Mike Murphy

vza

That would be great if turned out to be the solution. Got to say Porsche got things bass ackwards. Why didn't the blinker CEL come on when I was running the engine with lost timing and potentially bending the engine up. It only blinked when I set correctly and when it sounds like its running fine. Such a tease.v

paulofto

I installed NGK Iridiums in my 03 S at the 60,000 mile service and have put on just over 10,000 miles with them. I've never had an issue. There are many members here and on the 986forum who use them as well and speak highly of them. Make sure they are the correct ones since there are a few different heat ranges.

vza

Well here's an update. Odd....Put a code reader on and got the following. PO300 Sum Misfire
PO304 Misfire Cyl 4
PO305 Misfire Cyl 5
PO306 Misfire Cyl 6
PO150 Pending o2 Sens Cyl 1-3
The tap/tick was coming from Bank 1, when I retimed it the noise was gone but now I'm getting misfires on Bank 2? Does this make any sense. Does the code reader read the blinking CEL as well cause it went from blinking to stationary. Didn't restart the car just plugged the OBD2 into the port and turned on the ignition.

Anything would be helpful. I'm going to recheck the Coil Wires on Bank 2. Thanks V

vza

I did have the intake off with injectors pulled out (not out of the rail) on Bank 2 maybe they're not seated would that cause a misfire w blinking CEL? Also the front bolt on the fuel rail where it bolts to the intake was stripped. Hopefully this is a totally different issue than the lost timing on Bank 1.

Mike Murphy

vza

Yes I did but the misfire is showing on the opposite bank....the bank that was not out of time. I'm going to check the coil pak wires and for vacuum leaks....there was a hissing sound but thought that was normal(1st porsche), I'm not sure wether it's ok to run the engine.

vza

UPDATE...I checked the electrical connectors for bank 2 which I did have off at one point ...they were good. Checked for vacuum leaks, was able to tighten up the tubes going to plenem, leads going to correct plugs. Car was idling ruff ...lots of stalls, low idle 500 rpm's. Then it remained running at about 1000rpm's or so. Removed oil cap w no change,removed AOS tube....stalled. AOS is new. Disconnected MAF and car ran better, revved it sounded good. Didn't run good when re-connected, heard a sound like hitting a spoon on a pot when revved. I assume a misfire. No CEL, I have a weak batt so many times I have to do a quick charge to start, so previous CEL's were cleared. Put code reader on although there was no CEL and there were pending misfires on 4-5-6 and emission relevant but CEL never came on! I'm stumped at this point. I might try swapping out the IRIDIUM plugs to OEM. I did not gap the plugs ,from what I understand they are pre-gapped .8 mm. Don't have a durametric so can't read Cam Deviation. It sounded and revved better w/o MAFbut I don't know if I want to start replacing everything and chasing my tail unless I'm sure. I did have the snorkel out and cleaned it on the outside, I did touch the MAF with my finger to see if it was dirty. Then of course read not to touch it. Please chime in. Again, I'm concerned mostly with the possibility of bending valves when I was running it with lost timing but I'm really thinking it is a different issue now. thanks v

Macster

Since you mentioned the battery....I watched a Porsche tech start the engine in a Panamera. The engine ran fine for a bit then started to run rough. CEL came on. Other warnings came on. Engine died. Tech turned off the engine and let the car sit a while. Went to start the engine and it fired right up and was running fine but shortly afterwards started acting up again. Tech turned off the key. Then he told me it was a low battery low because the alternator was not putting out enough electricity.

My point is you have to be sure the battery is good and the alternator is producing enough electrical power to top up the battery and supply the rest of the engine and car electrical needs.

However, I'm not sure the battery (or even the alternator is the problem). That the engine ran better with the MAF disconnected sure points a finger at the MAF. I know in one case a Boxster owner reported misfires on just one bank and it proved to be the MAF. If you opt to replace the MAF be careful. With the earlier cars Porsche changed the MAF part number and the new MAF while it bolts in, connects to the harness, requires a DME flash update otherwise the new MAF won't work.

Another explanation for misfires on just one bank is the VarioCam solenoid/actuator is acting up on that bank. If this happens the cam timing can be off -- retarded when the DME commands it to be advanced or advanced when the DME has commanded it to be retarded (or advanced rather than normal or normal instead of advanced, something like that). What can then happen and I observed this with my Boxster when the VarioCam solenoid/actuator on the passenger bank went bad is the DME will adjust fueling the bank in order to get the O2 sensor readings it expects. But because the cam timing is not right the fueling adjustment will not succeed and in fact cause the cylinders to go into misfire.

While my car's engine didn't misfire I observed the passenger side #1 short term fuel trim make huge swings as the DME made adjustments to the fueling. When I described this behavior to the tech he filled me in on the why and told me had it continued the engine would have started to misfire. As it was I turned off the engine and upon restart the VarioCam solenoid/actuator had recovered and worked just fine on the 30 mile drive home. But the next day in just a mile or so on the way to the dealer the symptoms came back and the engine was acting up something fierce on the service department forecourt.

As for plugs, I always advise sticking with factory plugs. With a sick engine that is not the time to experiment with plugs. Also, whenever you install plugs beforehand always check and set the gap if necessary. Furthermore do *not* use any anti-seize. This can contaminate the O2 sensors.

vza

This all started with replacing the bank 2 solenoid. Was getting CEL for solenoid actuator ,replaced the solenoid now getting misfire in that bank. Think I'll swap out plugs for OEM recheck timing on back 2. If that doesn't change anything install a new MAF sensor. Not sure how to do flash update for MAF just ordered after market from Pelican...they confirmed the right part with no mention of a flash update.

