TTRS - Strange sound when cold over 2k RPM?

[Marty]

Just reproduced the problem! But it stopped before I could take a video.

My rattle happens right at 2200-2400 RPM, and is silent below that. I'll snag a video soon enough. It does not sound healthy at all, and is of course way more audible with the windows down.

Whatever tech at the dealer thought that this noise was a wastegate should stop working on your car immediately!

So to folks trying to reproduce this:
1) make sure the car is cold and has been sitting for many hours
2) roll the windows down
3) start the car and let it idle briefly to let oil circulate (just a few seconds)
4) slowly rev the engine up through 2000-2500 RPM back and forth an listen. Hear a loud rattle right around 2200 RPM? Bingo! No noise? Try again tomorrow. :p

My noise goes away after a minute or two.

[fourtunes]

Just reproduced the problem! But it stopped before I could take a video.

My rattle happens right at 2200-2400 RPM, and is silent below that. I'll snag a video soon enough. It does not sound healthy at all, and is of course way more audible with the windows down.

Well, it's good to hear that your car's symptoms really do seem to be consistent with mine's. I hope this issue doesn't bug you to the same extent as it does me, though. Else I'd have to feel bad.

Whatever tech at the dealer thought that this noise was a wastegate should stop working on your car immediately!

I don't think the dealership's technicians are to blame. As far as I know, none of the changes (with the exception of the heat shielding adjustment) were made under the dealership's authority. Since it's a newly introduced engine, dealerships supposedly aren't allowed to attempt repairs on their own.

Also, I imagine investigating intermittent problems like this with new engines of this complexity is a bit like debugging a black box. They followed a process of elimination and picked the wrong culprit twice, but at least they didn't give up (I know what that feels like from experience with the S5).

So to folks trying to reproduce this:
1) make sure the car is cold and has been sitting for many hours
2) roll the windows down
3) start the car and let it idle until the idle drops down to below 1000 RPM
4) slowly rev the engine up through 2000-2500 RPM back and forth an listen. Hear a loud rattle right around 2200 RPM? Bingo! No noise? Try again tomorrow. :p

My noise goes away after a minute or two.

A few comments on this (I'll repeat myself, but just in case):

1) In my experience, it is sufficient to let the car sit for 2-3 hours. However, the actual time will vary on ambient conditions (whereas I've had the rattle after letting the car sit for 2 hours in the parking garage at work, the dealership claims they need to let my car sit outside overnight in order to reproduce the problem). Mileage will vary.

3), 4) You needn't wait for the idle to go low. In fact, while that's normally a good idea, it takes a minute away from the failure window. You can slowly rev the engine immediately after ignition, and will likely first hear the rattle well below 2200 RPM. It moves up in the rev range after that and eventually disappears around 3000 RPM (it did for me, anyhow).

[Marty]

Well, it's good to hear that your car's symptoms really do seem to be consistent with mine's. I hope this issue doesn't bug you to the same extent as it does me, though. Else I'd have to feel bad.



I don't think the dealership's technicians are to blame. As far as I know, none of the changes (with the exception of the heat shielding adjustment) were made under the dealership's authority. Since it's a newly introduced engine, dealerships supposedly aren't allowed to attempt repairs on their own.

I just surprised that any tech would agree that the noise was turbo-related given how it sounds. He should have veto'd that call by Audi (if that's who pushed for it).

A few comments on this (I'll repeat myself, but just in case):

1) In my experience, it is sufficient to let the car sit for 2-3 hours. However, the actual time will vary on ambient conditions (whereas I've had the rattle after letting the car sit for 2 hours in the parking garage at work, the dealership claims they need to let my car sit outside overnight in order to reproduce the problem). Mileage will vary.

3), 4) You needn't wait for the idle to go low. In fact, while that's normally a good idea, it takes a minute away from the failure window. You can slowly rev the engine immediately after ignition, and will likely first hear the rattle well below 2200 RPM. It moves up in the rev range after that and eventually disappears around 3000 RPM (it did for me, anyhow).

