NOOB in need of help with P0343 Code

[navygse1]

Hello everyone,
Hoping someone has a quick cheap solution for my P0343 code for my '02 GLS 4Motion wagon with 80K miles on the ATQ 2.8L 30V V6.

Backstory: Picked up the VW on Thursday (24 May '12), good shape overall and runs very well. When I was inspecting the vehicle before buying I noticed the coolant bottle was full of gunk and brown, so I figured a coolant flush was in order to say the least. I drove it home from Ramstein AFB to my post in Stuttgart (I am a Soldier stationed in Germany...Passat is US spec!), car ran well all the way home with no CEL or other signs of issues. Temp gauge was rock solid at 190 F, which I hate how hot German cars run...but I digress.
The next day I attached a flushing "T" to the outlet of the heater core next to the battery. (My online research showed that ANY other coolant/additive mixed with VW G12 (or G12+) will turn it brown). Spent most of the day flushing the system, steam cleaning the engine and replacing brittle/broken/dry rotted vacuum lines and hoses. Some water got in the spark plug wells and the engine ran rough...missing and hesitating, etc. During all the cleaning and dry rot/ heat damage repairs, the CEL came on. I had expected this with all the damaged vac lines, so no worries. Upon completing all repairs and clearing each code, I noticed P0343 "Cam Sensor A High, bank 1" which puzzled me. I assumed I had gotten water in a sensor, so I went through and checked almost ever connector I could find on the engine...all were dry. This brings me up to my current issue...

I have ordered the Haynes manual and will order the Bentley once Amazon comes under $100!

Forum research has shown this code as a likely sensor issue, timing belt issue or several combinations of other issues.
What I have done so far:

1. Did a visual of the timing belt by removing the tops of the inspection covers. Belt is in good condition and did not notice any major issues. When the engine was cold the belt did have some slack on the non-tension side, but once it was started for the day it was tight upon numerous following inspections. I have not yet checked the cam sprockets to see if they are zero as when installing a new belt.

2. Pulled both Cam Sensors and took meter readings with the following results:
Across Pins:

Sensor A Bank 1, Front Pass Side
+ and - = 4.57 Mohms
+ and 0 = 11.8 Mohms
0 and - = open (however with the leads reversed 3.48 Mohms)
0 and + = 11.9 Mohms

Sensor B Bank 2, Rear Driver's Side
+ and - = 4.67 Mohms
+ and 0 = 12.3 Mohms
0 and - = open (however with the leads reversed 3.5 Mohms)
0 and + = 12.2 Mohms

As the readings were similar, I assumed there was nothing amiss (after all, these are super basic sensors with no moving parts to wear out!) but I took the opportunity to swap sides in the hope that I would get a new code for the opposite bank...but no luck! The same code reappeared.
Upon checking my codes numerous ways, it is thrown almost immediately at startup, but sometimes the CEL does not indicate it until after shutdown and a restart.

I am preparing myself to replace the timing belt, but am hoping someone may have an alternative that I missed as the engine runs great! I am not too concerned about doing the work as I am putting in a lower Tstat anyway since I don't like it running that hot...and someone PLEASE tell me it is NOT required to remove the entire front clip to do the work as I read in a 60 step process on one of the forums! I think I can do the job with out removing anything more than the radiator, but that is a first look best guess without familiarity of all the engine components...does anyone have the Cam TDC zero tool they want to sell??? (EPS has them for just under $200 and Ebay I saw one for $75)

Anyway, please let me know your thoughts and ideas! I am hoping I am jumping the gun...especially since VW recommends the belt change @ 105K miles for my 2.8L 5 valve.
Thanx in advance!
Mike

[AndyTR32]

Is the car leaking any oil? Do you hear a loud wrapping sound when you start the car (cam chain slack). Perhaps it could be the cam chain tensioner failing. However, when my cam chain tensioner failed it gave a tensioner specific code.

Since the bay has seen a lot of water as of late, maybe you've got a ground somewhere. I'm sort of clueless to the code.

I mostly replied to let you know that blauparts.com rents the TDC tool and also sells the TB/WP kit. I hear you can change the timing belt w/o putting the front end in service position but I don't have any experience. Something critical like a timing belt may be worth the extra steps and time to be sure it's done correctly.

Good luck,

Andy

[navygse1]

Greetings Andy!
Thanx for the heads up, I am going to check the chains this weekend and see how the belt sprockets line up, they should be close to perfectly horizontal if my guess is right.
The engine is not leaking any oil on the outside, but there was some oil in the spark plug wells. I do hear some noise upon initial COLD start up, but I sprayed some belt stopslip on my VERY worn serpentine belt and the noise stopped and then when it came back, it sounded different...BUT, I will check the chains this weekend.
I am hoping as you point out, with all the water and attention the engine got last week I believe it could be a ground issue...just seemed odd and I was not able to find ANY water in or around the cam sensors. Do you happen to know what the sensors are that are on the opposite sides of the cam sensors? (Drivers side front and pass side rear under the intake?) The one on the driver side front has some corrosion on it, but looks intact and the connection is clean and dry.
Thank you VERY much for illuminating me on the "Service Position." I have seen numerous VW articles describing putting the car in the service position and I was clueless as to what that meant.
Also, thanx for the blauparts website, they have alot of parts I may need, but the tool kit isn't shippable outside the lower 48, so I doubt they will send it to my APO...but it is an awesome kit and website.
I really appreciate the feedback and the new directions I will try.
I will post once I find more!
Mike

[AndyTR32]

I'm not sure which sensors you are referring to. The only sensors are the cam position sensor front right and rear left of motor and the cam tensioner connectors front left and rear right of motor. I've actually ran with the cam tensioner unplugged and got a cel. Maybe you've got a short in the pins there. Make sure all of those are nice and dry.