Macster

Well, I just have the one bad solenoid experience but what happened was the tech replaced just the solenoid. After a short while -- a day? -- the symptoms came back. Diagnosis? Bad actuator.

Believe it or not I did not have to pay for the labor to replace the actuator. What happened is the tech for reasons I don't know failed to mention to me that at least in the case of the Boxster the guidelines were to replace the solenoid and actuator. There was no way to distinguish between the 2 components which one was bad. (It is not viable to replace just the solenoid then button the engine up and road test the car and if the symptoms return to then go back in and replace the actuator. The guidelines arose from the factory having faced early on having the tech replace just the solenoid only to have the car brought back with the same symptoms and having the tech go back in and replace the actuator.)

Had he mentioned this to me I would have directed him to replace both items. The dealership management knew me well enough to know this is how I roll and so held me blameless for the failure of the tech to replace both items and while I had to buy the actuator -- not cheap -- I didn't have to pay for all the labor -- essentially a duplicate and then some of the labor to replace the solenoid. The dealer ate this cost.

The main point I want to get across is that if the solenoid is suspect and if it is decided it needs to be replaced the actuator should be replaced too. There is a lot going on with your car's engine but the possibility is very well, possible, that like in the case of my Boxster both the solenoid and actuator are bad.

After the actuator was replaced the engine ran fine and remained free of any VarioCam solenoid/actuator symptoms/signs of trouble from both the new hardware and the old/existing hardware on the other bank from after the repair to 50K+ miles later. Had I kept the car I would have expected this good behavior to continue.

vza

Thanks for the response...well I thought of that...checked the resistance on the solenoid and it was bad. So I took a chance and just replaced it. No new CEL on the the actuator/solenoid but I didn't drive it yet. I'm crossing my fingers. I think I'm going to check the timing on that bank make sure its dead on.V

vza

Just an update....Re-timed Bank 2 to rule out any timing issues. Can say with confidence the Banks are dead on. Started up and idling at 900 RPM's. Revved engine and it sounded really good. Let it warm up almost to op.temp and thru a CEL. Codes were:
P0130 Precat Cyl 1-3 Pending(What ever pending means)
P0150 Precat Cyl 4-6 Pending
P1316 Misfire #4
P1318 Misfire #6
P1319 Misfire Emission Relavant
P1317 Misfire #5 Pending

I'm noticing I don't throw a code till the engine starts getting warmed up. Any suggestions, I ordered a MAF sensor but not too sure. Been reading a leaking exhaust could cause the O2 codes but what about the misfire codes. Never heard anything misfire. My exhaust does sound a little loud,my 1st Porsche so not too sure if its normal or not, I had to hammer out broken bolts on 2 of the brackets welded to the muffler and did bend the brackets up a bit but hammered them straight again. Also noticed a few small splits in the seems of the muffler. Any procedure to find an exhaust leak? Thanks V

Anker

Pending codes are intermittent codes that have been thrown and cleared themselves. If they don't come up again within 40 drive cycles they removed.

I think you have bent exhaust valves. That would explain all of the codes. If an exhaust valve doesn't seat properly it or the seat will eventually get burned.

Macster

Let me start with this: You have too many possible things going on. Timing. Bent valves. Misfires. Exhaust leaks. You have to start eliminating these possible issues and at the same time not creating new ones.

Unless I missed it while you know the timing is ok statically you don't know its ok dynamically. That is I'm referring to the possibility the VarioCam actuator is acting up but doing so after the engine warms up some.

But let's leave the actuator out of this and consider other things.

The engine controller constantly measures each cylinder's contribution to the flywheel speed for every power stroke. If a cylinder's contribution is below (or above) a threshold for too many revs a misfire is flagged. But misfires do not have to be obvious.

There is also the possibility one bad cylinder can have a detrimental effect on other cylinders to the point the other cylinders do not operate as they should and this results in these cylinders being flagged as misfiring. Technically they are but it is not their fault.

You mention the possibly of an exhaust leak. Exhaust leaks can affect O2 sensor performance. Proper O2 sensor performance is critical as this is the only way the engine controller has of knowing how its attempt at correct fueling is working out. So addressing exhaust leaks is very important.

Some exhaust leaks can be found by running the engine and just listening. Without running the engine maybe a smoke test would allow one to identify an exhaust leak? I've only dealt with one or two exhaust leaks, and these years ago, and the leak source was obvious.

Anker raises the possibility of bent valves, exhaust valves. While I do not believe this is the case I could be wrong. A compression test even just a leak down test should make it clear if there is any exhaust (or intake) valve leak.

A bad injector can cause grief for the entire bank. One injector doesn't operate properly. Injects too much fuel or not enough. The bank's #1 O2 sensor reading indicates a fueling problem. The engine controller adjusts the fueling of all cylinders of that bank. So two otherwise properly operating cylinders now become incorrectly fueled. The bad injector may not operate within spec even with the engine controller adjusting fueling to try to compensate for it.

The result is 3 cylinders are misfiring. One due to a real problem the other 2 do not have any real problem.

Lots of possible explanations. Only you can eliminate these until you have found and eliminated the one (or ones) that is (are) causing the engine to misbehave. You have to approach this in a systematic and disciplined manner. The tendency (been there got the t-shirt) is to jump from one possible thing to another like a honey bee on meth in a flower garden. But the proper way is to consider the possible causes and based on observation, measurements and other inputs, for instance from monitoring various engine telemetry, picking the most likely cause for the behavior and eliminating that.