"Chugging" sound from Turbo Inlet

[Rastboostin]

Hey Guys,

I have a 08 A4 Quattro, 89k miles on it. Car is in great shape and the engine runs like a champ. I'm in the chicago area, and it has been the winter from hell. My 2nd PCV was going bad and causing my rpms to bounce so I replaced it with a catch can from RAI. This fixed the problem, but since I've installed it (I think his is when it started, but I didn't actually notice it until a week later), I hear this kind of deep "chugging" sound at idle.

The sound in the video is kind of loud, so prepare your volume so your ears don't explode



You can hear the "chugging" once I get over to the turbo side of the engine. It never made this sound before.

The car is very well maintained. I'm always on point with oil changes and regular mainetnance. The breather tube from the Turbo to the VC was replaced with a new one about a month ago. The car drives just as smooth under acceleration and when engine breaking and Im still peaking at 19 PSI and holding at 16. I haven't gone all out WOT just because the weather has been so crappy here, and I'm due for new clutch. But yeah, I don't think it's metal on metal vibrating or anything, and strangely enough, SOMEtimes, I don't hear it and my idle is smooth again.

I know it's been very cold around here lately so there is that, but I did have the car hooked up to VCDS on Saturday and there were no codes or anything to be a red flag.

The sound is coming from the Carbonio airbox it sounds like, but that could be coming from the inlet or (hopefully not) the turbo itself. Is this just a side effect of having a block off plate/catch can? The catch can is definitely working as it should as I have drained it once already.

Any thoughts on where I should start or any advice is greatly appreciated.

[Rastboostin]

I mean, I guess it could be some metal hitting plastic? But when I went under the car, I couldn't figure out what it might be. The other thing is that I can really feel those vibrations in the gas pedal and the shifter. Keep in mind though, it HAS been -10 to 30 degrees for the past 2 months :(

[Der Konig]

The "chugging" you refer to, are you talking about that sound that sounds like a kids bike with a playing card in the spokes? So hard to diagnose sounds through video, completely changes the sound.

[Rastboostin]

At about 17 seconds into the video, as soon as my camera fixates on the carbonio. You can hear it have kind of a deeper tone to it, but if you're listening to it on a phone speaker or laptop speakers, you probably won't hear it well. That normal clicking sound is the fuel injectors right? or something?

My phone is crazy sensitive to picking up sounds, like my grunt to get my fat ass out of the car haha.

[Der Konig]

Yeah the clicking is normal, I can't hear it on my laptop I guess. I'll listen again but I get a deep bass sound sometimes that I assumed was normal. Never gave it much thought, will try and check it out tonight and see if I can hear it better.

[Jake@JHM]

If you have some one rev it, does the noise get louder?

[SwiftA4]

From the video it honestly sounds like plastic clanging together. As Jake mentioned above, does it get louder when someone revs the engine? Does it go away after the car is warmed up?

As you mentioned, and from what I can tell in the video, it seems like its coming from the carbino. Did you check to make sure everything is tightened down? If you put your hand on the carbino, can you feel any rattle in it or does the sound calm down?

[Jake@JHM]

If it is something happening internally it will be audible from the intake since that is essentially a tunnel leading inside the engine.

OP, what all did you touch while installing the catch can? Is the can rattling on anything with the engine vibrations?

[08 classic]

That sound is from the rear PVC tube check valve. Once you give it gas it goes away. Its normal I wouldn't worry about it, although some have removed the valve inside the PVC tube.

[aluthman]

I've got the same sound. I should pull the check valve out one of these days...

[Rastboostin]

That sound is from the rear PVC tube check valve. Once you give it gas it goes away. Its normal I wouldn't worry about it, although some have removed the valve inside the PVC tube.

I think you may be on to something. I let the car warm up nicely this morning, the sound was there at the idle. I had my roommate give it some gas up to about 3k and yeah, the sound DOES go away. As I said before, it still pulls nicely, since I'm still on the K03 it spools in the low 2ks so I am able to get into boost despite the shit show mother nature has thrown at us.

If it is something happening internally it will be audible from the intake since that is essentially a tunnel leading inside the engine.

OP, what all did you touch while installing the catch can? Is the can rattling on anything with the engine vibrations?

The Catch Can install was pretty normal. I'd done my PCV before, so this was basically the same thing. I'm wondering if maybe it's something with the block off plate and that rear tube 08 classic was talking about?

That's why I was concerned to begin with. My first thought was maybe the box/heat shield wasn't secured enough, but I checked it's positioning and bolts and it seemed fine. But you're right. It seems to be coming from within the box/turbo inlet, which made me worry that something internal might be wrong with the turbo or something. But, considering how nicely it still does pull, and that it IS completely smooth, 08 Classic might be right.


