its fuel economy has been TRASH averaging 12.6 mpg thereabouts.

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So first: It is very hard to diagnose a problem via the internet. Second: It can be very hard to fix a problem that is diagnosed by well meaning people via the internet. Multiple people will have different points of view on the problem and how to fix it. As another poster has said simplest things first. Lumpy idle is an indication of a vacuum leak. So is stalling out when coming to a stop. You have both symptoms so I suggested the possibility of a vacuum leak. Simple and basic. But you also have the P1341 code which is a Cam position sensor or cam position related code. Bad Cam position sensor or bad Cam timing can also cause lumpy idle stalling at stops and poor fuel mileage So in another post I suggested checking the Cam position sensor and its related wiring. If I remember correctly you found issues with the cam actuator so you replaced it. But you still have Cam deviation issues. Bad Cam position sensor or wiring (simple and basic) or bad Cam timing (not so basic) are all I can think of as causes. The P1341 along with the Cam deviation issue is to me the most telling they are why I brought up Cam timing. But I would change out the Cam sensor first and see what happens. Simple and basic. So those are my reasons for my suggestions God I hope I made some sense here. LOL

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no you made perfect sense, and im extremely grateful for all the input. Ill do a visual inspection of all the wiring, along with the maf and vacuum leak test while I wait for my cam position sensor to come in. once it comes in ill report back on more findings. Sorry if I am being hard to explain to perhaps im a tad frustrated at my car haha.

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Maytag, I agree with some of what your saying. If you have ever read any of my previous posts I very often suggest that a person check and prove good or bad the simplest things first and work their way up the diagnostic ladder step by step from simplest to most complex. I first started trying to help Kbod in another thread that addressed the same issue he is describing in this thread. In both threads he has stated that he gets a reoccurring P1341 code. Bank 1 Lumpy idle after warmup and stalling at stops. He also has excessive Cam deviation on Bank 1 Vacuum leaks are very simple and basic and can cause lumpy idle and stalling. That is why I mentioned Vacuum leaks to Kbod. Many time they only cause lumpy idle and stalling after warmup. Why? Because on cold start open loop the DME is providing a very rich mixture with no feedback from the O2 sensors. Tends to compensate for the unmetered air from the vacuum leak, so the car may idle just fine.. Once the system warms up and goes into closed loop the mixture leans out and becomes too lean at idle because of the vacuum leak. So you may get lumpy idle warmed up but not on cold start. What I first suggested to Kbod was to check for any wiring issues related to the Cam position sensor on bank 1 Why? The P1341 code. Checking the wiring and testing the Cam position sensor would be my starting point. I don't know how to go about testing a Cam position sensor. So I suggested replacing it. Seemed the simplest, most basic most logical and cheapest to me. I mentioned Cam timing because Kbod had replaced the Actuator on bank 1. and still has the issue. Not sure how I am barking up the wrong tree.The P1341 code gives a good tree to bark up As for the MAF sensor and vacuum leaks, which either could cause the lumpy idle. I told Kbod I can tell him how to test both the MAF and possibly for vacuum leaks with his Durametric after we see what affect changing the Cam position sensor has. Although I don't think the MAF or vacuum leaks are the issue. Not sure what squirrels I am chasing. But I could be, very hard to diagnose an issue via the internet.

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To test out the camshaft position sensor he could just swap it with the other bank`s and see if the error code moves. As far as I can recall they are interchangable.

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Honestly., Blue, you're kinda my hero right now. I look at how much time you're spending trying to help and I think to myself "now there's a guy trying to get into Car-Heaven" or wherever car-saints go to. The amount of effort you've put in here is MUCH greater than my own "dive bomb" effort to spread too little too late. haha. I'll bow immediately to your logic and reasoning, 'cuz it's right on target, near as I can tell. And you're so right: diagnosing over the internet is iffy at best. Happy New Year!!

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Being old, single, retired, and a car nut I have time to try to help others. I have always had an interest in things mechanical. When the computer age came along it changed automobiles in many ways. The DME/ECU and the OBDI and OBDII systems came along and I was lost. What do you mean I can't adjust the timing Multiport fuel injection Check engine light???? P-Codes????WTF????? So I have had to try and learn what I could about those things. It's car stuff right Part of learning is trying to help others and getting their feedback on results. Another part of learning is having people like you question or comment on my advice to others. Makes me go back and think about my approach. Yes diagnosing via the net is hard. I don't have the car before me. I can't see it, touch it, feel it, smell it, hear it, taste it, talk to it, and it can't talk to me. So ya it's hard Take care.