[Biturbos4] I think I really did it this time (timing belt gonewrong) HELP!

Tue Nov 16 18:12:47 EST 2004

Possibly this could be added to the AW tech section or the S4 resource page.

David Kavanagh <audiguy at gmail.com> wrote:I'm gonna print this out and keep it on hand for when I do my 2.7t belt! 
Thanks, Keman!!!

On Mon, 15 Nov 2004 15:37:45 -0500 (EST), Keman wrote:
> Ohhh boy. Hehe. Oh boy. Where do I start.
> 
> If the engine idles fine the noise you're hearing isn't the pistons hitting
> the valves. Once that happens it won't idle worth crap and you might as well
> go out and get real drunk before getting the estimate bill. Both cylinder
> heads to be removed, rebuilt, and/or replaced and reinstalled ... I see
> $7000 easy ... why so much? Step one: remove engine. Step 2. Remove turbos.
> Step 3. Remove cylinder heads. ... you get the idea.
> 
> So. Lets hope that didn't happen.
> 
> Ok. First off, the teeth on the timing belt are meaningless on the 2.8/2.7L
> engine. Audi knows that belts vary slightly from maker to maker, so why let
> the teeth limit the calibration? The cogs on the cam are infinitely
> adjustable in relation to the camshafts actual position. Once you put the
> new belt on, you SYNC them to be exactly where they need to be.
> 
> The cam lock tool (the big huge bar) actually /positions/ the camshafts in
> relation to the cam cogs. The cogs are not keyed. They can sit on the
> camshaft in any position, but the "washer" with two holes in it which you
> keep parallel to the ground? Those /always/ are in sync with the cam
> since -they- are notched. Yes, FRICTION holds the cam to the cam cog. No
> kidding here. It's always been sufficient and noone I know has seen one slip
> so it's a good design and don't worry about it.
> 
> First things first-- time to get the cams in sync.
> 
> 1. Roughly line up the crank/cams so that the smaller holes on the cam
> washers are facing towards each other (towards the center of the engine) and
> the TDC mark on the crank pulley is at the notch in the cam belt cover.
> 
> 2. Remove the crankshaft position sensor down on the front drivers side of
> the block and insert the special audi crankshaft lock tool (purchaseable at
> your audi dealer). As it threads into the hole the crank will get budged a
> little and is now exactly where it needs to be and cannot move.
> 
> 3. Take the belt off. I know, this isn't what you wanna do but you gotta.
> 
> 4. Take off the bolts that hold the cam cogs on to the cams.
> 
> 5. Now, using VAG tool xxxx (or your favorite hammer) give the cam cog
> washer (that thing with the holes in it under the cam bolt) a few good
> whacks. Act like you're trying to bend it towards the engine. One sharp one
> should break it free and it will fall onto the ground into the bucket of
> used oil you left there on accident from earleir. Don't worry about it now,
> we'll fish it out later. Next put a rag over the cam cog and give it a good
> whack on the forward facing edge. It too will fall off. If your driveway is
> on a hill make sure to chase after it before it ends up on the street.
> Repeat on the other cam.
> 
> 6. Lay the cam cogs back onto the cams and the washer/bolts back on, and
> tighten the bolts by hand down to the point where the cam cog can rotate
> freely from the camshaft with only minor interferance. The cam is tapered.
> The cog should be sitting on the cam rather loosely right now for this to
> occur but tight enough that it can't rock much back and forth.
> 
> 7. Take the special audi VAG camshaft sync bar tool (or your favorite
> substitution) and slide it into the holes of the "washer" that's under each
> cam bolt. THIS SYNCS THE CAMSHAFT-- it is critical that it locks into the
> camshafts perfectly. It's laying across the engine essentially 'connecting'
> the two camshafts to one another and resting parallel to the ground. You
> will have to slightly turn one cam to get the bar to stick into all four
> holes perfectly and in doing so the cams are now perfectly in sync, and the
> crankshaft is still locked and exactly where you want it.
> 
> 8. Put the belt back on with this bar still in place. Let the cam cogs
> rotate as they need to during this process. Remember, they are capable of
> turning, the cams cannot.
> 
> 9. Release the tensioner. Give the belt a few tugs, the cogs will turn
> slightly to let the tension complete.
> 
> *** A note about the hydraulic tensioner- compress it using a vice NO FASTER
> than 5 minutes. That is you will sit there slowly turning the vice at
> sufficient speed that it takes 5 minutes to fully compress the piston. Any
> faster and it ruptures internally and you've toasted your timing belt
> tensioner. Once it's fully compressed stick a hex key or drill bit through
> the holes to get it to lock like you would put a pin into a grenade.
> 
> 10. Torque the cam bolts down to spec. 45 ft/lbs if memory serves. Do not
> use loc-tite.
> 
> 11. Remove the cam position bar and the crankshaft lock tool. Put the CPS
> back in and dress the engine all back up.
> 
> 12. Poof. Yer done. Drink german beer- I suggest Gordon Beirsch Pilsner. :)
> 
> - Keman
> 
> > Yeah, I have to concur with Igor, Matt. That noise is a pretty
> > unmistakable clanking. I wouldn't reccomend messing with it for another
> > instant and take it straight to a paid mechanic. If you're religious,
> pray.
> > Aaron LaPointe
> > 01 Nogaro $4
> >
> > MattOVR6 at aol.com wrote:
> >
> > >So I got ambitious today and decided it was time to change the timing
> belt on the 00 S4. I got it all apart, and it went fairly smoothly.
> > >
> > >I didn't have the cam lock tool, but I fabricated a makeshift one out of
> a 2" metal strap that I thought would do the job. I had it slip off as I
> was removing the belt, and the passenger side cam sprocket and cam popped
> and went to the left. I had marked it before on both, so I brought it back
> to that point and reattached my camlock thing. When I started the job, I
> rotated the crankshaft to the point where the holes in the cam sprocket
> flange were parallel to the ground. As I was putting it all back together,
> and checked my marks, and they were just a slight bit off, but both of them
> were, so I assumed that it may have turned a bit. But the toothed belt
> would not let me change that at all.
> > >
> > >So I put it all back together, and it idles fine, and during slow rev
> climbing is fine as well. But if I stab the throttle, I'm getting an awful
> clacking sound that sounds like it's coming from the middle of the engine
> somewhere. I can't tell whether it's due to timing being slightly off, or
> what else it might be.
> > >
> > >I took it all back apart to make sure there weren't any tools in there or
> things that I had missed, but it checked out fine.
> > >
> > >Is there a way that I can check the timing, or find the TDC mark and
> index the cams? I've heard that Audi cars do not have any sort of indexing
> mark on them, but can't verify that.
> > >
> > >I need your help, Audi Gurus!
> > >
> > >Thank you,
> > >Matt O.
> > >2000 Audi S4 (74,000 miles)
> > >1995 Turbo Jetta 3.0 VR6
> > >
> > >p.s. Spare the lecture about how I should have bought the $180 Audi
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> 

-- 
'00 A6 biturbo 6-speed
'01 allroad 6-speed
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