P0344 Reoccurring OBDII Code

[kukaepe]

I'm recently acquired a 2003 Carrera Targa w/3.6L 3 chain engine.  Both catalytic converters had honeycomb guts rattling so it was hard to hear anything but the bad cats.  I'm getting a reoccurring P0344 code and am concerned with an IMS bearing on it's way out, car still runs OK but not driving it until I figure out what the problem is.  I removed both cats and the driver's side muffler, set the engine up on TDC #1 and pulled the cam plugs on the left side.  The exhaust cam slot seems to line up properly but the intake cam appears to be rotated counter clockwise about 1/2 the width of the slot (about 10-20 degrees) from proper line up.  I tries to attach photos but the files exceeded size limit.  Is it reasonable to suspect the variocam adjuster solenoid (closest to flywheel) on the left bank as a possible cause of the intake timing being off?  Thanks in advance for your input.

[Loren]

 

There is rarely any sign that the IMS bearing is going before it does. With the age of the car I would almost think that if it had a problem it would have already happened.

 

This fault code (P0344) is pretty clear.

P0344 Camshaft position sensor 1 - open circuit

 

Possible fault cause:
- Camshaft rotor (phase sensor wheel) damaged.

 

You need to the check camshaft rotor for damage.

[kukaepe]

Loren, how do I do that remove the LH valve cover and inspect it?  It's on the opposite end from the flywheel on Bank 1 correct?

 

[Ahsai]

The only way I know to pyhsically inspect the reluctor is by remving the bank 1 cam cover. I posted a photo here http://rennlist.com/forums/996-forum/905331-p0344-and-p0349-error-codes-no-cel.html

 

If your intake cam end slot is truly 10+ degrees off, you shoukd also retime your engine because that's 20+ crank degrees (spec is 0 degree +/- 6 crank degrees).

 

 

[Ahsai]

And you will need this tool kit https://www.amazon.com/Porsche-Camshaft-Alignment-Timing-Tool/dp/B00L0ZYKRI

[kukaepe]

Ahsai & Loren:  I removed the bank 1 cam sensor on the left rear of the engine.  I was able to get the tip of my little finger into the hole and feel the reluctor to learn if it was loose from the camshaft.  The best I could tell it was not loose.  I noticed that the wiring connector (male portion) and the speed sensor (female part wiring connector) were quite wet with engine oil.  Could the sensor be bad with oil leaking into the wiring connections causing an intermittent/open connection?  It appears that the intake cam is slightly retarded, will the VarioCam chain sprocket on the intake cam be put into a retarded position if the ECM doesn't see a proper cam sensor signal?  Thanks to both of you on your help with this challenge.  Thanks for the link to the similar post Ahsai, do you know the final cause of of Aerkuld6's P0344 issue, I didn't see it in the link.  

[Ahsai]

The variocam actuator on the intake cam head will park in a neutral position whenever the engine is not running and there is no oil pressure. The intake cam retard could be from worn chain pads.

 

Unfortunately I don't know the reaolution of that thread. The OP never came back.

 

Regarding the cam sensor, you may want to clean up the oil and the electrical conracts. Not sure if it will help. So you have Durametric? If you do, you can get the cam deviation reading.

[kukaepe]

Ahsai, unfortunately I do not have a Durametric.  I may try replacing the cam sensor and installing new catalytic converters and starting the engine to see if the code comes back.

[kukaepe]

Since my last post I have been trying to resolve this reoccurring PO344 code by eliminating the relatively simple things that may be related to an intermittent circuit for Bank 1 cam position as well as performing other maintenance.  I replaced both cats, replaced the spark plugs (52K miles on car so probably due), replaced the Bank 1 cam sensor, replaced the Bank 1 variocam timing solenoid, cleaned all wiring connections between the cam sensor and the DME with "deoxit", ran temporary wires between the DME and the cam sensor.  Nothing has changed still getting P0344 code.  I have not purchased a 3 car version of Durametric yet but I can do that if it will help me resolve this situation.  The tools to reset the cam timing are not very expensive and I was curious if the cam timing can be reset with the engine in the car.  I am also thinking it may be good to replace all 3 timing chain tensioners at the same time as resetting the cam timing.  I am quite puzzled by this problem as the car sounds and runs great, I believe the intake valve timing is advancing as around 4K rpm the power and sound of the engine definitely changes which makes sense with more advanced intake valve timing creating overlap with the exhaust valves. Thanks in advance for your suggestions regarding resetting of cam timing.

 

2003 C2, 3.6L 3 chain engine   

[JFP in PA]

I think you are getting ahead of yourself here.

