Cam chain tensioner tool broken inside head

[danspach]

Nothing like the front. No cracks but that was pretty unsettling to see. On the JHM site now looking at the lightweight version. I see the stock part is NLA. Any other options aside from JHM?

[danspach]

So I finally got the cams and tensioner out (another cam cap bolt almost stripped out).



Sitting in the bench I finally had access to the offending bolt that’s snapped off the junky Blauparts tool. Turned the bolt remains out and slid the tensioner out.



This is when I discovered when the bolt bottomed out inside of the head, it actually pressed the bottom tensioner rail up and bent it.



I’ll admit the only way to have correctly gotten this out was to do a timing belt service (which has led to a lot of improvement on this car) but the fact that their tool ruined a factory tensioner is “disappointing”.

Anyone have a stock tensioner laying around they be willing to sell?

I have new pads and really only need the bottom part.

[rollerton]

A little bit late, but where you wee a while back -FWIW you can really just pull the timing belt off and remove all the cams out of both heads and then set it all to TDC and do the timing service from scratch. Once the cams are out, all the valves are closed and you can rotate the crank around with no risk. From that point it's just a matter of doing your tensioner service and putting the cams properly set with the chains/tooth count set to spec.
From my experience the ONLY cam you can remove with the timing belt still on is the passenger side intake. And then it can be a hassle, but with some care/ patience you can do it. I think I still have a passenger side chain tensioner I saved from my old S6, you need it just let me know- I think it's a passenger side?. But that bend *should* be fixable?

Looks like you're on the road to assembling, but when something goes wrong on these jobs....it REALLY goes wrong huh? SHARP drill bits for those broken bolts, it's all just nuts and bolts but I swear it seems like these cars know exactly how to screw you.

[danspach]

Hi Rollerton!


That's a really good point about the cams and at this point I will be taking the passenger side cams out too to do the tensioner pads and gaskets. (I'll definitely be using the 034 tool to compress that tensioner.)


Thanks for the perspective. This has devolved from what was initially a valve cover gasket job so I've found myself diving down one rabbit hole after another. Can't decide if it's more "death by a thousand cuts" (timing, then alternator, then AC Compressor, then motor mounts, then crank pulley, then torque mount, then fan pulley bearing, then rust on chassis leg, then welding on my engine block?!......) or the "frog sitting in water that doesn't realize it's slowly heating up".


Either way, it does feel good to be putting it back together but this is my first timing belt job on the Audi and pulling the cams is still a little cringy for me.


I'm working on the driver's side so if the tensioner you have turns out to be for bank 2 (077 109 087 E), that would be awesome. Let me know what you want for it.


In the meantime, I may put the bottom rail of my bent one on the anvil and see if I can't carefully tap it back square.


Any wisdom on the viscous fan pulley bearing? (077 121 211) Can't seem to find the bearing itself anywhere.


Thanks again!

[danspach]

Afternoon all,

Plenty of updates and will post up with pictures but have run into an issue.

I bought a “used, good” cam chain tensioner (identical part number, thought officially out of a 2005 Touareg) and now that it’s installed and the cam caps torqued, when I remove the tensioner tool, the tensioner does not expand and put tension on the chain.

Tough for me to check my work with no tension on the chain.

I know to a degree the CCT does its job by being fed oil from the running engine but I’m not even interested in rotating the cams by hand with so much slack on the chain.

Do I have a garbage part or am I missing something here. Yes, it’d be easy to blame the part but in the meantime, wondering if there’s another cause. What causes it to collapse/not expand?

Thanks for any help on this one.

[ShelbyM3]

IMG_6437.jpg
You are correct in that oil pressure keeps tension, but there is also a spring and insert inside to help maintain a baseline pressure.

IMG_6435.jpg
It’s possible this side of the CCT is also jammed or dry causing it to not expand and keep chain tension.


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[danspach]

Damn. So barring this thing just relaxing and deciding to expand, seems like it all needs to come back out again.

😒

Thanks very much for the confirmation, Shelby. Guess I’ll look to take it apart and clean it out. I have the old bent one as comparison so will see how they may differ.

I was able to reinstall the “wings” by hand tightening the bolt and then limped the cam around and my alignment marks look better than when they came out. Plus I’ve installed all new hardware so I’m almost good at getting the cams in and out now.

