kelisko

There are two of them. My thread at the link below may be useful locating the one you are missing.

Here: https://www.audiworld.com/forums/a6-.../#post25425755

thedoge

Thanks for the pic. I went back out and finally found the other ground wire. I also found where the large cable connector in this same area was not plugged in all of the way. After taking care of these two items the codes went away and the car is running reasonably well. I have a high negative number for the passengers side so either I did an excellent job or more than likely I am going to have to go back in and redo this side as I may have not pretensioned correctly. What is strange is that I hear a bit of rattling from the drivers side but those numbers show to be good. Oh joy.

thedoge

I dug back into the passenger side to redo the pretensioning of the chain. I had removed the chain tensioner and as suggested earlier in the thread I removed the cylinder and while holding in the relief valve on the back pushed the piston back to push out the oil in the cylinder. I put the cylinder back in the tensioner and as I was compressing the arm back to put in the holding pin I saw oil leaking out around the cylinder seal. Is this normal while compressing the cylinder? I imagine what little oil was left in the cylinder had to have some where to go. I just do not want to put it back together to find out I have a bad cylinder.

An edit for this post. In retrospect I am wondering if bleeding out the fluid from the piston was a good idea. This morning when I went to put it back together I found where the piston would not pop out. I guess this would make sense since I removed all of the fluid from the chamber that would provide the pressure. Not sure if I install it if the oil pressure will fill the chamber back up and allow the piston to move. Going to check with the local dealership to see if they have one of these in stock and bite the bullet and pay dealership rates for the part if they have it.

Found out the dealer does not stock this part. Wondering if I should use the piston from the old unit. The numbers from this bank were not that bad. Really want to get completed this weekend.

thedoge

A question about the tensioner pistons for anyone who had to recompress the arm. When I tried to do this the piston on the new unit compressed all of the way down and would not come back out. I tested the 2 old pistons and they did the same but did not compress as much as the new one. Did you find the same with yours and then when installed and oil pumping through then the extended back to the normal position?
Thanks

hrc4u

Here is info on how to reset the tensioners if you haven't seen it 👍
https://m.youtube.com/watch?v=RX-
C4rF_qWs&feature=youtu.be

Cheers! /H

thedoge

Thanks for the video link. I have been through this thread numerous times and have not seen this.

thedoge

OK, this is my third time going through this. I keep having negative numbers come up for bank 1. I wanted to see if someone who has done this successfully can review the steps that I am taking below to confirm that I am going about this correctly. Obviously I am doing something wrong and thought by making my own step by step process that will help to figure out what is going on. I am skipping ahead to where I have all of the covers removed, new tensioners installed and working only on bank 1 (passenger side). Bank 2 has good numbers.

1. Rotate engine in a clockwise direction until the cam lock bolts can be screwed all of the way down on both banks by hand tightening only. Tighten further with socket.
2. Timing mark on harmonic balancer should line up with seam between block and upper oil pan.
3. Insert crankshaft locking bolt. ( A real pain)
4. Once crankshaft locking bolt is in place attempt to move crankshaft clockwise or counter clockwise a little to assure crankshaft is secure.
5. Loosen cam bolts
6. Use cam adjuster holding tool on the exhaust adjuster (bottom one) and with mild force attempt to rotate adjuster in a clockwise direction to move any slack in the chain toward the cam.
7. While using the cam holding tool tighten each cam bolt to 30 lbs.
8. Same as #7 but tighten to 60 lbs.
9. Same as #8 but tighten to 90 lbs.
10. Same as #9 and turn each bolt 90 degrees further.
11. Remove cam locks and crankshaft lock.
12. Rotate engine 720 degrees in a clockwise direction.
13. Install cam locks and crankshaft lock. Everything should go together per steps 1-4 above
14. If step 13 goes well then remove cam locks, crankshaft lock and put everything back together.

I appreciate any help that can be given. I need to get this wrapped up to get to my list of other projects.
Thanks

Dan

Sverige

It looks like your process is basically ok, but a couple of points. First step 4 I would change to “attempt to move crank pulley while trying to screw crank pin in further”. You may find that the crank pin bottoms out as though it’s in place, but then turning the crank pulley an imperceptible amount allows the pin to screw down even further. That was the only way I found the true “zero” point for the crank, the position where the cams with their cam locks secured must be in time with to give zero numbers on block 93.

To understand the pretensioning, It helps to keep in mind the complete system of chains which connect the crank to the cams. Photo below. The silver pulley is the crank and it will turn anti clockwise as pictured, because the engine turns clockwise and we are looking at the back of it. All the pretensioning is to accomplish is that when that crank turns, it draws the cams directly via the chain system, with no chain slack to be taken up first. So we pretension with the cam adjusters before they are screwed down, to effectively pull a little against the locked crank gear. Thinking of it this way and looking at the photo helps be sure which cam you’re pulling on to pretension and in which direction.

When the upper chain tensioners fail and there’s slack sitting in the upper chains behind the cams (at the tensioner location) the cams tend to over advance towards the crank, so intake and exhaust are firing a little early and you get positive block 93 numbers. You have the reverse situation on bank 1, negative numbers meaning your cams are too retarded (not to be mean to your cams!). So assuming your crank pin really was fully screwed down with crank at zero at your previous attempt, I’m going to say you didn’t pretension enough on bank 1, so when you screwed down your cam adjusters you effectively have a little bit too much chain length on that path from the sliver crank pulley to the bank 1 cams.

You already mentioned you’ll be putting cam locks on both banks, and this is good because the other thing clear from looking at the photo is that as the chain system is connected to both banks, changing the chain tension on one bank has the potential to drag the block 93 values for the other bank off target. When you get the cam cover removed from bank 1, check the chain tension in the three sections you can get your hands to (before intake cam, between intake and exhaust cams, between exhaust cam and tensioner). I’m betting you might feel less tension in the first of those three, which corresponds to a tiny delay when the crank rotates before the bank 1 cams begin to rotate.



3.2 FSI engine, chain system to rear. Silver crank gear rotates anti-clockwise as viewed

thedoge

Sverige,
Thank you for the information. Not to be dense but can you clarify an item on the chain tensioning? In viewing the Edge Motors video it appears that he is moving the drivers side intake adjuster in a clockwise direction as you sit in the vehicle which would move any slack toward the middle of the engine. On the passenger side would not the intake tensioner need to be rotated counter clockwise as you sit in the vehicle in order to move the slack toward the middle of the engine as well?
Thanks

Sverige

No. On bank 2, driver’s side, turning the intake cam clockwise draws the chain from the crank and takes any slack towards the tensioner. On the other side, bank 1, the cams should again rotate clockwise so that you are pulling the chain against the locked crank and any slack ends up on the side of the cams with the tensioner (which then takes this slack away when it gets pumped up). This is not towards the centre of the engine on bank 1, even though it is on bank 2.