greenquattro

I'm still trying to get the driver's side camshafts to line up on my dad's 1998 A4 2.8L AHA. I've counted and recounted the 16 rollers between the marks on the camshafts, and have tried this three times now with no luck. I'm hoping to reassemble again tonight but I can't get the intake cam to line up. Here are a few photos of the situation.

Any insights?

Intake (inner) camshaft:
<a href="http://www.flickr.com/photos/35072973@N03/4529756534/" title="IMG_7800 by terrencegrey, on Flickr"><img src="http://farm5.static.flickr.com/4064/4529756534_26ab81becc_b.jpg" width="683" height="1024" alt="IMG_7800" /></a>

Exhaust (outer) Camshaft:
<a href="http://www.flickr.com/photos/35072973@N03/4529756034/" title="IMG_7799 by terrencegrey, on Flickr"><img src="http://farm5.static.flickr.com/4036/4529756034_ff3c506e87_b.jpg" width="683" height="1024" alt="IMG_7799" /></a>

The whole shebang:
<a href="http://www.flickr.com/photos/35072973@N03/4529755660/" title="IMG_7794 by terrencegrey, on Flickr"><img src="http://farm5.static.flickr.com/4050/4529755660_ac746f485d_b.jpg" width="683" height="1024" alt="IMG_7794" /></a>

greenquattro

A little more information.

I had removed the camshafts and tensioner to replace the seals, and bank 2's chain fell off one of the sprockets, so I replaced it based on my very faint marks on the chain and sprockets, and got a CEL based on P1392 camshaft position sensor as well as cyl 4 and 5 misfires, so I removed and replaced the camshafts checking carefully for the 16 rollers. Then I got only the misfire codes on 4 and 5, and eventually 6 as well.

I just pulled the valve cover on bank 1 and the positioning seems the same, although I never affected the position and my marks were very true on this bank. Any reason both bank 1 and 2 would have the intake alignment marks off a bit? Why would this only produce misfire codes on bank 2?

4Driver4

IIRC, the number of links is different between the two banks.

greenquattro

Bentley shows 16 rollers for both banks, but at 16 I can't possibly get the camshafts to align. Does that mean the tensioners are bad?

4Driver4

No. It means that Bentley is wrong. It's about 14.5 or 15 on bank two. I just verified on two different heads, one from a AHA and one from an ATQ.

greenquattro

I just moved it to 14.5-15 rollers and the alignment looks perfect for bank 2, which was having trouble codes. Bank one is set at 16 rollers - and I never changed it - with the alignment off exactly the same as the pictures for bank 2 above. Should I realign bank 1 a couple fewer rollers, or leave it where its never shown trouble?

4Driver4

16 is correct for bank one. Leave it.

greenquattro

Firstly, thanks 4Driver4 for all your suggestions the last few days. I'm at a loss here and it's nice to have some help.

So I readjusted to 14.5, then to 15.5, and on both settings found 0 compression from bank 2 cylinders by turning the crank with a wrench. bank 1 shows 120 or so, but I know it will go higher if I run the starter.

The bank 2 cam tensioner seems to allow more slack in the chain at certain points in the rotation that the bank 1 tensioner. Could this be because oil pressure is too low without having run the engine? Or is the tensioner shot? I've been checking compression with the valve covers off, but bank 1 shows nice compression. Before I began this morning, with the valve covers on and the chain set at 16 rollers, I was getting 60 PSI in bank two by running the starter.

I still doubt that there is an issue with bent valves, I've been careful all along to test the setup by rotating the crank with no spark plugs to make sure there's no interference. What could cause the 0 compression readings?

4Driver4

There is no issue. Don't worry about the compression. It will come back when you start the car. At this point, you have the chains on right. Recheck the belt timing if you haven't already and start the car.

Edd W

Is there no markings on the cams or sprockets at all - the common form for German manufacturers is a small grind mark near on of the teeth, often on the back of the sprocket?