[ShelbyM3]

My theory is the tool that compresses the tensioner does so from only one side and if enough pressure is applied the cylinder can get tweaked in the bore and then not want to come back up.
I am by no means an expert, I’ve just refreshed my tensioners and pulled them all apart. Part of me wonders if you couldn’t take a big flat head or a small pry bar and, while being very cautious, trying to see if you can get the tensioner to pop out? But, here’s the caveat, the cylinder that expands to keep tension is on the top of one and the bottom of the other tensioner, in my experience. On my 2.7, the driver’s bank 2 extends from the bottom which I imagine makes it more difficult to get to once installed.
Slap the old bent one in a vise and pull it apart. I imagine it’ll be a little tough, but then you can get an idea of what is going on. Maybe the used one lost the spring or it broke? You’ve got one of those in the bent one! It really sucks you’ve thrown new hardware in only to have to potentially pull it right away!

Another thought I just had and it’s not meant to be disrespectful is, is the cam timing set correctly relative to each cam? On the 2.7 this is ALWAYS a heavily discussed topic because it’s not symmetrical or precise in its process. My brains wants to think if your chain had “slop” in the top, the bottom could be tight and expanding but maybe not reflect that from what we see in the picture? Probably not, but I’d poke around and do double checking before I ripped it all apart again. I’d personally feel foolish if the tensioner was just fine after all you’ve been through. You should see more chain tension.


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[danspach]

Another thought I just had and it’s not meant to be disrespectful is, is the cam timing set correctly relative to each cam? On the 2.7 this is ALWAYS a heavily discussed topic because it’s not symmetrical or precise in its process. My brains wants to think if your chain had “slop” in the top, the bottom could be tight and expanding but maybe not reflect that from what we see in the picture? Probably not, but I’d poke around and do double checking before I ripped it all apart again. I’d personally feel foolish if the tensioner was just fine after all you’ve been through. You should see more chain tension.


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Hi ShelbyM3,

I think you’re 100% correct.

Thanks for the response. Really appreciate the input. It’s a driver’s side so the cylinder extends on the bottom and I actually had the same thought about the cam timing…(not sure how it’s going to tighten the chain on top when the tension’s applied on the bottom. The critical distance is over the top. I’ll definitely be taking another look before I take anything apart. Something’s up here. (Honestly, if I had to take it apart, I’d be more annoyed about having to clean off the RTV I so carefully applied than anything else. My engine hasn’t been this clean in a WHILE.)

I’ve read similar experiences about the subjectivity of timing marks and chain rollers with the 4.2 also but thought I was careful to mark them before I took them out so not sure what happened.

When I first took the valve cover off and set it to TDC, the intake cam was pretty well off the mark and the exhaust wasn’t much better so when I replaced the tensioner I offset the previously matching paint marks by one tooth to retard just the intake cam but the number of rollers wouldn’t have changed.

I definitely did something wrong here, though. Like you said there shouldn’t be any slack in the chain. I’m goin’ back in tonight.

Some pics of the cam timing.

As I found it originally:

Intake:

Exhaust:


AFTER Re-install with new tensioner:

Intake:

Exhaust:

[danspach]

In looking at my recent pictures above - ("after reinstall") I think my plan is to leave everything bolted down and use my exhaust cam as the "reference point" as it's most closely aligned (cam timing mark to the arrow on the cap) and advance the chain one link up to the intake cam.

I'm hoping once it gets far enough around the intake cam, it will be slack underneath and then can release the tool and have it take up the slack on the underside.

I'm also doing this with the driver side (bank 2) under valve spring tension so when the cam is "relaxed", I don't see the marks....I need to put the cam bar on and use it as a wrench to see how I did.

Also, is it possible to get the cam notches and cap arrows lined up perfectly? Knowing my car "ran" as it was originally timed, I'm already ahead of the game (and hoping to gain a little power) but is it possible for them to be perfectly aligned?

[2.ohhh]

Hopefully I'm not too late here to save you from some extra work. I've been out of the Audi game now for a year and don't check back here that often, and it's been about 2.5 years since I did this part of my project...but referring to my old pics, I may have some insight.

Now I know that I was working on the BCY, but it should be the same for yours. Looking back at my pics, my tensioner was slack too when I reinstalled. Once I put on the timing belt and gave it some rotations, it pops back out with even minimal oil pressure from hand turning over (I still had oil in mine at this point). After you roll some revolutions, take a look at your marks then and see where you stand. Mine lined up exactly once I did this and then tweeked the cam gears a few times to get the phase correct between the 2 banks.