 

The code you are getting, as Loren indicated, if for potential cam rotor problems, not cam timing.  Before needlessly changing any additional parts, you need to take a look at that rotor to see if it is out of position or in some way damaged.   That code is specific.

[kukaepe]

JFP, your point is well taken but to inspect the cam rotor I will have to remove the engine.  I'm trying to resolve the issue without removing the engine.  I will be doing this work at home in my garage without a hoist and engine removal won't be an easy chore.  If I can check the valve timing without removing the engine, I am willing to try this first.  Thanks for your help and comments.

[JFP in PA]

Sometimes, you just have to "bite the bullet".  Cam timing and deviations can be checked with an appropriate Porsche specific diagnostic tool such as the Durametric or PIWIS systems.  That said, if your cam timing was far enough off to be causing problems, it would throw separate codes, which you do not seem to have.

 

The rotor can be often be inspected, albeit with some difficulty, with the engine in the car using a quality bore scope.  But this is not for someone without specific knowledge of what they should be looking for and a great degree of care as it requires rotating the engine with the camera probe inserted into the cam drive area, where it can quickly become hopelessly entangled, which will then require dropping the engine just to get it out without causing additional problems.  This entanglement usually also permanent damage to the bore scope, which is anything but cheap to fix.  Caution is the operative by word here.

[kukaepe]

I'm preparing to remove the engine and thought I would check the cam time one last time.  I bought the tools for setting up the timing and set the crank up at TDC per the Bentley manual.  The tool lined up fine on the exhaust cam but would not line up with the intake cam on Bank 1.  I tilted the tool and took a photo of it when it lined up with the slot in the intake cam.  Photo is attached.  Is this consistent with a reluctor loose from the camshaft?  Could this have been caused by a chain jumping a tooth due to a bad tensioner and/or a backfire on start up?  It seems that I will definitely need to retime the engine but should I also continue to pursue the reluctor wheel?  Thanks in advance for your thoughts.

[JFP in PA]

I would try rotating the engine 360 degrees by hand and check the tool fitment again.  Sometimes you catch them 180 degrees off.  If the cam locking tool does not go in then, you have a cam timing issue, which I seriously doubt is the reluctor..

[Schnell Gelb]

On 6/5/2017 at 8:59 PM, kukaepe said:

I'm preparing to remove the engine and thought I would check the cam time one last time.  I bought the tools for setting up the timing and set the crank up at TDC per the Bentley manual.  The tool lined up fine on the exhaust cam but would not line up with the intake cam on Bank 1.  I tilted the tool and took a photo of it when it lined up with the slot in the intake cam.  Photo is attached.  Is this consistent with a reluctor loose from the camshaft?  Could this have been caused by a chain jumping a tooth due to a bad tensioner and/or a backfire on start up?  It seems that I will definitely need to retime the engine but should I also continue to pursue the reluctor wheel?  Thanks in advance for your thoughts.

The interesting question is - How did the Intake cam become so out of time ??

 

[kukaepe]

 I removed the engine and started looking into why the intake cam was retarded.  See photo of what came out in my hand when I removed the chain tensioner for the left bank.  I'm assuming the slack in the chain resulted in skipping a tooth or two on the intake cam only as a result of the chain tensioner failure.  I'm wondering if I should also replace the variocam + sprocket.  I think I will replace all 3 tensioners in the process of re-timing the engine.  Any thoughts or theories in how this tensioner failure could lead to the exhaust cam remaining in proper time while leaving the intake cam in a retarded position by a tooth or two??  Thanks in advance...

Edited June 21, 2017 by kukaepe

[Schnell Gelb]

Suggest you postpone a complete diagnosis until you have removed the cam covers. Then look for some causes there.

[kukaepe]

I thought I would share the final result of my chase of the P0344 OBDII code.  I believe the root cause was the failed chain tensioner on Bank 1.  I'm still a bit confused how the exhaust timing on Bank 1 could be in line while the intake timing on Bank 1 would up retarded.  Given the rotation of the chain is clockwise, that means the chain would have to jump opposite rotation which I can only theorize was due to a backfire during start up but that's only a guess.  I replaced all 3 chain tensioners, retimed bank 1(bank 2 timing was spot on) and reinstalled the engine.  While the engine was out I replaced the oil cooler seals, air/oil separator, DM flywheel and clutch.  Car is running great, no codes or CEL and passed smog so I could register the car.  Thanks to all who helped me with information and suggestions, this is a great site and forum.  Mahalo to all, Mike

[dporto]

Wow, great to hear this! A broken chain tensioner could have caused so much more damage - I think you got really lucky!!!

[kukaepe]

dporto:  I agree, I definitely dodged a big bullet on this one...