Good points. I couldn't reproduce it when my car sat overnight this morning, but I was able to after it sat during work. As for the idle, I only suggested it to let the oil circulate. To your point, you just need to let it idle for a few seconds before you can slowly rev it to 2000-2500 RPM without worry.

[fourtunes]

[...] So it looks like this isn't a U.S. specific problem, and that Audi has responded differently to individual cases. Other posts to the thread suggest not everyone is experiencing the rattle. Unfortunately, the thread didn't have much of a conclusion. I asked for status. [...]

I got a few responses on the forum. Three owners confirmed that they're hearing the same noise. Their feedback also suggests that the circumstances are the same. One of the posters says he wrote to one of Germany's major Auto magazines about this problem - apparently they had just run an article on timing chain issues in Volkswagens.

Beyond that, not much in the way of updates from overseas. With one possible exception:

Bei mir tritt - wie in einem anderen thread beschrieben - genau das gleiche problem auf. aber nur bei kaltem motor und standzeit über 6 std. zuerst ist mir das rasseln beim rückwärts rangieren aufgefallen. es tritt aber auch ausgekuppelt und im leerlauf auf. sobald der motor auf temperatur ist, ists weg...war ebenfalls schon mehrmals beim soundfile an audi geschickt, etc..blabla: audi ist das problem bekannt, momentan noch nicht gelöst und wenn die ursache entdeckt wurde, dann gilt es erstmal festzustellen, obs schädlich fürs triebwerk ist. klingt mir auch sehr nach hinhalte-taktik...bin auch planlos, was ich jetzt machen soll...

The same problem - as described in the other thread - occurs for me, as well. But only when the engine is cold and after having sat idle for more than 6 hours. I first noticed the problem when backing up. But it also occurs out of gear and when idling. As soon as the engine is at operating temperature, it's gone... I also have been at [the dealer] several times. Sent the soundfile to Aud, etc... blah blah: the problem is known to Audi, but as yet unsolved. And when the root cause has been determined, then the next step is to determine if it is harmful to the engine. Sounds like hold-off tactics to me... I'm also clueless, what I'm to do next...

Swell.

[Marty]

I got a few responses on the forum. Three owners confirmed that they're hearing the same noise. Their feedback also suggests that the circumstances are the same. One of the posters says he wrote to one of Germany's major Auto magazines about this problem - apparently they had just run an article on timing chain issues in Volkswagens.

Beyond that, not much in the way of updates from overseas. With one possible exception:

Bei mir tritt - wie in einem anderen thread beschrieben - genau das gleiche problem auf. aber nur bei kaltem motor und standzeit über 6 std. zuerst ist mir das rasseln beim rückwärts rangieren aufgefallen. es tritt aber auch ausgekuppelt und im leerlauf auf. sobald der motor auf temperatur ist, ists weg...war ebenfalls schon mehrmals beim soundfile an audi geschickt, etc..blabla: audi ist das problem bekannt, momentan noch nicht gelöst und wenn die ursache entdeckt wurde, dann gilt es erstmal festzustellen, obs schädlich fürs triebwerk ist. klingt mir auch sehr nach hinhalte-taktik...bin auch planlos, was ich jetzt machen soll...

The same problem - as described in the other thread - occurs for me, as well. But only when the engine is cold and after having sat idle for more than 6 hours. I first noticed the problem when backing up. But it also occurs out of gear and when idling. As soon as the engine is at operating temperature, it's gone... I also have been at [the dealer] several times. Sent the soundfile to Aud, etc... blah blah: the problem is known to Audi, but as yet unsolved. And when the root cause has been determined, then the next step is to determine if it is harmful to the engine. Sounds like hold-off tactics to me... I'm also clueless, what I'm to do next...

Swell.

Honestly, your local dealer isn't going to innovate and figure out the engineering solution to this problem. The most important part (reporting the issue, the dealer reproducing it, and Audi Corporate being contacted) has been completed.

