2.0T VVT Noise

[Wolfman4584]

For a few months now I've been battling a noise from the VVT system on my 2013 A4 along with a P0341 code and EPC light. The noise goes away when I unplug the camshaft adjuster magnet so I know for sure the noise is coming from the VVT system. So far the car has gotten new chains, guides, and tensioners. Then it got a new camshaft bridge, intake cam, the valve in the end of the cam, camshaft position sensor, and camshaft adjuster magnet. After that didn't fix it I had the oil pickup tube replaced in case it was clogged which again didn't fix the problem. The shop that did some of the work after I got tired of messing with it wants to try replacing this check valve(https://www.ecstuning.com/b-genuine-...BoCU7YQAvD_BwE) in the cylinder head next since they found one report of someone with the same noise where it was caused by this check valve being stuck. However since you have to remove the cylinder head to replace the valve it's a pretty expensive repair and no one can guarantee that it's for sure the problem. Has anyone else run into an issue with this check valve on there 2.0T or have any mechanics out there seen this problem?

[Theiceman]

got a video of the noise ????

there is a pretty extensive thread on the VVT system you might want to read over under the troubleshooting P0016 thread..

sounds like you have changed everything outside of the phaser... have you tried disassembling it and cleaning it ? pieces of your old screen might be jamming things up . when you changed the cam bracket was the screen there or missing ?

are you saying at idle it does it then you unplug the solenoid then it goes away ? or are you unplug it , go for a drive and then dont hear the noise ?? i think more info or a video might be helpfull.

may have nothing to do with VVt at all .. possibly just a noise when car runs at advanced timing . ? i think the video will tell us lots.

[Wolfman4584]

got a video of the noise ????

there is a pretty extensive thread on the VVT system you might want to read over under the troubleshooting P0016 thread..

sounds like you have changed everything outside of the phaser... have you tried disassembling it and cleaning it ? pieces of your old screen might be jamming things up . when you changed the cam bracket was the screen there or missing ?

are you saying at idle it does it then you unplug the solenoid then it goes away ? or are you unplug it , go for a drive and then dont hear the noise ?? i think more info or a video might be helpfull.

may have nothing to do with VVt at all .. possibly just a noise when car runs at advanced timing . ? i think the video will tell us lots.

Here is a link to the video of the noise https://youtu.be/mcPjgbv2lp8 the noise is louder in person but can easily be heard in the video.

Is the phaser this piece(https://www.ecstuning.com/b-genuine-.../06h109257c/)? If so that was replaced as well. When I took off the original cam bracket the screen was still intact and looked fine but I removed it anyways and reinstalled that cam bridge. Then after I took the car to the shop they tried replacing the cam bridge with a new one to see if it would make a difference which it didn't.

The noise never happens at idle and seems to only be between ~1700 and ~3000rpm both when revving up and revving down. However if I unplug the solenoid the car revs and drives fine and never makes the noise. Even when the noise is present it seems to drive ok other than sounding horrible.

[Theiceman]

okay just as i thought ... the reason the car does not do it at idle is because it is retarded... I believe this has NOTHING to do with VVT per se. i think you are following a red herring . I dont think your problem statement is " my VVT is bad" . i think your problem statement is " my engine produces noise and throws a code while running with valve timing advanced".

VVT is putting you in the mode that is causing the problem . But is not necessarily the route cause of the issue. you have to look at what else is affected when you advance the cams. what else does the car do while operating in that mode. ?

BTW your link didnt work .. but the phaser is what the VVT valve goes into.

edit : i just noticed on the B8 the phaser or " camshaft adjuster unit" is attached to the intake cam.

was the intake cam you used brand new and replaced for this specific issue ?

also in your video you keep revving it .. dont do that .. increase revs and hold it there . i want to see if the noise persists while at the higher RPM or is it only doing it as you try to get there .. ie slowly increase rpm and hold it at say 3 K for 10 seconds.

[Wolfman4584]

okay just as i thought ... the reason the car does not do it at idle is because it is retarded... I believe this has NOTHING to do with VVT per se. i think you are following a red herring . I dont think your problem statement is " my VVT is bad" . i think your problem statement is " my engine produces noise and throws a code while running with valve timing advanced".

VVT is putting you in the mode that is causing the problem . But is not necessarily the route cause of the issue. you have to look at what else is affected when you advance the cams. what else does the car do while operating in that mode. ?

BTW your link didnt work .. but the phaser is what the VVT valve goes into.

Not sure what happened to the link from ECS but oh well. The phaser I believe came as part of the cam so it was replaced along with the intake cam.

As far as what else is affected when you advance the cams I'm not sure but I'm definitely open to checking other items. I've tried listening to different parts of the motor for the noise and it's hard to pinpoint exactly where it comes from but I've also been going off the assumption of it being directly part of the VVT.

I know the shops reasoning behind that check valve was if it was preventing enough oil pressure from getting to the cam it might not be adjusting correctly or causing the cam to go back and forth between advanced and retarded however last time I pulled logs with OBDEleven I didn't notice anything like that happening.

[Wolfman4584]

2nd reply based on your edits...

The intake cam was a brand new genuine Audi part bought from ECS. The new camshaft adjuster valve that screws into the end was also a brand new Audi part purchased from a local Audi dealer.

I can take a new video tonight holding it at 3K since the car is at home and I'm at work. I want to say the noise goes away when holding it steady since it happens while accelerating and also when the motor decelerates when I push the clutch to shift but I never remember hearing it once I'm up to speed and cruising steady even if the RPM's are sitting in the range where the noise occurs.