Some reference pics, notice my new chain and original tensioner with new shoes is slack with no tool on it just after reinstallation:





And re-aligned once all was rotated as a complete assembly. In all fairness, I had to re-set the tooth count on the driver's side once myself, it's a real pain to get in there properly under valve spring tension.





I hope this helps a bit. Even if you are off a tooth here, you won't damage anything with a hand roll over. I forget the direction of rotation, but be sure to check and only go the proper way.

[danspach]

Hi 2.ohhh,

Thanks for the input. I really appreciate it, especially with the pics from the archives. (Nice to see these engine look so clean!) Our situations do look similar but I think my chain roller count is off. I tried to be careful in how I marked it before I took it off so have not become the expert in 16 v. 15 or 15.5 links threads but in my picture the chain looks to have much more slack than yours. Even when I rolled the cams back with the cam lock tool like a wrench to see how my alignment looked (to take the "after reinstall" pics), I felt like I needed to keep my hand on top of the cam sprocket so the chain wouldn't skip a link. That doesn't seem right.

I haven't been back in the garage in a few days (trying to give it some thought before I do something stupid instead of just doing something stupid) but think I'm going to put the tool back on the tensioner and adjust the chain so it's one link tighter across the top distance and see if that allows the tensioner spring to do its thing.

[Calif_Kid]

I know that you're working on a V8, but thread https://www.audizine.com/forum/showt...-cam-bar-issue might be good to look at even though it is for a 2.7T. In post #18 of that thread, I showed a picture of how I tie wrapped the timing chain to the cams and tensioner after carefully coounting the links with everything off the car, and then dropped everything in, and the timing chain was tight enough with the tie wraps where it couldn't skip a link. My tensioners weren't giving me any issues, but I was just changing the tensioner shoes. Main thing is that you might be able to set the number of links with everything off the engine, add tie wraps, and then drop everything in.

- Jim

[danspach]

Hi all,


TLDR: Is it possible I have a weak/bad hydraulic timing belt tensioner even though it’s brand new? Why else would it not be able to keep the requested 5mm gap?


-------

Since my last update, I’ve refinished a bunch of parts, acquired seemingly NLA parts from Audi Tradition (shipped to France of course since they won’t ship here…thanks Audi – really appreciate that), replaced the passenger side cam tensioner shoes and have started to put it back together.




Installed the belt rollers and tensioners, threaded the belt, pre-tensioned it (semi-ambiguous instructions from Blauparts), aligned the cams with the bar, tightened the sprocket bolts, removed the crank pin and hand cranked the engine.


After several rotations, my passenger side cams were perfectly aligned but the drivers were off so looks like I need to take them out and try it again. (It did build oil pressure in the driver’s side tensioner though for anyone who saw my earlier concern.) In the process of hand-cranking the engine, I noticed something and wanted to ask the group’s opinion.


I used a 5mm allen key on the hydraulic tensioner (see pic) to set the gap before pulling the pin but after pulling it (and using the allen hole in the hydraulic tensioner to help give it room to extend) it doesn’t keep the 5mm gap after 2, 4, 6, 8 rotations of the engine and as a result, the tension on the belt between the passenger cam sprocket and the tensioner seems pretty sloppy. I’d guess the gap is more like 2.5 – 3mm but could actually measure it.


It’s a brand-new NTN tensioner that comes with the Blauparts kit. Is it possible that I got a bad/weak part? It has zero miles on it. Is there any other reason why I’d be seeing slack in that run of the belt? The rest of it looks/feels good – tension wise.


I need to take it all off to reset the driver cams so while I have it off so wondering if I should investigate a new hydraulic tensioner. Is there any way to test them to see if they have the gusto?


Blauparts says to “pre-tension” the belt with the eccentric pulley by aligning the handle of the two pin wrench with the centerline of the water pump pulley. Naturally, it isn’t a full wrench they sell these days but a “bit” that acts like a two-toed crow’s foot so I aligned the bit perpendicular to the ratchet handle and lined it up that way with the water pump pulley. Anyone object to this approach?










This is what was left of the screen on my passenger-side chain tensioner. Left with the choice to buy a factory part , take a chance on an eBay tensioner or put the one I know was working back in but without the screen, I went with the last option.

[danspach]

Went out to the garage and started thinking about this...my driver's side cams are off.


I'm missing something. I have to be. The picture below is of my driver's side exhaust cam....the one with the flat spot for the diamond-shaped washer. My cams are currently locked to each other with the cam bar and this is where my exhaust cam lines up. I understand I can change the relationship of the intake cam to the exhaust cam by rotating the intake cam a tooth this way or that but when the cams are timed to each other with the bar, this is where the exhaust cam will be and there ain't no adjustment, right?