But if you guys seem to think it should be okay, it puts me at ease. I just needed another opinion. Think it might be worth replacing that tube? It's still the original one that came with the car. It's this guy, I believe: http://www.ecstuning.com/Audi-B7_A4-...oses/ES281099/

Thanks!

[mr shickadance]

seems like with the replacement of the PCV that you could have some oil in your I/C's.

Maybe try and drain that out, could just be a decent sized oil puddle within both or one of the i/c making a glug noise? idk i would imagine the boost would push it through but who knows

[Rastboostin]

By I/Cs do you mean my side mount intercoolers? Sorry, not familiar with I/C. If you are referring to them, I have a FMIC so I can pop off the piping when it gets a bit warmer to see if anything is collecting in there.

[Jake@JHM]

I think you may be on to something. I let the car warm up nicely this morning, the sound was there at the idle. I had my roommate give it some gas up to about 3k and yeah, the sound DOES go away. As I said before, it still pulls nicely, since I'm still on the K03 it spools in the low 2ks so I am able to get into boost despite the shit show mother nature has thrown at us.



The Catch Can install was pretty normal. I'd done my PCV before, so this was basically the same thing. I'm wondering if maybe it's something with the block off plate and that rear tube 08 classic was talking about?

That's why I was concerned to begin with. My first thought was maybe the box/heat shield wasn't secured enough, but I checked it's positioning and bolts and it seemed fine. But you're right. It seems to be coming from within the box/turbo inlet, which made me worry that something internal might be wrong with the turbo or something. But, considering how nicely it still does pull, and that it IS completely smooth, 08 Classic might be right.


But if you guys seem to think it should be okay, it puts me at ease. I just needed another opinion. Think it might be worth replacing that tube? It's still the original one that came with the car. It's this guy, I believe: http://www.ecstuning.com/Audi-B7_A4-...oses/ES281099/

Thanks!

Did your Catch Can not replace that breather hose? I know my 034MS CC does. Do you want to post a picture of your install?

Jake

[thenofjboy]

That sound is from the rear PVC tube check valve. Once you give it gas it goes away. Its normal I wouldn't worry about it, although some have removed the valve inside the PVC tube.

This. Once you remove the check valve, the chugging noise will go away. IIRC it has something to do with the catch can once its Installed. Search around, It was talked about a before

[Rastboostin]

This. Once you remove the check valve, the chugging noise will go away. IIRC it has something to do with the catch can once its Installed. Search around, It was talked about a before

Thanks, and yeah, I only post threads after Id done some searching. I just don't think I was able to come out with the right description to get the results I was looking for, so I figured I'd post a video. Everything I came up with were people saying they had symptoms of a failing PCV and check for boost leaks, etc.

[Rastboostin]

Did your Catch Can not replace that breather hose? I know my 034MS CC does. Do you want to post a picture of your install?

Jake

It did not, here's what the kit came with:



It also looks like the 034 one doesn't replace it either, unless they've changed what comes with the kit from what's in their pic:

http://store.034motorsport.com/catch...-2-0t-fsi.html

Does anyone know of a hose that I could buy to replace that rear breather hose that would eliminate the chugging sound? Or is it easy to cut out the check valve in it?

[Rastboostin]

OOOOkayyy, I think I've got it figured out. There may have been some confustion, because on the VW forums, they refer to it as the "rear breather tube" or "rear check valve" when referring to the metal breather tube that connects the turbo to the valve cover. That guy seems to be the culprit. I just found this DIY off of Golf MKV which I'll try tonight and post the results.

Edit: THIS diy http://www.golfmkv.com/forums/showthread.php?t=60428

It's been a productive day at the office :) Thanks for the help! I just needed some feedback to get pushed in the right direction. I'll post later

[Jake@JHM]

OOOOkayyy, I think I've got it figured out. There may have been some confustion, because on the VW forums, they refer to it as the "rear breather tube" or "rear check valve" when referring to the metal breather tube that connects the turbo to the valve cover. That guy seems to be the culprit. I just found this DIY off of Golf MKV which I'll try tonight and post the results.

It's been a productive day at the office :) Thanks for the help! I just needed some feedback to get pushed in the right direction. I'll post later

Haha sounds good! That kit you posted above does indeed replace that breather tube you linked prior.

Jake

[Rastboostin]

Haha sounds good! That kit you posted above does indeed replace that breather tube you linked prior.

Jake

Yeah the silicone ones are for the plate, that just replaces the 1 short plastic breather tube that connects from the valve to intake manifold. The one I linked from ECS was for that longer one that connects to the last opening on the block off plate towards the back of our engines. That's where I was getting confused. I thought we were saying that THAT hose has a check valve that needed to be removed (rear check valve, duuhh :) ) When it's actually the Metal one that we have up at the front. The GTIs just have it at the back since they are Transverse.

I'll let you know my results!

