yeah I always figures this…
bad oil, gummed passages
gummed passages, low pressure at startup
low startup pressure, low chain tension
low chain tension, chain smacks guide
chain smacks guide, chain rattle
chain keeps smacking guide, guide breaks
guide breaks… well fuck your life
interested to see what the other cause/s could be
I’m gonna take that guess and reverse it bad guide, guide fails then intern causing tensioner to fail!
In for this, and nice theory beem!
Always good stuff guys. Ill have to get more into this later. Here are a few pictures to show you what were working with.
Here is the tensioner 1 of 4. Still in its spot on the motor
http://audirevolution.net/addons/albums/images/379849605.jpg
I know you can’t see all of them but you can see the chain layout and you can still see at least 1 tensioner
http://audirevolution.net/addons/albums/images/853321513.jpg
Here is a little peak on what it looks like when you break it apart
This starts the “chain” of why the tensioner fails. More to come.
http://audirevolution.net/addons/albums/images/58878917.jpg
a little more apart.
http://audirevolution.net/addons/albums/images/730278402.jpg
now this is what the receiver site looks like
http://audirevolution.net/addons/albums/images/868203854.jpg
hmm that garage looks familiar, any chance that engine block has a hole in the passenger side? 
i have a vast recollection of this engine 
Back to the tensioners.
what were looking at here is the back of the tensioners. You can see there is a oil port on them. Oil comes up from the pan to pressurize these. You can see how small the ports are on these.
http://audirevolution.net/addons/albums/images/483358255.jpg
The oil goes into the block, then into the port on the tensioner and threw this orifice
http://audirevolution.net/addons/albums/images/752554489.jpg
We saw this before in the picture above.
http://audirevolution.net/addons/albums/images/868203854.jpg
fingerbanging a 4.2.
NSFW!
Good stuff, wonder if this is going on with my car. lol
Lets do a compression test on it. That should get more information. I still think your car is fine-ish lol.
I do need a compression test, just have to find the time and do it.
It only took me about 45min to an hour. Really wasn’t bad. I did min by just jumping the starter rather then pulling the fuses and cranking through the ignition. I only did a dry test though, but going back I’d really like to do a leakdown test as well. It’d defenitely be worth the time while you’re in there.
Someone needs to make a compression test DIY/FAQ. Such an important part in determining the health of these motors
Great point and great idea. I think the biggest issue for real non mechanic guys will be getting the tools to do it. Then just making sure its done right, as just like any test sometimes people can make sure to do a test and fool themselves into the data they want to see.
Yea, I found a bit of conflicting info out there when I did my compression test, it would be nice to have one clear diy on it though. Tool wise it didn’t seem that bad really (besides needing a compression tester). For me, all I did was disconnect the battery, pull the coil packs and then all the spark plugs (obviously keeping them numbered and in order for reference), then made sure throttle plate was partially open, and I just “jump started” the started motor by making a little set of wires (plug is behind the airfilter next to the O2 sensor plug, for the 4.2 S4 at least) and let it cycle through a couple of times once the compression tester was screwed into the right cylinder. It prevented needing to pull fuses or have someone crank the car at the same time.
Hopefully this was all okay, Halik kinda helped me through it as he had just posted on AZ that he had done a compression test on his new motor. I should have also done a wet/leakdown test, but I only did a dry test at the time.
Perhaps I should start a new thread, but here goes anyway. Not being a mechanic, it’s unlikely I’ll need to know why they fail, the question is what to do after it has?
3 weeks ago I had my 05.5 S4 Avant in to have the Zenon lights replaced for the dreaded flickering and dipped issue. During that servicing I had my car thoroughly inspected and diags run. Everything was clean. 2 weeks later my car is parked at the garage with 2 cylinders with 0 compression with a suspected tensioner failure. My Audi dealer wants a $5K retainer just to look at how bad it is?
My car has seen a very easy life since I have owned it and I have a hard time understanding how a perfomance motor suffers such catastrophic failure and I’m suprised people are not more frustrated with it?
Where are you located? I’d go private/independant before going to the dealer for a job like that.
Maybe the guys here can help you out once they know where you are. WORST case scenario, you buy a used motor and replace your existing one…then look at whether or not the original one can be repaired etc and sold to offset your costs. The dealer on the other hand will tell you about $15,000 for a new motor etc. That’s just ludicrous when you can find a used one for a couple grand to 3-4.
I did a semi DIY compression test in my “RS4 smoke issues” thread. I can do a cleaner version with the pics I have and take people through the step by step process. Maddog covered the job 90% already, its really not bad at all. THe compression tester can be had for $100 or less…or more depending on brand etc. Took me about an hour, taking my time.