Also, oil in the plug wells means the PCV is probably clogged. Get those hoses replaced ASAP. $100 bucks and a few minutes of your time. If the other seals aren't leaking maybe someone replaced them but forgot to replace the spark plug gasket.

Sucks about blauparts shipping atleast you can find out what you need from there.

[navygse1]

Hello Andy,
You are correct, I thought those were sensors, but realized they were the tensioners when I saw a pic on Amazon (damn thing costs $654!), the connector was unmistakable.
I have fixed all the PCV hoses, I replaced the brittle and broken plastic with a bunch of 5/8" heater hose I had and clamped it over the very sturdy round ends that clip onto the valve covers.
I have question on your 2.8L, does the engine idle rough when you take your oil cap off? My crankcase is under quite a bit of vaccuum which seems odd to me, but it runs great with it on so I assume this might be ok...please let me know your thoughts.
The PCV hoses are flowing very freely now and I did not notice any more oil in the wells when I took to the top half of the engine apart this morning. I even made a video with commentary!
I took the valve covers off this morning and everything looked fine. Both chain tensioners were in excellent condition and the chains were very taught. Additionally, the cam belt sprockets very both perfectly matched up (albeit they were vertical), but still they were both in the same direction.
I believe it is water grounding out somewhere and my confidence in the engine is restored. The code is still coming back, but I will go through and electrically troubleshoot the system at my lesiure.
One thing I did notice today was I beleive when I do replace the belt I will have to remove the front clip. I tried to get my hands down to put a socket on the balancer bolt and my gorilla hands have no room between the engine and radiator...so I will dread the day I do that job...but THAT is for another day!
I will update as i dig into it more...have a great weekend!
Mike

[AndyTR32]

I'll check the idle with the oil cap off next time I drive the car. The crankcase is under pressure so I wouldn't be suprised at all.

[Slimjimmn]

noobs, use the search function.

I did full writeup on 2.8 belt change without removing the front clip

[navygse1]

Greetings Andy!
Well, the wagon still runs great and I haven't been able to find much, but ever since you mentioned the noise at startup I have heard a knock at startup with the engine cold only. I had my wife start it after sitting for three days with me listening and it seems to be coming from the top drivers side valve cover. (Bank 1 or A, right?)
I suspect the chain may have jumped and the tensioner is slack at startup.

Is the tensioner supplied with oil for keeping the chain taught?

At the moment I am just goign to keep driving it and checking the CEL to make sure nothing changes and prepare for a tensioner change and then doing the TB and water pump.

Did you ever check to see if the crankcase was under hi vacuum at idle and if the engine stumbles?

Other than that, the car runs and drives well and the mileage is good...kinda stumped.
Thanx for the assist and feedback.
Mike

[AndyTR32]

My car idles a bit rough sometimes regardless. I think it is the idle stabilization valve or a dirty throttle body. I will check with cap off tomorrow.

Driver side is bank 2. If the cam tensioner fails you should get an adjuster specific cel, that's what both of mine did.

The tensioner does use oil pressure so it can be noisy if the car has sat for a long enough time for the oil to drain (not sure if it will completely drain the tensioner unless the tensioner is removed). If the chain is slacked it will wrap loudly. This is a premature sign of tensioner failure.

When I replaced both of my tensioners, there was a loud knock after initial startup. Almost as loud as a bent valve. Goes away in about 2 minutes.

If the cam chain is off a tooth, you'll get a cel. Off 2 teeth and you'll bend a valve and get a cel. So if you have no cel, the most I'd do is replace the tensioner seals. The tensioners are expensive so don't replace them unless you're getting a cel(cam adjuster related). Unless of course the wrapping is bugging you, it may make sense to replace them when the car is torn down for the timing belt. Check amazon and ebay for refurbed tensioners and save yourself $300.

I think the previous owner of my car neglected the leaks for too long and the tensioners failed.

Hope that helps,

Andy

[navygse1]

Finally! I was going through the wiring harness inch by inch and found the culprit. The bright green connector that is on the driver's side firewall under the coolant tank was not seated properly. The driver side cam sensor connector is wired directly to the main bundle with the individual three wire loop only having a few inches before it goes into the main bundle, however the pass side cam sensor has a jumper that goes from the front of the engine all the way back to the driver side firewall. I was checking continuity with my ohm meter and after tracing the wire all the way back and I gave a tug on the connector and it just popped off. It didn't feel right and when I inspected the contacts, they had dried soap and water residue all over them. When I tried to put it back on, it only went partially together and there wasn't the confidence building SNAP that you get when pushing the connectors together. I compressed the release spring as I put them together and it seated fully.
Near as I can guess, someone must have been working on it before I bought it and only had it partially on. Then when I was steam cleaning the engine, it must have come loose and allowed water in to break the contact.
Appreciate the feedback, this was a real PITA but I am finally glad to have it fixed!
Mike