I know I'm missing something.

This is where it sits now. Clearly not lined up between the cam cap arrow and the notch on the cam.





This is where it was when I took the car apart. Also, clearly not lined up between the cam cap and the notch on the cam...in the identical spot. A good thing, I suppose, because I haven't done anything to screw it up...but a bad thing because it doesn't seem like even if I wanted to change it (align it perfectly), I could.

Can someone help me understand this?

[ShelbyM3]

How does the intake cam look? Didn’t you also mess with the timing on this bank as far as adjusting the intake cam or something? How many links are between marks?


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[danspach]

How does the intake cam look? Didn’t you also mess with the timing on this bank as far as adjusting the intake cam or something? How many links are between marks?


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Hi Shelby,

Thanks for your note. I did change the relationship between the intake and exhaust cam and rotated the intake cam one tooth on the sprocket. It's still outside the notch - but closer than it was originally...on the other side.

Driver’s intake when I took it apart:






This is what the driver’s intake now.






I haven’t counted the links but rather used my paint marks from when I took it out to make sure I kept the right distance. Now that everything is locked down I’ll count them and try and get a representative picture. (I’ve almost gone blind reading threads over the years for how many links on the driver’s side vs passenger, etc.)

I just don’t like that the exhaust cam notch doesn’t line up on the cam ca and that I can’t see any way to adjust that.

[ShelbyM3]

On your pre-disassembled exhaust pic you’re slightly advance both intake and exhaust. On the post pics you look to be retarded on the intake and advanced on the exhaust, if I’m looking at that correctly. Something seems fishy.
Also, pop the cam gear loose and manually adjust the exhaust cam with channel locks or something, then torque it down. Cycled the system and check. Pop cam, adjust, torque, cycle.


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[danspach]

On your pre-disassembled exhaust pic you’re slightly advance both intake and exhaust. On the post pics you look to be retarded on the intake and advanced on the exhaust, if I’m looking at that correctly. Something seems fishy.
Also, pop the cam gear loose and manually adjust the exhaust cam with channel locks or something, then torque it down. Cycled the system and check. Pop cam, adjust, torque, cycle.


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Yup. I rotated the intake cam relative to the exhaust cam one tooth because it was so far from the notch when I took it apart. The exhaust cam is in exactly the same spot before and after. Only the intake has changed.

When you say "pop the cam gear", are you referring to the sprocket with the chain connecting the intake and exhaust cams or the timing gear on the exhaust cam on the outside of the head with the belt?

If you mean the one with the chain, that would answer my question. I don't know how to do that and haven't really seen it referenced.

If you mean the one with the belt, I've done that and locked the exhaust cams with the bar (pic below), tensioned the belt, torqued, rotated and it ends up where it starts. That's where I'm confused. Don't understand how you can align the exhaust cam perfectly with the notch. Once the flat spots on the two exhaust cams are facing each other - locked with the bar - how can you change that?

[ShelbyM3]

Gotcha. The one with the belt.

So I think you’re off on your timing chain. It sounds like you have the process down just fine. I think you’re off a link. Just my guess.


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[danspach]

Gotcha. The one with the belt.

So I think you’re off on your timing chain. It sounds like you have the process down just fine. I think you’re off a link. Just my guess.


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ok, thank you, sir for confirming. Always appreciate the sanity check.


My exhaust seems to be "it is what it is" because I can't change it's alignment once the flat spot on the cam nose is in it's place. (It's almost like the wrong cam is in there) ...and the intake side is one tooth "different" from where it was as the notch has migrated from one side of the cam cap triangle to the other but the number of links hasn't changed.

I'll take a good picture and post it up.


Is the lift in your profile pic a Twin Busch? Do you like it?


For anyone else playing along and doing this job (or considering it), I have literally 900+ photos of just about every step and part involved. If anyone has requests, let me know.

[danspach]

Here’s the starting point on the exhaust cam marked with yellow paint pen on the roller barrel and the pin:







The ending point on the intake cam but it’s actually ½ roller too far because it’s halfway between at the cam cap mark:







This is the whole span. It looks off because you have to take from an overhead angle to see them all. Call it 16 rollers or 15.5 if you stop at the cam cap mark.

