2001 4.2 how to align cams on cam tensioner chain?
 

I have a 2001 A6 4.2 AWN engine. Need to know how to align the cams in relation to one another in regards to the cam tensioner chain. I see small arrows on the cam caps adjacent to the cam tensioner, but no marks on the cams. I took off the cam tensioner to change the gasket and I think I may have got them out of whack. Can someone explain? Thanks in advance.

count cam rollers between cams
 

I assume you don't have the Bentley manual, nor marked the cams/chains before removal? You do have the cam locking bar, right? And the chain tensioner tool, 3366?

The marks on cams are little square recesses between chain and cam cap, marked with a yellow "x" in the pic. You have look down in the recess with a flashlight, easy to miss.

I marked everything BEFORE disassembly, and took pics, just in case.

These are pics with cams in proper position, with cam locking bar in place, on a 2002 4.2 AWN. Bentley manual says 16 rollers, but I count 15 on left bank, and 15.5 on right bank.

You will notice that cam tensioner is a little more compressed on left bank, than it is on right bank. Left exhaust cam pulls chain to intake cam over the top of tensioner compressing it from top, but right exhaust cam pulls chain to intake cam on downside of tensioner, thus chain is tight on down side. However, both intake and exhaust cam marks (yellow x's) ARE lined up with bearing caps in these pics.

I'm finding conflicting info on the web on this...

I'm at TDC now on right (passenger) head, I'm assuming this mark on the cam (pointing to it with screwdriver) is the mark that has to align with arrow on cam cap. If I align the mark on exhaust cam with the arrow on cap, then align the mark on intake cam with cap arrow there are 15 links on the chain between them. Somewhere someone has said that Audi manual calls for 15 on left (driver) and 16 on right. Anyone really know???


http://i95.photobucket.com/albums/l1...s/DSC04721.jpg

http://i95.photobucket.com/albums/l1...s/DSC04720.jpg

http://i95.photobucket.com/albums/l1...s/DSC04722.jpg

Attachment 79574

You will note that on right bank, rollers do not align exactly with cam marks. My 15.5 rollers is what Bentley may be calling 16 rollers (right bank). I just call it as I see it, and that's how mine was and still is.

But, for left bank, it is certainly NOT 16 rollers, I show 15.

Thanks for your reply socal!

Yes I have the cam bar with the insert screwed into the side of the block getting me to TDC. No I didn't use the cam tensioner tool, I used a fat zip tie wrapped around to compress the tensioner and it worked fine.

Also, maybe I'm using the wrong terminology with regards to the links of the chain. I count 15 links on your right head picture. Anyway, am I right to think the real goal is to have the marks on both cams line up with both marks on the caps at TDC?

By the way, I have this bentley manual, which is completely useless on 99% of the projects I've tackled. Is there another bentley manual that is more useful? Thanks again!

http://i95.photobucket.com/albums/l1...s/DSC04728.jpg

Yes. My yellow marks are where the cam alignment mark is with bearing cap, and it's really 15.5 on my pic, I think. I think if you tried to get right bank to 15 rollers, you'd be off. My pics are from an unmolested engine that never had it's valve covers off, until I cracked 'em.
You have the Service Manual. There is a manual called Bentley (Ebahn) Repair Manual, and it's on CD. It has errors too, but what can you do. It covers technical repair in all areas. Go to Bentley Publishers to find title, some retailers have it for cheaper.

Here's the section on cam chain adjuster R&R on 4.2 as an example
http://www.csupomona.edu/~bvnorum/eb..._adjusters.pdf