The best way to get more traction from Audi on the issue is for every person that can reproduce this problem to take their car in to the dealer and get it reported. I'm going to do the same (I hope neonova6 does, too). I'm sure engineering resources at Audi to work on issues like this get prioritized based on the volume of complaints.

If I were you, I'd go get your car back and start enjoying it! Audi is going to need to redesign the hydraulic tensioner system and/or guide system for the timing chain to really resolve this, so sit back and wait a year while that happens.

[fourtunes]

Honestly, your local dealer isn't going to innovate and figure out the engineering solution to this problem. The most important part (reporting the issue, the dealer reproducing it, and Audi Corporate being contacted) has been completed.

The best way to get more traction from Audi on the issue is for every person that can reproduce this problem to take their car in to the dealer and get it reported. I'm going to do the same (I hope neonova6 does, too). I'm sure engineering resources at Audi to work on issues like this get prioritized based on the volume of complaints.

If I were you, I'd go get your car back and start enjoying it! Audi is going to need to redesign the hydraulic tensioner system and/or guide system for the timing chain to really resolve this, so sit back and wait a year while that happens.

I've been considering that route. But I decided to wait for the results for the timing chain replacements (i.e. another two weeks). Worst-case, the problem will continue to reproduce, but at least I'll have a new chain/etc. (I imagine the problem causes excessive wear, and after weeks of debugging, there's bound to be some fallout).

[joshsmith]

Just reproduced the problem! But it stopped before I could take a video.

My rattle happens right at 2200-2400 RPM, and is silent below that. I'll snag a video soon enough. It does not sound healthy at all, and is of course way more audible with the windows down.

Whatever tech at the dealer thought that this noise was a wastegate should stop working on your car immediately!

So to folks trying to reproduce this:
1) make sure the car is cold and has been sitting for many hours
2) roll the windows down
3) start the car and let it idle briefly to let oil circulate (just a few seconds)
4) slowly rev the engine up through 2000-2500 RPM back and forth an listen. Hear a loud rattle right around 2200 RPM? Bingo! No noise? Try again tomorrow. :p

My noise goes away after a minute or two.

Pretty sure that's the nosie mine makes..

[Marty]

I've been considering that route. But I decided to wait for the results for the timing chain replacements (i.e. another two weeks). Worst-case, the problem will continue to reproduce, but at least I'll have a new chain/etc. (I imagine the problem causes excessive wear, and after weeks of debugging, there's bound to be some fallout).

I view major internal repairs like open-heart surgery: you really don't want to do it unless it's absolutely necessary, due to the risk of complications.

Think about it this way: there isn't a single tech at your dealer that has ever taken apart the 2.5L TFSI engine. Do you want them learning for the first time on yours, for a repair that probably won't fix the problem? Re-sealing everything, setting the timing correctly, etc., isn't a totally trivial task.

Now, if Audi comes back and says they have a revised piece of hardware that they believe fixes it, then that's another story...

But it sounds like you're going to go with it. So neonova6 and I do appreciate that for when we take ours in for the same repair.

[Marty]

Pretty sure that's the nosie mine makes..

Video, video! Let's build a library.

[fourtunes]

I view major internal repairs like open-heart surgery: you really don't want to do it unless it's absolutely necessary, due to the risk of complications.

Think about it this way: there isn't a single tech at your dealer that has ever taken apart the 2.5L TFSI engine. Do you want them learning for the first time on yours, for a repair that probably won't fix the problem? Re-sealing everything, setting the timing correctly, etc., isn't a totally trivial task.

Now, if Audi comes back and says they have a revised piece of hardware that they believe fixes it, then that's another story...

But it sounds like you're going to go with it. So neonova6 and I do appreciate that for when we take ours in for the same repair.

I generally look at it the same way, but given that my engine has already undergone work on the intake and had its turbo replaced, the timing chain replacement/adjustments feel more like an appendix removal following open heart surgery. If the engine developed chronic problems as a result of any of these modifications, I feel there'd be ways to address that situation.

Besides, I still don't actually know for certain that the problem doesn't have potentially serious implications. I do want to know exactly what the problem is, at the very least to know how to avoid it reliably.