[Calif_Kid]

I know that you're using the camlock bar, but are you also using the crank lock pin? Hopefully you are using the crank lock pin, and the exhaust cams marks should line up OK. Up in post #53, I mentioned a thread about timing belt setup for a 2.7T V6 including the chains between the intake and exhuast cams, but I'm not sure if the info/setup is the same between the 2.7T V6 and the 4.2 V8, but if you haven't looked thru that thread, I suggest taking a few minutes and going thru it.

- Jim

[danspach]

Hi Jim,

I am indeed using the crank lock along with the cam bar. In the picture above showing the engine with the cam bar, the crank pin is in as well and everything is locked down. That’s why I don’t understand how the exhaust cam is off.

I had read the thread you’d posted above (thank you!) but was past the point of zip tying it to keep it in place. It’s a good idea though and while hopefully I won’t need to do this again , if I do I can give it a shot.

Passenger side went very smoothly. Guess I’d had some practice by then.

[ShelbyM3]

It is possible that you have chain stretch and the lack of oil pressure in the tensioner causing it to be off. 900 pictures kind of guy myself…haha. The big picture pictures do your work a lot more justice and don’t make it look so far off.

As for the Twin Busch, yes and I love it. I got the low-rise scissor about 5 years ago now. It’s perfect for my space, but she had a bit learning curve, like I think most lifts do. I think it’s perfect for the serious hobbyist, but if you’re a professional, a 2 post is better.

[danspach]

It is possible that you have chain stretch and the lack of oil pressure in the tensioner causing it to be off. 900 pictures kind of guy myself…haha. The big picture pictures do your work a lot more justice and don’t make it look so far off.

As for the Twin Busch, yes and I love it. I got the low-rise scissor about 5 years ago now. It’s perfect for my space, but she had a bit learning curve, like I think most lifts do. I think it’s perfect for the serious hobbyist, but if you’re a professional, a 2 post is better.

It's a tiny picture of the lift but she looks like a beaut! Clearly from this thread, I'm not a professional so instead of asking you 400 questions, could I trouble you for the model number?


Thanks for the input on the cam timing. I guess where I am now is: it ran when I took it apart and it "should" run better now where the cams are so I'm gonna spin it by hand one more time before I put the covers on and finish putting it all back together. I touched a lot of systems doing this so taking my time but I have an '86 535i sitting in my driveway looking even more sad (amazingly) than when I bought it. It's time for the Audi to make some room.

[ShelbyM3]

https://www.twinbusch.com/product_in...?products_id=8

TW S3-10 E - I will say when I got mine it was $2,000 to my door. Looks like they’ve gone up in price.

I think you’ll be good, as far as bending valves and destruction, if it rotates freely.


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[danspach]

"....as far as bending valves and destruction"


That was amazing.


Once I get my serp belt tensioner, I can get back at it. For now, I'll be ceramic coating the airbox and engine covers.


Thanks for the link to the lift.

[Calif_Kid]

I've read (at least on the 2.7T) that the intake cams and the cam chain tensioners are bank specific (driver vs passenger side), but not sure about the exhaust cams. With the cam lock bar in place, I would expect the notches on the exhaust cams to pretty well match with the marks on the cam caps, and the intake cam notch positions would depend on the number of links in the cam chain, the condition of the cam chain tension shoes plus how extended the cam chain tensioner is, plus on the condition (possible stretching) of the cam chain.

If you're pretty confident that everything is correct or fairly close, and can hand crank the engine without any issues, then if you have Vag com, you could attach the valve covers with a few bolts, start up the engine for a short time, and check measuring blocks 91-93, and the values in 93 should be say +-6, and if you are off by a link on a cam chain, then you might see 25 or -25. I listed quite a few threads below with some of them mentioning that if the value in MB 93 is somewhat off (say +6 or -6), that they loosen the cam bolt, and use vice grips to rotate the exh cam very slightly, and then retighten the bolt. I know that the cam positioning sensors are on the end of the intake cams, but all of this is really assuming that the exhaust cams are timed correctly to the crank, so I would hope that the notches on your exhaust cams match the cam caps pretty well expecially since you're using the cam lock bar. Most of the info I've seen is for the 2.7T, so not sure about possible issues with the 4.2.

Did you check or install new shoes on the cam chain tensioners? Good luck!!
- Jim

https://www.audizine.com/forum/showt...ition-question
https://www.audizine.com/forum/showt...ht=timing+belt
https://www.audizine.com/forum/showt...ht=timing+belt
https://www.audizine.com/forum/showt...ht=timing+belt
https://www.audizine.com/forum/showt...ht=timing+belt

[danspach]

Hey Jim,

Thanks for the threads. Similar to the 2.7, the cam chain tensioners are indeed bank specific. On the 4.2 at least, the driver's side has a piston that pushes down to extend the lower shoe against the chain and the passenger a piston that pushes up on the upper shoe. Two different part numbers. I've changed the tensioner shoes on both sides.

