kukaepe

I've got a 2003 C2, NA 3.6L 3 chain engine with a reoccurring P0344 code. Is it possible to reset the valve timing, using the proper tools to lock the crank & cams and loosen the VarioCam + bolt, with the engine in the car. Thanks in advance for your help.

Ahsai

Jake mentioned before it could be done but it won't be easy. However, I bet Jake can also assemble the whole engine blind folded with one hand tied behind his back.

I would not attempt that because the space is tight (rear subframe and coolant hoses in the way) and that variocam+ bolt is super tight. I would at least do a partial drop of the engine but even that I think it would be difficult.

P0344 complains about the reluctor of the bank 1 intake cam. One thing you can try is remove some collant hoses and the cam position sensor and stick your pinky inside to feel around. May also turn the engine by hand and recheck. Or use a borescope carefully aiming at the cam position sensor opening.

kukaepe

Ahsai: I'm preparing to remove the engine. I obtained the tools to set the valve timing and prior to dropping the engine, I thought I would check if the cam locking tools would line up. Set the engine to TDC per the Bentley manual and found that the exhaust cam lined up OK but the intake cam would not. I tilted the tool and inserted it into the intake cam slot and took a photo to illustrate how far off the cam timing was. Is this consistent with a reluctor wheel on the bank 1 intake cam being off. Could the timing chain have jumped due to a bad tensioner and/or a backfire on start up? Your opinion would be greatly appreciated.

Ahsai

The intake cam timing is way off (retarded). Not sure what caused it but you've likely found the cause of your code.

Has there been an engine work before?

kukaepe

I bought the car with this problem. I have all the repair receipts from last owner for last 30K miles (currently 51.6K miles) which shows all work at local Porsche Dealer. Only major work was replacing rear main seal. I was thinking about retiming the engine and replacing all 3 timing chain tensioners. Do you think I need to worry about the reluctor wheel being loose or just retime the engine? Thanks again in advance.

Ahsai

Most likely not the reluctor wheel given how much your timing is off.

kukaepe

Ahsai: Thanks again for your help and advise. Do you have a theory as to how the timing got that far off on Bank 1?

Ahsai

Perhaps it jumped a tooth when someone opened the imsb flange without locking the engine at TDC first.

kukaepe

Ahsai: I got the engine out with the help of the car being on jack stands quite high and a hydraulic table I picked up from Harbor Freight, not to bad a project doing the work without a hoist. I separated the transmission from the engine and began the removal of the valve cover on the left bank. Following the Bentley manual, I had to rotate the engine (in the direction of rotation) in order to get the "shoe" to match the scavenge oil pump opening while lining up with the large hex on the intake cam variocam unit. I slightly loosened the locking bolt for the variocam thinking the taper would hold the unit to the cam. I then rotated the engine (in direction of rotation) something less than 720 degrees to get the TDC locking pin into the crankcase. To my surprise, now the alignment of the cam slots were in perfect alignment on both banks and the locking tool installed with no problem (see photo). The orientation of the intake cam lobes on #1 are consistent with the Bentley manual.

I also then removed the left bank chain tensioner and the plunger and spring fell out in my hand. See photo of the parts with spring with a coil or so broken off. I am thinking that the problem may have been caused by a "stuck" variocam unit and/or related to the chain tensioner. Do you have any thoughts and/or recommendations as to how I should proceed from here?

Ahsai

Good progress! When you said you slightly loosen the locking bolt of the variocam, did you mean the center bolt on the variocam actuator? That bolt should be very tight and can only be loosen with a special tool counter holding the big hex collar. Was the bolt very tight?

That bolt will need to be replaced. You will need to retime bank 1 with a new tensioner and check the timing on bank 2. Can also retime bank2 if it's out (e.g., can't fit the cam alignment tool).

kukaepe

Ahsai: Yes I did loosen the locking bolt and used the special tool holding the big hex collar, the reason I had to rotate the engine clockwise was to get the holder "shoe" to properly intersect the scavenge oil pump opening. The bolt was very tight. Do you think the original P0344 issue came from the tensioner? Do you think I should replace the variocam unit as well? I would hate to put this all back together and have the P0344 code return again. Thanks again in advance for all your help.

Ahsai

I think the P0344 was due to the excessive cam deviation (shown in your photo). The DME was confused and thought the reluctor was the problem.

What caused that deviation is the question. A broken tensioner can definitely cause the cam to jump a tooth or two. I know that you can remove the cam actuator from the intake cam (careful with those thin washers and put them back as they came out) but I'm not sure if you can bench-test the actuator.

kukaepe

I'm proceeding slowly with work on my 996 engine.

I've decided to replace all 3 timing chain tensioners and the seal on the IMSB flange. Oil dampness or "sweating" below the RMS seems to be coming from the IMSB flange seal. RMS was replaced at the dealer in 5/2011 approximately 17K miles ago (current mileage 51.6K) and does not appear to be leaking. IMSB felt smooth with no axial play and the seals looked as new. Should I replace the RMS and IMSB anyway?

I am still on the fence regarding replacing the intake cam variable timing sprocket. Are failures or misbehavior of these units common? I am OK to replace this part if it is needed but not to keen on buying a $500 part unless it is necessary...does anyone have any experience with these VarioCam + intake sprockets?

Based on lurking about this forum for a few months to understand common parts that require replacement, I'm considering replacing the oil cooler seals and the air/oil separator while the engine was out. Advice?

I am also considering replacing the coolant expansion tank while the engine is out. It is not leaking but it is 14 years old and it looks like it would be tough to change with the engine in the car. How hard is it to change with the engine in?

Are there other items I should consider replacing while the engine is out?

Thanks in advance for your help and consideration.

rockhouse66

Once you are all the way in to the IMSB flange seal, another fifteen minutes and you would have the new IMSB installed. So why wouldn't you just do it?

kukaepe

I thought I would close out this thread about the PO344 code on my '03 996. Best I can tell the root cause was the failed tensioner on bank 1. I'm still puzzled how the cam timing stayed proper on the exhaust cam while it jumped backwards from rotation on the intake cam. In the end I replaced all 3 chain tensioners, retimed bank 1 valve timing (bank 2 was spot on) and put it back together. Changed the oil cooler seals and Air/oil separator while engine was out as well as a new DM flywheel and clutch. Car is sounding and running great. Knowing what I know now I would have removed the bank 1 tensioner before removing the engine but I don't think the problem could have been resolved without removing the engine.

Thanks to Ahsai and the other forum members for coaching and helping me tackle and succeed at this repair. This is a wonderful forum with a great members who are willing to help a newbee like me. Thanks again.