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Discussion Starter #1
I have a problem with my Passat 2.8V6 2004. 1,5 year ago engine belt is renewed together with rollers, waterpump, cam tensioners and chains.
After a year I had a loose timing belt, no damage on the engine. The tensioner on bank 2 is renewed, is was leaking oil.
Now i have the problem that after not using the car for a few days, with starting I have a rattling sound. I have the following code

17930 - Camshaft Adjustment; Bank 2
P1522 - 35-10 - Malfunction - Intermittent.

Is it possible that the cam tensioner is bad or maybe a leaking oil valve?

Hope someone can help me.

Regards,
Harry
 

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Likely a fault of the Cam Chain Tensioner, the one that was replaced if I understand correctly. I would have the valve cover removed to inspect, and very soon. By the way, did you learn what caused the timing belt to loosen? That should not happen even after high mileage.
 

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A rattle for 1-2 seconds is normal, especially in hot weather, but if it's longer or it sets a code, the tensioner is probably bad. I would also check oil pressure as that is what actuates the tensioner. While that is a more common issue on the 1.8T, there have been a couple of V6 with the problem.
 

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Discussion Starter #4
The rattle is only with starting, only one second. Car runs fine. Maybe I can check the oil pressure valves in the engine for leaking?
Timing belt was loose after 15k kilometer. The guy who did the timing belt forget a camshaft oil seal, so timing belt was wet of oil.
There is a new one on, and now I check the belt sometimes. Maybe a bad tensioner.
The code is only on bank 2. Are there 2 valves in the engine for holding pressure to the head of the engine?
It's a nice car to drive, but at this moment a have some difficult problems.
 

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If the light came on after the timing belt was replaced due to the oil leak, it may be off a tooth on the gear and unrelated to the rattle. Mine rattled for almost 60K and never more than 1 second on startup. What oil are you running? The proper 5W40 or 0W40 may reduce the rattle compared to a 5W30.
 

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Discussion Starter #6
After the timing belt change i had no problems. After a month, it was cold here in Holland, the rattle started. I have checked with vcds the timing of camshaft and the timing is okay. Maybe it's better to lift the valve cover.
 

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The CCT tend to rattle more when it's hot out. I would double check all exhaust mounts and heat shields to make certain they are not causing the rattle but the fact that the codes keeps coming back indicates there is an issue with either the CCT, wiring or the cam sensor. Swap the 2 sensors and see if the code changes to bank 1.
 

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Discussion Starter #10
Code didn't changed to bank 1, sensors are okay. Today I had the following codes.
2 Faults Found:
17930 - Camshaft Adjustment; Bank 2
P1522 - 35-10 - Malfunction - Intermittent
16805 - Warm Up Catalyst; Bank 1
P0421 - 35-00 - Efficiency Below Threshold
Readiness: 0000 0001

Think I will lift the valve cover and check the CCT pads. CCT should be new, told by the guy who fit it. Is there a way the check the CCT?
Last time the mechanic put a lot of liquid gasket between the valve cover and the gasket. Is it possible that the liquid gasket can block the oil for the CCT?
 

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It can block the oil port to the CCT and I have seen a V6 where it blocked the oil pickup tube.
 

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Discussion Starter #13
First I check the valve cover. After that maybe I want to replace the oil return valves and check the CCT oil port. I want to find this problem so the car starts without the rattle.
Thanks for your help here. There is a lot of information here.
 

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Discussion Starter #14
Today I removed the valve cover. First cleaned most of the liquid gasket. Cams are both okay and the chain is has the right distance between cams. When I turned the crank CCT changed not much. When I moved it by hand it goes upwards, then I see some small scratches on the piston from the CCT. Is it possible that this is the problem that the piston from the CCT will not move.
 

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How much did you turn the crank? The CCT should rise and fall during the cycle, but I don't know how often, just that I always hear and see it when I crank a v6 by hand.
 

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Discussion Starter #16
More then a full turn, CCT rised a few times. Looks it stuck a little, when I pull it by hand it rised completely. Do you know how the CCT works? when the engine is running is the CCT up or down? Is there a spring inside the piston? How can I check if the CCT is the problem or the oil return valve?

Thanks for your help.
 

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The CCT has an internal spring, but it is oil pressure that keeps it tight and adjusts the pads up or down. Apart from that, I don't know. AndreasPassat might know more as he has rebuilt a few V6 engines.
 

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As Passat28V6 posted, I responded via PM.
Not to keep it a secret from the rust of the forum, this is a basic run down of what I sent him. This is a very abridged version of what I actually sent, but this is the crux of how the CCT works.



The tensioner doubles as the variable intake timing actuator. It has two plastic half-moons one on the top and one on the bottom. In between there's a piston pressurized by the oiling system (when car is running only) to keep the tension on the chain. When the car is shut off, the spring tension keeps the chain taught to keep the chain from jumping teeth on engine start-up. The whole tensioner moves up and down via a solenoid. When it's down there is more chain between the cams on the bottom, thus increasing intake valve timing. When it's up there is more chain between the top of the cams, so the intake timing is retarded. The VVT (variable valve timing) is only active between 1500-4200 RPM and only at WOT(wide open throttle), in that range increasing the intake valve timing causes an overlap with the exhaust valves and creates a suction effect where the leaving exhaust gases help to suck the intake mixture into the cylinder. At lower RPMs there is not enough air velocity for this to work, at higher RPMs the velocity is so great that some of the intake mixture would get sucked out into the exhaust.
(This is also why people who run superchargers disable the VVT, under boost it causes some of the intake boost to be lost to the exhaust).

I also went on to explain the other things we have learned over the years about dirt in the oil getting into the screen under the CCT, use of excessive gasket sealant, types of oil, the proper oil filter, and so on.

So hopefully we'll see some results in the near future.
 
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