Yup, hand cranking is nice and smooth. (with no plugs I can practically do it using two fingers on the ratchet).

With the crank locked with the pin and the cams locked with the bar, I'd also expect the alignment of at least the exhaust cams to be perfect to their notches.

In fact, unless I'm missing something, nothing - chain stretch, tensioner pad wear, tensioner oil pressure or even my intense desire to finish this project....nothing should have an effect on the alignment of the exhaust cams to each other. Timing of the rest of engine aside (intake cams and crank)...that exhaust cam, locked to the other exhaust cam with the bar should see the cam cap triangle line up perfectly on the notch of the cam. I don't really want to consider it but it makes me wonder how the cam sprocket (the one the chain goes over) is attached to the camshaft itself. It's like the lobes of that cam are incorrectly indexed relative to that flat spot on the nose of the cam.

I think I'm going to button it up and as you suggest fire up VCDS and check the measuring blocks. This is where the exhaust cam was when I took the car apart and it ran. I was hoping to improve the timing and think i have by rotating the intake cam by one tooth but there's only one real way to find out.

[danspach]

Evening all,

Plenty to update on but the short version is the car is back together and I fired it for the first time this past weekend. Progress has been “slow” but I’m really pleased with the experience gained, the care taken and – for the most part – the end result.

Nothing is leaking, no CEL’s, and no expensive co-spatial event between piston and valve. Almost everything is working the way it should.

That is except for what sounds like the chain tensioner on the driver’s side.

After the fuel system was pressurized and it ran, it became VERY apparent there was a “noise” coming from the driver’s side near the end of the tensioner. This is the one I’d swapped out after the original was bent.

It sounds to me like the chain rubbing up against the inside of the valve cover so after taking several videos (and trying to keep my cool) I took the valve cover off (again, though I’m damn quick with that now) and the chain has no slack in it whatsoever. The valve cover does seem to have some chain wear marks but they’re consistent with marks in pics when I took the cover off initially (two years ago).

I did a thorough a visual inspection and didn’t see anything out of place. (Part of me was hoping for something basic and embarrassing.)

As an initial step, I did swap the solenoid with the one that was on the original tensioner, and nothing changed. I haven’t tested the solenoid for the stated resistance (10-18 Ohms) but seems like if the solenoid was bad it would fail in an unpressurized state. If that logic is flawed, please correct me.

My next step was going to be to put the valve cover back on, fire it up and unplug the solenoid to see if anything changes but not sure that will really accomplish anything at this point.


Here’s the video. Any/all experienced ears appreciated along with thoughts on next steps. Thanks in advance!

https://youtu.be/D_AoA2FEEgY

[ShelbyM3]

Couple questions for you:
-Why did you start all of this? Was it that noise or just maintenance?
-Do you have VCDS? You should check measuring blocks for timing to see what they say. That driver’s side bank 2 seemed challenging to time.
-Did you ever take the lifters out when you took the cams out?

What if it’s a cam lobe slapping a lifter?


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[danspach]

Couple questions for you:
-Why did you start all of this? Was it that noise or just maintenance?
-Do you have VCDS? You should check measuring blocks for timing to see what they say. That driver’s side bank 2 seemed challenging to time.
-Did you ever take the lifters out when you took the cams out?

What if it’s a cam lobe slapping a lifter?


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Evening sir,

The original job was valve cover gaskets that went sideways and turned into a timing belt job that spiraled into a front end restoration.

I do have VCDS and will use the software to check some things. I still need to do some reading to see exactly what those things are and where to find them. (I really wanted to make sure there wasn’t anything obviously wrong under the valve cover and it all looks ok so that’s where I’m at).

I initially thought it might be a lifter but it’s so close to the tensioner I immediately started casting blame at the used part. I did not take the lifters out when I took the cams out. As miserable as it sounds I feel better running the engine after seeing inside the valve cover so will run it for a longer time tomorrow. Maybe if it is a lifter it’ll relax? Had that happen to my 944 after it sat for a while.

Listening to the video, do you think it could be a lifter?