[fourtunes]

The thread on tts-freunde.de seems to be getting off track slightly with posters arguing about different types of oil.

But one poster claims that he used to have this problem, and that it went away when he started avoiding short drives (under 6 miles). Supposedly, an Audi expert asserted that short drives (which, according to Audi, is fewer than 30 miles) are problematic for this type of engine and should be avoided. Obviously, this is impractical, but the poster says that he hasn't had problems since extending the length of his commute to ~10 miles. A few other posters back this theory up, but offer no hard data.

So now I'm curious: do those of you who do have the problem often drive only a few miles, and do those of you who do not have the problem hardly ever drive short routes?

[Marty]

The thread on tts-freunde.de seems to be getting off track slightly with posters arguing about different types of oil.

But one poster claims that he used to have this problem, and that it went away when he started avoiding short drives (under 6 miles). Supposedly, an Audi expert asserted that short drives (which, according to Audi, is fewer than 30 miles) are problematic for this type of engine and should be avoided. Obviously, this is impractical, but the poster says that he hasn't had problems since extending the length of his commute to ~10 miles. A few other posters back this theory up, but offer no hard data.

So now I'm curious: do those of you who do have the problem often drive only a few miles, and do those of you who do not have the problem hardly ever drive short routes?

I drive about 7 miles between work and home. I wonder what he would mean by "this type of engine"? Is it really that much different from the other turbocharged Audi engines in terms of the chain tensioning system?

[fourtunes]

I drive about 7 miles between work and home. I wonder what he would mean by "this type of engine"? Is it really that much different from the other turbocharged Audi engines in terms of the chain tensioning system?

They're referring to "Vollgasmotoren" (full-throttle engines), i.e. engines designed to be driven very hard regularly.

I'm no stranger to the argument: the S5's 4.2l FSI is prone to carbon build-up, which causes progressive power loss (noticeable after ~15k miles) and, eventually, misfires (most commonly after ~30k miles); and this problem is aggravated if you have a short commute.

If you read through the discussions about this topic on various forums, you'll find lots of assertions that the engine wasn't designed to be driven in city traffic, and that anyone who did so regularly was asking for trouble.

[joshsmith]

Interestingly after I tied my exhaust flap open on the valve hose thingy, the noise is worse on my car and lasts longer... hmmm....

[mtbscoTT]

So now I'm curious: do those of you who do have the problem often drive only a few miles, and do those of you who do not have the problem hardly ever drive short routes?

I do not have the noise and lots of my trips in the car are under 10 miles. My commute to work is 6 miles each way, and I go to lunch most days 6 miles or less roundtrip. Sorry for your problems but I don't think it's universal to the car.

[jpkeyzer]

I made a recording of the noise before I took the car in for the first time. I uploaded it here for those who want to sample it. This is what's captured:

Start, high idle: 00:08...
Low idle: 1:08...
Rattle: 1:17-1:20, 1:23-1:26

This rattle @ ~2k RPM reproduced nearly every time, and for several minutes, each time my car had sat idle for 2-3 hours. I really don't think I'm being too picky in this instance.

fourtunes - thank you for taking the time and effort to record this!

This will certainly benefit others (as a reference point) who may run into this issue.

I (and I am sure others) feel your pain - this is by no means acceptable!

I do not have the noise and lots of my trips in the car are under 10 miles. My commute to work is 6 miles each way, and I go to lunch most days 6 miles or less roundtrip. Sorry for your problems but I don't think it's universal to the car.

This is a valid point - start looking into your rights as they relate to the "Lemon Law".

After 2.5 months of TT-RS ownership and 2327 miles I have not experienced this problem.

[Marty]

Only 1 of my last 7 cold starts has reproduced this issue. And without carefully listening for it, you may not notice as it goes away within a minute.

So I question whether anyone's car truly is immune to this, or if folks haven't caught it happening yet...

Still patiently waiting to get it on video...

[neonova6]

So neonova6 and I do appreciate that for when we take ours in for the same repair.

