RS6 Timing belt replacement DIY

[Mɐʇʇ]

Not sure if serious....

Anyone know what OE is?

[Shoppinit]

Lol. Must have been a pre-coffee post.

[Mɐʇʇ]

11:23pm last night.
("The workshop" runs from about 10pm to midnight, once the Mrs is in bed)

[Shoppinit]

Nice photo.

Out of interest, what do you do about the AC gas?

[Mɐʇʇ]

Just take it to a local place that's got the correct rig to vacuum, recharge, and add the correct thimbleful of oil.

[Banana man]

I know mines just an S but I’m pretty sure you can do the same and just lay the carrier down on a milk crate or something similar, keeping the A/C and oil cooler lines connected.

I didn’t know about the second tensioner requiring the VAG tool, which for reference is very cheap from the dealers or TPS if you can get someone to order it, so with the car in bits I tried to guess it which didn’t go very well, timing ran but it was miles out 14 degrees iirc, I got the tool and used it with the carrier in place as on a S6 its a lot easier, I used a 5mm Allen key to measure the gap, but it was still a faff.

I found the easiest solution third time round and it was to set both tensioners at the right point, then nip the cam sprockets up and turn the engine over a good few times until the belt has settled, double check your 5mm gap and leave both tensioners still and don’t disturb the belt, I used the locking bar to hold the cam still and undo the bolts then hold the puller still whilst popping the sprockets off the cams, then reset the cam timing with the bar using it to turn the cams if necessary then slot the bar in and tighten the bolts back up.

I got it bang on “0” this time and it was a lot less faff.

Why they used the two tensioners is a pain as the 2.7tt engine is practically the same layout with only 1 tensioner and it’s a lot easier to get it first time round.

[Mɐʇʇ]

Yeah. I did the same. Set it all up, spin it over a couple of times and then retweak the sprockets so the bar is super slick with the TDC bung in position.

[Classik]

My mechanic, despite being (or because he is) an experienced one and also an RS6 C5 owner, keeps telling me he doesn't need the specific tools you mentioned in your tutorial (lock bar + T40009 nut). Admittedly timing of the car is within limits (-6/+6) as measured on the VCDS, but I'm dreaming of a nice 0. His point is that except by luck you can't achieve this with an ageing engine.. Since we are in the middle of the big engine out job, I asked him to change all 3 timing sensors so it may end up he's been right, and the sensors could be a bit off (got a similar issue on my former S6).

Yet I still need to be convinced the job can be done without those tools. Comments?

[Shoppinit]

None of this makes any sense to me.

How do you align the cams with each other and the crank if you don't physically link them? The left cam is under tension and when you release the belt it moves a significant amount - I mean engine breaking amounts. The only way I can see that it could be done would be to mark the old belt with Tippex, transfer to new belt and then realign the cam sprockets to the marks on the new belt. But we know this doesn't work on the Audi V8. It's been proved over and over. It kinda works on a 4 pot and I've done it in the past.

The simple fact is that unless you align the cams and crank first then fit the belt and equalise the tension by loosening the cam sprockets then the timing will be a bit out. Maybe that doesn't worry him since it's not his car.

You could probably get away without the T40009 socket, but why would you? You'd have to fabricate something or do your head in to adjust the tension. It's a £10 tool.

I don't buy the argument that "you can't achieve this with an ageing engine". Why? What is it about the engine that means you can't get the timing right? Engine wear is measured in microns. There's no reason you couldn't get the timing perfect even on an old back of nails if you are replacing all the pulleys and tensioners, which you obviously are. You're even replacing the sensors. That's some serious OCD <beep> right there, and I thought I was bad.

Hearing this from someone about to work on my car would give me serious misgivings.

[Classik]

Well he did it twice like this on his own car, but obviously I take your advice and warnings very seriously. I'll have a call with him today.

[Shoppinit]

Like what? Tippex style?

[IchBautAuto]

It might be reasonable to say that someone who does this every day for a living can get it within 12 degrees. That is "OK" but not optimal. I have 4 Audi, an A4, 2 x 2.7tt and a V8 and that's all the timing belts I do, so an average of 1 per year using 3 different techniques. I wouldn't even consider doing it without a crank pin and the cam bar, albeit I reckon I might be able to get a running tune without. Fact is that when the pins are in, the marks don't usually line up so using the marks instantly introduces an error.

My guess is that you have a confident mechanic who has a less than OCD attitude to accuracy. You wouldn't employ him in a race garage if you wanted to win, would you. That said, if you didn't have access to VCDS or whatever, you wouldn't even know if he did a great job or not. For the average Joe, if the car runs evenly with no fault lights its all good. We are in part a hostage to our own enthusiasm.

[Classik]

Like what? Tippex style?

No, but again I'm just repeating things that are above my head.
From what I remotely understood, if the cam chain tensioners have been properly installed, the alignment is foolproof.

My guess is that you have a confident mechanic who has a less than OCD attitude to accuracy. You wouldn't employ him in a race garage if you wanted to win, would you. That said, if you didn't have access to VCDS or whatever, you wouldn't even know if he did a great job or not. For the average Joe, if the car runs evenly with no fault lights its all good. We are in part a hostage to our own enthusiasm.

Can't say if this applies in this case, but that's a good point. It's just that, like everyone here, I'd like to get this perfect otherwise I'd be driving a Peugeot

[Shoppinit]

Like what? Tippex style?

No, but again I'm just repeating things that are above my head.
From what I remotely understood, if the cam chain tensioners have been properly installed, the alignment is foolproof.

What do the cam chains have to do with the cam belt timing adjustment? He shouldn't be anywhere near the chains if he's just doing the belt.

Is there some confusion here about what he / you thinks is going to be happening?

The cam belt sprockets are on tapered shafts with no key way and are infinitely variable. This means that either a) he doesn't know this or b) he has no intention of unbolting the sprockets from their current position, in which case you will inherit any timing issues and maybe some new ones.

There is an established Audi procedure for doing the timing of the belt and while it's cumbersome it is logical and clear. Anything less than using the proper tools and doing it by the book seems like a shortcut to me. I am all for clever short cuts that get the same result, but in this case I don't believe you *can* get the same result. Except by accident.

[Classik]

Not trying to defend him, but don't judge the guy just on what I thought I understood, I may well be talking nonsense for a good part.... But I'll make sure to pass the message, and I think he can read English..