[danspach]

So I bought some “LiquiMoly Hydraulic Lifter Additive” and my thought was to button it up again, put the additive in and - while it’s circulating in the engine - run the VCDS Measuring Blocks for cam timing. I’d think if there was a serious problem with a lifter, it would have thrown a CEL and after several (5-6) starts, I didn’t have any. Next in the rotation was to add their engine flush and then change the oil. I did my best to keep sensitive parts way from the elements but I don’t want that oil in there for much longer.


@ShelbyM3 – I do see now that it would have been wise for me to go another step and take out the roller rockers and lifters to keep them bathed in oil. My engine has been out of commission for quite some time and that wasn’t the plan but should have been more cognizant of that part of the valve train.

Live ‘n learn, I guess.

Even with this hiccup, it was really cool to hear it run and see all of the new belts, pulleys and pumps doing their thing again.

I’ll report back and, in the meantime, if anyone has thoughts or comments, I’m all ears!

[ShelbyM3]

Evening sir,

The original job was valve cover gaskets that went sideways and turned into a timing belt job that spiraled into a front end restoration.

I do have VCDS and will use the software to check some things. I still need to do some reading to see exactly what those things are and where to find them. (I really wanted to make sure there wasn’t anything obviously wrong under the valve cover and it all looks ok so that’s where I’m at).

I initially thought it might be a lifter but it’s so close to the tensioner I immediately started casting blame at the used part. I did not take the lifters out when I took the cams out. As miserable as it sounds I feel better running the engine after seeing inside the valve cover so will run it for a longer time tomorrow. Maybe if it is a lifter it’ll relax? Had that happen to my 944 after it sat for a while.

Listening to the video, do you think it could be a lifter?

Boy howdy do I know that black hole of “maintenance” gone south quicker than my first time. You’ve come a long ways!
I believe it’s measuring blocks 90,91,92,93 to check for timing correlation and/or correction.
I see no problem with your plans. If it were seriously out of sync you’d know it by now. I bet there are plenty of C5’s on the road with a bank 2 cam issue nobody even cares about. Haha. It should be pretty apparent when you look at the timing correction for bank 2 if you are off a tooth or not. I’d check that before you put in the lifter additive. Should only take a few minutes to get your answer if you need to redo the timing.

It’s possible a lifter collapsed on you and it’s just getting smacked every time the cam rolls around, but I’m only speculating. Spit-balling ideas. What are the chances a cylinder 5 lifter gets stuck when you are replacing a CCT on bank 2!? Did you replace the shoes on both CCTs? Maybe the bank 2 CCT is gonna have a little more friction until it beds in the new shoes on the chain?

Ultimately, she runs, you totally redeemed yourself, and you’re on the homestretch! Check your timing and get your answer.


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[danspach]

Thanks for the note, the feedback and the shot in the arm. Feel like I’m close! (the tie rod pinch bolt is a totally separate fight! 😊 )

I did indeed do shoes on both CCT’s. Think once I get it back together and started, I’ll unplug the CCT on bank 2 to see if the noise changes.

Then I’ll hop into vcds (thanks for the measuring block addresses) and look at the numbers. Really curious to see how they look.

I’ll keep you posted on the cam correlation results.

[danspach]

Ok, so have tried a few things to get more data about what’s happening.

With the valve cover off:
1. Checked the cam chain itself and there is no slack whatsoever in the chain.
2. Tested the resistance on the solenoid and it’s within spec (spec is 10-18 Ohms and tested at 13.7)
3. Took the solenoid off to ensure the tensioner piston (that the solenoid pushes on) had free movement – which it did. The green o-ring was also in good shape.

Put the valve cover back on and:

1. I ran the “Output Tests” – which on this vintage, I guess you can only do sequentially. I was able to hear all of the valves and pumps do their thing and specifically, the solenoid for both tensioners
2. Looked at measuring blocks 91, 92 and 93 – my numbers in block 093 don’t look good (see below) but let the car warm up because in order to test the tensioner activation, the car needs to be up to temp (>80* C)
3. Even when the engine was up to temp, >2000rpm showed no activation (blocks 091 and 092).

I’m thinking because the numbers are too far out, the car has disabled the timing adjustment because when I turn the car off, I can see the “Cam Adjustment Intake Status” in both groups 91 and 92 flash to “ON” momentarily along with a clicking of the solenoid so there is communication with the tensioners.


Here’s the screenshot of the Measuring Blocks:




….and a link the video. The values change at about the 1:10 mark which I’m still trying to understand. The sound is haunting me in my sleep.

https://youtu.be/njMxjyYDBX0

[danspach]

Ok, so gave this some thought, did some research, watched a bunch of YouTube vids and think I have a better understanding of what may be happening. My primary concern is the terrible noise coming from that part of the engine and I was confused when I didn’t see anything obvious (scoring/marks) under the valve cover and when the cam chain had no slack in it.