I absolutely appreciate! I've been watching the thread like a hawk.

The thread on tts-freunde.de seems to be getting off track slightly with posters arguing about different types of oil.

But one poster claims that he used to have this problem, and that it went away when he started avoiding short drives (under 6 miles). Supposedly, an Audi expert asserted that short drives (which, according to Audi, is fewer than 30 miles) are problematic for this type of engine and should be avoided. Obviously, this is impractical, but the poster says that he hasn't had problems since extending the length of his commute to ~10 miles. A few other posters back this theory up, but offer no hard data.

So now I'm curious: do those of you who do have the problem often drive only a few miles, and do those of you who do not have the problem hardly ever drive short routes?

That's interesting, but I don't by it. My commute is 30+miles one way, with maybe 1-3 short trips that are less than 3 miles on the weekends. More than once, I've heard the issue after starting the car when leaving work, where the last trip was my commute. Overall, the majority of my trips are over 30 miles. And even after a shorter trips, I have not heard the issue. So personally, I've not seen a correlation between a shorter or longer trip making the sound occur more frequently.

I've been considering that route. But I decided to wait for the results for the timing chain replacements (i.e. another two weeks). Worst-case, the problem will continue to reproduce, but at least I'll have a new chain/etc. (I imagine the problem causes excessive wear, and after weeks of debugging, there's bound to be some fallout).

I hope that the service reps pay careful attention to any premature wear between the timing chain and all contact points.

I'm still itching to get a video too.

[Marty]

Caught it!

My car just reproduced the rattle (2nd time it made the noise out of 9 cold starts), but this time the car wasn't cold! The car had been sitting for about an hour, so the coolant temperature was at the 1/4 mark when I first started the car.

The noise wasn't quite as violent as it's been at its worst with a cold start, but you can definitely hear it. Here's a video (you can hear it steadily decrease throughout the video, until it's completely gone by the end):

[fourtunes]

I generally look at it the same way, but given that my engine has already undergone work on the intake and had its turbo replaced, the timing chain replacement/adjustments feel more like an appendix removal following open heart surgery. If the engine developed chronic problems as a result of any of these modifications, I feel there'd be ways to address that situation.

Besides, I still don't actually know for certain that the problem doesn't have potentially serious implications. I do want to know exactly what the problem is, at the very least to know how to avoid it reliably.

I just got off the phone with my service adviser.

Against expectations (mine, anyway), it looks like the ECU changes for the 2013 model year may have resolved the problem. Like I mentioned earlier, the firmware updates make adjustments to oil pressure settings. I haven't asked for details yet, but will do so later today.

The dealership seems reasonably confident that this really is a solution because of experience with the old S4, which apparently also had timing chain related rattling problems (though not quite as pronounced) after cold starts. Those problems were addressed in a similar manner.

I decided to reward the TT RS with an early oil change (since it's at the dealership anyway), but expect to pick it up later today. I'll keep you guys posted.

[Marty]

I just got off the phone with my service adviser.

Against expectations (mine, anyway), it looks like the ECU changes for the 2013 model year may have resolved the problem. Like I mentioned earlier, the firmware updates make adjustments to oil pressure settings. I haven't asked for details yet, but will do so later today.

The dealership seems reasonably confident that this really is a solution because of experience with the old S4, which apparently also had timing chain related rattling problems (though not quite as pronounced) after cold starts. Those problems were addressed in a similar manner.

I decided to reward the TT RS with an early oil change (since it's at the dealership anyway), but expect to pick it up later today. I'll keep you guys posted.

Did they mention when the 2013 changes would get rolled out?

[fourtunes]

Did they mention when the 2013 changes would get rolled out?

No, but I'll ask.

[Marty]

When it rains, it pours: here's a video of me reproducing the problem again this morning from a cold start (3rd time out of 10 starts). Even though it gets quieter as time goes on (the 2400 RPM resonance seems to die down), it still seems loud at higher RPM (though I didn't want to go higher while it was cold).

[fjork_duf]

Wow... sounds pretty noticeable. Thanks guys for pushing this. So far I haven't heard it yet...

