Warm start rattle solved on my car!

[Jake@JHM]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

[bioluminescent]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

I agree with this completely, and won't do this fix until I get the timing service done because I want to be aware if the components are deteriorating more.
But it's entirely logical that these valves is a potential source of timing failure, if not the source. So, if someone does a timing service without replacing these valves, it seems like there's a good chance the real problem was never fixed. It makes a lot sense to do this job while doing the timing service, or before you get any rattle.

[combsatl]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

I'm by no means an expert on B6/B7 S4's, but my 2004 S4 has 132k and it's rattled for the past 50k. I find it very difficult to believe that a broken guide would last for 50k and still show only beginning signs of issues (only a cold start rattle). It's not that I don't believe you - you guys have vastly more experience with this - but, more-so, for so long it's been commonly accepted as "this is a $7k required maintenance if you want your car to last". I find it a little odd that, now, 4 out of 5 people have tried this and it's corrected their issue at hand but isn't even being given a second glance by the experts.

Sorry man, but that really seems fishy to me.

EDIT: Not to mention - if you're replacing all the timing components, and one of those check valves has failed, the customer will be right back in the same place in a bit. The timing system will depressurize, the chains will slap against the guides which will lead to them cracking. Why wouldn't you include that as part of the servicing if they're being shown to fail?

[Denker]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

Fixed the issue yes, but perhaps not the cause? I would think that this would now be a recommendation during this service to minimize the chance of reoccurrence down the road. It's such a cheap bit of insurance at the very least along with the labor overlap.

[Kookie]

Fixed the issue yes, but perhaps not the cause? I would think that this would now be a recommendation during this service to minimize the chance of reoccurrence down the road. It's such a cheap bit of insurance at the very least along with the labor overlap.

What he said

[Kookie]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

I would say it's a combination of both Jake.

The adjusters do fail due to wear, and cause slop in the chain tension.. but there are hydraulic components that require the oil that these check valves store. If they are seeping, or leaking and allow the oil from the heads to join the general population of oil in the engine, they're effectively accelerating the rate of wear in the adjusters as well as aiding in cracking the guides.

I'm not discounting what you're saying, but I do think that these are PART of the timing chain issue and should be part of the kit. They're inexpensive(comparatively speaking), and with minimal labor during timing chain kit install....it wouldn't make sense to leave them while in there.

[BCsniper]

I'm not discounting what you're saying, but I do think that these are PART of the timing chain issue and should be part of the kit.

This is how I see it. I am not going to say that any one part of the system is the cause of all the timing problems that happen with the V8 S4's. I do think that all of these things add into why we have problems, so to leave any one item out would seem to be a mistake.

You guys remember this, right?

By the way, I was looking through my Bentley Software for more information about these valves and I saw it mentioned: "Note: If irregular valve noise occurs repeatedly during short journeys and disappears after extended driving, the oil check valves must be replaced."

So it looks like Audi knew all along about this issue but nobody apparently went searching through the factory repair manual information to find this stuff out.

If Audi came out to officially say that this is a problem then I would say that it is something that might want to be addressed.

[IslandHydro]

For those of us with highly intermittent rattle, some sort of occasionally sticking component must be to blame, whether that be an adjuster or a check valve. I don't see how a broken guide could result in this type of intermittent behavior. And, as a followup to this, you have to wonder how many broken guides are CAUSED by the stuck component allowing the chain to slap around during those moments of slackness. Or for that matter, how many adjusters are worn prematurely by check valves not keeping tension on the chain? Given how cheap it is to change out these check valves, seems only sensible that one would try this first. It would be really interesting to find out how many people who have experienced timing chain failures started out with highly intermittent symptoms.

[dolphin B6 S4]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

In that case I have a brand new broken guide or a failing adjuster, right? I really hope not, may as well update this.. I had a couple (2-3) small incidents of cold start and warm start rattle BEFORE I changed my oil, and that was out of maybe 15-20 starts. I still had the oil that our dealership uses in the volkswagens in my car which is castrol(?) 5w30. Now there is fresh lubro moly in it and start ups are still quiet. I think it was probably a combination of those weak check valves + watery oil that was causing my rattle.

[rixonichard]

No wheels are turning. Like I stated previously in this thread that even though is valve may be failed, the clack is because the guides are broken/cracked and/or your mechanical adjuster is failing. Applying pressure to the broken guide is only going to mask the sound of an issue that could lead to engine fatality. Every time we have a customers car in here for timing chain jobs with warm start rattle, replacing the broken guide with the new updated guides and new adjusters have solved the issue.

Have you ever taken apart an engine that rattled and not found broken guides? If not that would lend weight to your theory that every engine that rattles has broken guides. However, it is possible that there are cars out there that rattle with guides intact. The chicken and egg question is whether the rattle causes broken guides, or if the broken guides cause the rattle. Since it is impossible to know if the guides were in good shape when the rattle started, the only way to get an answer to the question is to find someone who had chain rattle without broken guides.