[mattceq]

Replacing cam chain tensioner on 2000 Passat v6, drivers side. Car ran good, no codes but loud cam chain noise. Plastic worn, I replaced plastic pads and re-installed without taking out the exhaust cam. Before I removed, I turned engine over by hand and chain was very loose and popping, to line up marks. Set at TDC (mark on crank shaft pulley) and exhaust cam lined up mark, intake did not line up. Counted 15 links between. I marked cams and chain at 16 links. I thought chain must have slipped a tooth when I was turning the motor over. When I finally got the tensioner and intake cam in place, timing looked good, with intake cam lining up pretty much on the mark (exhaust cam not touched - held by timing belt). Turning engine over by hand I had some resistance so I turned it back, checked marks, looked good to me. I applied lots of oil to all the cam lobes and timing chain, and slight resistance but then felt much better (praying I did not damage any valves). Counted 16 links - put back together. Started car, lots of rattling noise and check engine light. codes - cam timing off. Took valve cover off, if I line up the cams to the marks - 16 links, but if I set at TDC, exhaust (and intake) cams are not on the mark! It's like the exhaust cam is out of time! How could this happen? The timing belt is so tight, I cannot see how this could happen? I probably have bent valves. What is my next step??

 

[Tomvw]

Remove all spark plugs and leave out until the timing etc is right.

If you turned it backwards against resistance, the TB probably jumped teeth.

With the cams aligned to the timing marks, how many TB teeth is the crank from TDC ? (I assume it is before TDC)
Are both heads correctly timed to each other ?

 

[mattceq]

Remove all spark plugs and leave out until the timing etc is right.

If you turned it backwards against resistance, the TB probably jumped teeth.

With the cams aligned to the timing marks, how many TB teeth is the crank from TDC ? (I assume it is before TDC)
Are both heads correctly timed to each other ?

Looks like 1 tooth on the cams (driver side). Should I remove the passenger side valve cover? This is one tooth past marks on cam when turning the crank clockwise to line up the mark on the crank. Not sure how many TB teeth. How do I check?

 

[Tomvw]

If the CCT pads were worn on the driver side, they probably should be replaced on the passenger side too.

If you don't know that the Timing Belt and associated parts has been replaced within the last 7 years,
and it has done less than 80,000 miles, you should replace them now.
When was the TB changed ?

 

[mattceq]

Timing belt was changed at 93,000 mi. and I replaced the cam chain tensioner on the passenger side last year. Car has 136,000 mi. now. I not sure what I did wrong. I did turn the motor counter-clockwise a some when things didn't seem right. I didn't want to go 360 deg. more. Just now, I had to turn the crank about maybe 40 deg. to get the cams on the marks. Like I said I never removed the exhaust cam (or timing belt). I still count 16 links between the cams. Both banks look timed to each other. The belt must have moved on the crank. Do you think there is any chance the valves are not damaged? Otherwise, I would think my only choice is to scrap the car.

 

[Tomvw]

The best way to check for bent valves is to correct the timing then do a compression test.

Turn the crank at least one turn (clockwise only) to line up cam timing and fit cam locking bar.
Remove TB and turn crank to TDC and fit crank lock pin, fit timing belt.

NOTE: Do not continue turning crank if excessive resistance is met.

 

[mattceq]

That's what I was thinking. I will have to put the car in service position and rent or buy the locking bar, etc. Thanks for the advice.