[brothaug]

OOOOkayyy, I think I've got it figured out. There may have been some confustion, because on the VW forums, they refer to it as the "rear breather tube" or "rear check valve" when referring to the metal breather tube that connects the turbo to the valve cover. That guy seems to be the culprit. I just found this DIY off of Golf MKV which I'll try tonight and post the results.

Edit: THIS diy http://www.golfmkv.com/forums/showthread.php?t=60428

It's been a productive day at the office :) Thanks for the help! I just needed some feedback to get pushed in the right direction. I'll post later

Keep us posted on this. I get a similar sound just after starting when its cold outside (<40F). it's only there at idle, goes away if I rev above 1500rpm, and once the car warms up its gone completely.

[Axis]

I have the noise diagnosed here when starting the car when cold, goes away when warm or when raising the rpm but I have an oem PCV replaced by Audi last year. I was about to replace my breather tube with part #06D 103 213G since I was told it was a "revised" part but when about to change it I noticed I already had that "revised" part. What could cause that?

Sorry for the thread jack didnt want to make a new thread for that.

[RAudiB7A4]

I installed the BSH PCV revamp kit last week and my engine is making this exact "chugging" noise as well. I noticed because the noise is actually louder than my turbo-back exhaust with a test pipe at idle. I also have the Carbonio, which I'm sure makes it that much louder.

Guess I'll have to look into removing this check valve as well. As long as it won't hurt anything.

[Jake@JHM]

Hmm.. I am not getting this sound and I have the 034MS CC, and a cone filter on my MAF for that sweet sound.

Care to post a pic of your installation?

[thenofjboy]

Thanks, and yeah, I only post threads after Id done some searching. I just don't think I was able to come out with the right description to get the results I was looking for, so I figured I'd post a video. Everything I came up with were people saying they had symptoms of a failing PCV and check for boost leaks, etc.

heyooooooo sorry didnt mean to seem like you didnt search. its the rear PCV, the metal tube off the VC, like you said in the post below. I removed the check valve with a screwdriver and its good to go.

btw, how is your catch can in the winter? esp since you are in Chicago. Has it frozen yet?

[08 classic]

If you leave the valve in, it will be fine, but will just make that noise when at idle. Now some cars will make that sound and some will not, thats because earlier 2.0t engines rear pvc breather tube did not have this valve in it. My car... well I just left it ...gives it character lol.

[Jay-Bee]

That sound is from the rear PVC tube check valve. Once you give it gas it goes away. Its normal I wouldn't worry about it, although some have removed the valve inside the PVC tube.

This noob is spot on.

Mine made a lot more noise after my AEM intake was in.

[Rastboostin]

Unfortunately I wasn't able to remove the check valve last night. We got his with some pretty bad snow, and it's still coming down. I then have to go to Pennsylvania tomorrow morning for work so this thing will have to wait until I'm back next week :( I'll still post my update when I'm back.

Hmm.. I am not getting this sound and I have the 034MS CC, and a cone filter on my MAF for that sweet sound.

Care to post a pic of your installation?

Here's my install:

heyooooooo sorry didnt mean to seem like you didnt search. its the rear PCV, the metal tube off the VC, like you said in the post below. I removed the check valve with a screwdriver and its good to go.

btw, how is your catch can in the winter? esp since you are in Chicago. Has it frozen yet?

All good my friend. So far I've had no problems with it. A friend told me that if your use your heat/AC a lot, you'll need to empty it more frequently because of the increased amount of condensation that comes in. I've emptied it twice and it's definitely working as it's supposed to. So far, I've had no issues with the lines freezing. I'm sure that some of the nastiness gets frozen in them, but the lines are big enough that it wouldn't clog them with crap, and when the car warms up, it would melt and go into the can

[SwiftA4]

Rastboostin, keep us updated when you finally get around to removing the valve. I'm now getting the same noise at cold idle, and just want some more confirmation that it is actually the check valve before I go removing it.

Are there any downsides to removing the valve? I'm stock with no catch can and OEM PCV.

[Rastboostin]

Reviving a dead thread. Sorry for the delay, but I FINALLY got around to doing this this weekend. Funny enough, I actually had this breather hose lying around in my closet from when I had originally done my PCV update and mistakenly ordered the wrong kit: http://www.ecstuning.com/Audi-B7_A4-...ssions/ES8583/



I swapped out my breather hose with the one from the link that has no check valve and the sound went away. It was kind of driving me crazy. Even just sitting at a traffic light I would just hear that noise. But now it's gone completely. The engine just has a nice purr. I haven't noticed any performance changes or anything at all thus far. I put on about 300 miles this weekend after having it done and it's been fine.

[Rastboostin]

Been driving with this fix on now for a few weeks. Still 0 issues. Nice smooth engine that doesnt have an embarrassing chugging sound that my friends would ask "what is that?" anymore.

Just an update :P