[neonova6]

Well, that's some good news. Did they still replace the timing chain as well?

I just got off the phone with my service adviser.

Against expectations (mine, anyway), it looks like the ECU changes for the 2013 model year may have resolved the problem. Like I mentioned earlier, the firmware updates make adjustments to oil pressure settings. I haven't asked for details yet, but will do so later today.

The dealership seems reasonably confident that this really is a solution because of experience with the old S4, which apparently also had timing chain related rattling problems (though not quite as pronounced) after cold starts. Those problems were addressed in a similar manner.

I decided to reward the TT RS with an early oil change (since it's at the dealership anyway), but expect to pick it up later today. I'll keep you guys posted.

[fourtunes]

Well, that's some good news. Did they still replace the timing chain as well?

No. The service records indicate that the order was cancelled. Anyway, I have the car back now and it doesn't seem much worse off for wear. Fingers crossed...

As to the ECU update, it isn't clear if there's a plan to deploy it as a general update. If it really does end up solving my problem, you may want/need to work with your dealer to get the same update applied. I imagine that won't be a problem for anyone who visits the dealership I had my car serviced at.

[Marty]

No. The service records indicate that the order was cancelled. Anyway, I have the car back now and it doesn't seem much worse off for wear. Fingers crossed...

As to the ECU update, it isn't clear if there's a plan to deploy it as a general update. If it really does end up solving my problem, you may want/need to work with your dealer to get the same update applied. I imagine that won't be a problem for anyone who visits the dealership I had my car serviced at.

So did they actually update your ECU? Any mention of a version number on your paperwork?

[fourtunes]

So did they actually update your ECU?

Yes, the service record lists an ECM update.

[fourtunes]

So did they actually update your ECU? Any mention of a version number on your paperwork?

I'll double-check tonight, but I don't believe a specific version was mentioned. My service adviser always referred to it as the 2013 model year ECU update. I guess I ought to be able to tell with VCDS?

[Marty]

I'll double-check tonight, but I don't believe a specific version was mentioned. My service adviser always referred to it as the 2013 model year ECU update. I guess I ought to be able to tell with VCDS?

I'll poke around in VCDS later to see if I can find anything that resembles an ECU FW revision.

[Black BeauTTy]

Wow, mine doesn't make that noise at all. I'm glad you guys recorded it for all of us. I hope the ECU update solves it.

[Marty]

Wow, mine doesn't make that noise at all. I'm glad you guys recorded it for all of us. I hope the ECU update solves it.

Keep trying every morning! Mine sounds buttery smooth most of the time.

[Marty]

I'll double-check tonight, but I don't believe a specific version was mentioned. My service adviser always referred to it as the 2013 model year ECU update. I guess I ought to be able to tell with VCDS?

It's apparently very easy! Thanks to Arin@APR for providing the link on how to check the ECU software revision here: http://www.goapr.com/support/boxcode.php



I'm curious what your version # is now, fourtunes. APR mentioned that they've seen TT-RS software revisions of both S0010 and S0020 already. Maybe some folks' cars are already shipping with revised S0020 software.

[fourtunes]

It's apparently very easy! Thanks to Arin@APR for providing the link on how to check the ECU software revision here: http://www.goapr.com/support/boxcode.php



I'm curious what your version # is now, fourtunes. APR mentioned that they've seen TT-RS software revisions of both S0010 and S0020 already. Maybe some folks' cars are already shipping with revised S0020 software.

That's easy enough. I'll check tomorrow morning - there's no mention of the version on the service record. I head meant to check VCDS (look for fault codes, etc.) after work, but after more than a month with a 2 liter engine, I had to spend some quality time with the RS, first.

[Marty]

That's easy enough. I'll check tomorrow morning - there's no mention of the version on the service record. I head meant to check VCDS (look for fault codes, etc.) after work, but after more than a month with a 2 liter engine, I had to spend some quality time with the RS, first.

Just checked with VCDS: my car is running rev 0020. I hope your rev is higher.