It occurred to me that on the bank 2 tensioner, the piston and shoe extends downward so I wouldn’t necessarily see anything because the nonsense was happening on the underside.

Tomorrow I’ll take the valve cover off and stick my endoscope in there for a better look. Think after running the car for the different tests, I’ll see evidence of something that’s making all that noise. I also used this video for a comparison of the noise. It's a lower rpm but it sounds the same to me:


My S6 yesterday:
https://youtu.be/njMxjyYDBX0

"GEORGE G's" A8 from 8 years ago:
https://www.youtube.com/watch?v=DFA4eDNiU_A


I also used the stethoscope to try and pinpoint the noise and it’s focused on the tensioner and not really a cylinder (trying to rule out a lifter).

Anyone have a recent data point for a reliable cam chain tensioner that doesn’t represent 25% of the car’s value?

[ShelbyM3]

These guys have one with a warranty…I think Wolf is solid.
https://wolfautoparts.com/camshaft-c...e-ps16952.html

I’m not an expert, but it appears your timing is really close on bank 1, but that CCT is maybe stuck for bank 2. I wonder if we’re hearing the CCT actuator smacking the piston inside the CCT? Sorry Dave. Big picture I think this could have been much worse and I’m curious to see what you find.

I read a couple forum posts, as well, and saw a B5 S4 and C5 RS6 thread both discuss the CCT being stuck extended when the Bank 2 phase was really high 15-25 range.

Also, your comparison video is terrifying! The damage to the cylinder head was impressive and I cannot believe that engine didn’t meat its maker.

Also also, double check your timing chain on Bank 2. Just one more time to make sure the link count is correct.


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[danspach]

These guys have one with a warranty…I think Wolf is solid.
https://wolfautoparts.com/camshaft-c...e-ps16952.html

I’m not an expert, but it appears your timing is really close on bank 1, but that CCT is maybe stuck for bank 2. I wonder if we’re hearing the CCT actuator smacking the piston inside the CCT? Sorry Dave. Big picture I think this could have been much worse and I’m curious to see what you find.

I read a couple forum posts, as well, and saw a B5 S4 and C5 RS6 thread both discuss the CCT being stuck extended when the Bank 2 phase was really high 15-25 range.

Also, your comparison video is terrifying! The damage to the cylinder head was impressive and I cannot believe that engine didn’t meat its maker.

Also also, double check your timing chain on Bank 2. Just one more time to make sure the link count is correct.


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Looking at VCDS, there is no activation of either tensioner in it's current state but the passenger side tensioner - and head in general - is dead quiet (relatively speaking). It actually sounds lovely through the stethoscope.

This is more of a guess but when I rotated the engine by hand to check timing, I could see the tensioner (bank 2) popping up and down as the valvetrain did it's thing. Thinking without activation from the ECU/Solenoid and if the tensioner is bad, it's only got the baseline spring tension but not much else to keep it from bouncing around. It doesn't have the "machine gun" sound to it because I have fresh tensioner shoes but something's rapping against something it shouldn't in there.

To wit: The Plan

I spoke to an Audi specialist I trust and knows these cars (really) well and he spoke to his parts distributor who has a brand of tensioner he's been selling for 20 years because the factory ones have always been overpriced. I'm just unwilling (at this point) to take another chance on a used tensioner though the fact that Wolf has any warranty is pretty cool - even if it's one month.

The new tensioner will arrive in the coming week or two and until then I'll prep the car for Timing: Part Deux.

The goal now is to determine how little disassembly can I get away with to get the new tensioner in there. I've sealed the AC system after hitting it with some dry nitrogen and a new receiver/dryer so that has to stay in place. Looks like service position and leaning over for the whole thing. Luckily, I have a million pics to refer to and all of the parts and hardware are new.

At least I have a (MUCH) better understanding of the car and it's timing...plus I learned some new German. In the 90's measuring blocks in VCDS , "KW" = Kurbelwinkel or "crank angle"


To your point about the terrifying video - it's pretty impressive how many engines have made it to that point - broken shoes, NO shoes, grinding through the tensioner! - that didn't actually go "boom".


Thanks for sticking around for this whole saga!


I do plan to post a lot more of what I did in between "the problems". I touched a lot of stuff doing this job and have pics of all of it.