cam chain tensioner shoe - can it be improved?

[awolfinsheepsclothes]

It's a shame VAG don't recognize the common problems with there cars and sell just parts you need, at a reasonable price, as far as tell BMW Mercedes and Porsche seem to sell me what ever I need. This keeps the cars economical to repair, which keeps them on the road, and seems to help residual value, Which helps sales. I couldn't recommend any modern VAG product to anyone, and I don't. The breakers yards a littered with cars that could be repaired, Or engine & transmission problems that just shouldn't happen anymore. Soon we will all be driving KIA,s
Dave

[Goran]

Pad obsession continues with new car.
I caved in and ordered these pads. There is no way I was going to give Audi another £950 for 2 chain tensioner units when my old ones appear to be working just fine.

http://www.cs-parts.de/index.php?a=237

They are going into my car shortly, I plan to open up cam covers in around 1 years time to check how they are doing.

If anyone else is contemplating changing their pads, and is determined to have original Audi pads, there is a middle way. Ask your Audi dealer for part no. 058109217B or 058109217D, the price of each unit is £140 + Vat, if they can do you a discount it may be possible for around £300 for the pair. You could then try to sell the units on ebay to anyone who wants a discounted genuine unit but is happy to risk aftermarket pads.

Picture of cs-parts.de pads

[notorious]

Goran, I'm following this thread with interest. When I first open cam covers I will look at pads of course and will be changing preventively.

[Goran]

Sergey, please take pictures of your old pads. I have my old pads from the previous S8, I will post pictures of them. Taken out at around 112k miles in 2012.

[SilverS8]

This is def a interesting thread. My car has 149k Miles on it and if these wear out and cause engine failure they need to be checked

So you bought yours from cs-parts? and 2 sets are needed(4 pcs?)

Just did the fuel pump change so might just as well go ahead and do this also

[Goran]

In the link above it was 5 euros per pad, you need to order 4, so 20euros total. If you plan to do it yourself best to order the combo with special tool 3366 and gaskets.

Its a worrying issue. Some cars have made it beyond 200k miles with no apparent problems.
It doesn't seem to be an epidemic, with A8's at least (lots more failures on web with A4's)
I'm not sure what the primary cause is, heat? oil? heat and oil? mileage or simply length of time in engine, ie, degradation with age.

Its definitely worthwhile at least opening the cam covers, to change old gaskets anyway, and check the tensioners, if they look very worn or close to cracking definitely change them.

Here is Sam's guide on quattroworld when he took out his. MRC will be taking out mine using this intake-cam-only method to save on labour.

http://forums.quattroworld.com/a8/msgs/55496.phtml

I have thought about this a lot. I am really curious if there is a fiddly, but possible way to change them out without taking out the cams at all.
At this stage it is purely theory as I have not had access to a open cam assembly to test it out. I will try to describe what I was hoping to try.
Once you have the cam covers off (following Audi procedure up to this point):

1) depress edge of tensioner pad mounting platform enough to be able to slip the top pad off without special tool 3366

2) slip a piece of card between metal pad mounting platform (on top of tensioner piston) so that chain is not resting on metal.

3) using special tool 3366 depress the tensioner piston. This should allow extra slack in chain compared to Audi procedure which requires tool 3366 to press down on the old plastic pad still in place.

4) rotate intake cam to move chain slack to the bottom of the chain. Secure with rubber band or something. Chain tensioner still installed.

5) using a length of sticky tape (electrical tape), get the tape to slide between the chain and bottom pad. This part is theoretical there may not be enough space to do this.

6) with tape stuck on the bottom pad, use a thin plastic or wooden rod (you dont want to scrape metal to metal in there) to pry off the bottom pad. I have tried this with a removed tensioner it is easy. It will work with a installed tensioner only if there is enough room for the plastic rod to reach it.

7) carefully pull out bottom pad using the sticky tape stuck to it.

8) unbolt tensioner unit and lift just enough to scrape off old tensioner gasket and install new one. bolt chain tensioner back in place

9) cut a long lenght of electircal tape and stick it onto the face of one of the new pads.

10) carefully manouver new pad using the tape down to the bottom of the chain tensioner. This may not be possible. Even if it is possible it is likely to be very fiddly, and may not save any time compared to unbolting and removing the intake cam. This was a method designed for someone not competent to mess with a cam (ie, me).
I wanted to try this because I was more scared of unbolting the intake cam and getting the torques or timing wrong when bolting it back in.

11) with pad in place pull with tape until it clicks securely into position. remove tape.

12) remove tool 3366. Press piston by hand so you can fit a new pad on top of tensioner. Job done.

Even if this method doesn't work, its a free try, in other words you just carry on with the proven procedure of removing the intake cam.
If you are confident taking cams out, and getting the torques of cam caps and timing right, this is a pointless procedure.

I have attached the original ElsaWin procedure for both right and left tensioner/adjuster unit. This is for a 2001 S8 AVP engine. If anyone wants procedures for other engines please ask I will upload them.

If your engine is Pre-Facelift, relax, you are safe

[Goran]

I have had my pads changed at MRC. Surprisingly it only took them 4 hours, for both banks, I was expecting it to take longer considering the complexity.
So total cost was 4 x £68 x 1.2 = £326 plus 20 euro for 4 pads.

Here are some pictures, these pads taken out at 120k look a little better than from my other S8, those were pitted at the top too and one had a large crack developing.

I am a engine hypochondriac, so for me this preventative maintenance was worth it for the peace of mind.

I would still like to try removing the pads without unbolting cams. If someone has a old or damaged head, either side, I dont mind driving over to try this procedure. I have 2 old tensioner units and the tensioner tool.

[jza8]

I bought 4 pads and the compression tool from cs-parts.de, but never got to fit them. I someone feels brave enough to try - £15 posted
http://www.cs-parts.de/index.php?a=709
says they fit 2,4 30V / 2,7T 30V / 2,8 30V / 3,7 40V / 4,2 40V

[Goran]

Just as an update, my engine hasn't blown up yet with those pads from cs-parts.
I hope I haven't just jinxed myself

[MikkiJayne]

So MRC didn't change the chains or the cam cap bolts then? Etka says to replace the bolts, but 52 of them is a fair overhead.

I like the idea of changing the pads in place. I might give that a shot on my spare head just out of interest. Leaving the exhaust cam in place is a bonus time-wise and also for oil seals etc.