[Theiceman]

this is an interesting one... i wonder if oil pressure i having trouble keeping up ? then replacing that check valve might make sense. unless its oil pressure overall ...
as you likely know these cars dont have oil pressure sensors so you can monitor it . . they just have switches that trigger at a certain level.

i wonder if they did the pressure check for this check valve while they had the bracket off.. i would assume they think it is stuck open .. as if it was stuck closed you would never advance the cam.

Even if it were stuck open , would be hard to believe it would affect it beyond initial start.

[Wolfman4584]

this is an interesting one... i wonder if oil pressure i having trouble keeping up ? then replacing that check valve might make sense. unless its oil pressure overall ...
as you likely know these cars dont have oil pressure sensors so you can monitor it . . they just have switches that trigger at a certain level.

The motor acts like it has oil pressure and I've never seen an oil pressure light turn on while the car is running but I suppose it could be just above whatever threshold triggers the light but maybe still low enough to cause these issues?

[Wolfman4584]

This thread is one of the 2 people I know of where the check valve ended up being the issue if it helps at all. The only other car I know of is the one that came up in the repair software used by the shop I had my car at so I don't have any info on what all was replaced for that person.

https://www.golfmk6.com/forums/showthread.php?t=116989

[Wolfman4584]

this is an interesting one... i wonder if oil pressure i having trouble keeping up ? then replacing that check valve might make sense. unless its oil pressure overall ...
as you likely know these cars dont have oil pressure sensors so you can monitor it . . they just have switches that trigger at a certain level.

i wonder if they did the pressure check for this check valve while they had the bracket off.. i would assume they think it is stuck open .. as if it was stuck closed you would never advance the cam.

Even if it were stuck open , would be hard to believe it would affect it beyond initial start.

I don't think they did the pressure check for the valve since at the point where it was last apart I'm pretty sure they didn't even know the valve was a possible issue. I thought about doing the pressure test myself but haven't figured out how I can pressurize the oil passage since I can't thread an air fitting into it or anything. I also assume that they think the valve is stuck open but like you said I wouldn't think it would affect it beyond initial start since once the motor is running it should have a steady flow of oil going up to the cam and not need the valve to close at all. I suppose it's possible the valve is stuck partially open like in the post I referenced from the golf forum.

[Theiceman]

yes i think you are on a logical path .. when i said oil pressure i meant check valve stuck partially open so oil pressure can not reach adjuster .. car does not monitor there.. could be good in rest of the engine..

oil pressure overall you would think is okay if you have never seen a warning..

can you hold a rubber nozzle against that port .. but of course that is not ideal..

[Theiceman]

just read that other thread and that is exactly where we were going ... not enough oil pressure to the vanes of the adjuster .. that is why i wanted you to put at at an RPM and leave it . I am suspecting once at rpm it is fine as the oil pressure can catch up. bet if you increase the rpm very very slowly it will not do it as their is enough oil getting by to keep up .

i think if you were to scope the crank and cam pulses you might see the cam pulse not instantly jumping ahead , but lagging where it is supposed to be until the rattle stops. and the cam pulse catches up ( cam advances )
i think you definitely have oil starvation in that circuit if the tests i asked you to do check out. Then its just a matter of where.. and that check valve is looking like a likely place as any.

that check valve could also close completely , but not open all the way like in that other post. then the pressure test would tell you nothing.

I guess the small bit of good news is pulling head is not that bad if that is all have t be done .. head, valve cover, turbo and intake all come off as one unit. it is a full day maybe even two for a professional mechanic , but its not like a complete engine rebuild.

[Wolfman4584]

yes i think you are on a logical path .. when i said oil pressure i meant check valve stuck partially open so oil pressure can not reach adjuster .. car does not monitor there.. could be good in rest of the engine..

oil pressure overall you would think is okay if you have never seen a warning..

can you hold a rubber nozzle against that port .. but of course that is not ideal..

I was wondering if I could do it with a rubber nozzle. Assuming I found one the right size I could probably push it against the oil passage enough to "seal" it. Then I would just have to rig up some sort of pressure gauge on my airline to see if it dropped I guess.

[Wolfman4584]

just read that other thread and that is exactly where we were going ... not enough oil pressure to the vanes of the adjuster .. that is why i wanted you to put at at an RPM and leave it . I am suspecting once at rpm it is fine as the oil pressure can catch up. bet if you increase the rpm very very slowly it will not do it as their is enough oil getting by to keep up .

i think if you were to scope the crank and cam pulses you might see the cam pulse not instantly jumping ahead , but lagging where it is supposed to be until the rattle stops. and the cam pulse catches up ( cam advances )
i think you definitely have oil starvation in that circuit if the tests i asked you to do check out. Then its just a matter of where.. and that check valve is looking like a likely place as any.

I'll try to do these tests tonight using OBDEleven and see what the cam pulse does. Hopefully it reacts the way you're expecting and it gets me closer to fixing the problem!

[Theiceman]

I'll try to do these tests tonight using OBDEleven and see what the cam pulse does. Hopefully it reacts the way you're expecting and it gets me closer to fixing the problem!

i dont think OBD11 acts like a try scope .im not sure cam and cranlk pulses are in the data stream .. you would need a real oscilloscope ..

my next investment is a pico scope. My old Hameg 20Mghz scope looks like something out of the dark ages now..

[Wolfman4584]

i dont think OBD11 acts like a try scope .im not sure cam and cranlk pulses are in the data stream .. you would need a real oscilloscope ..

my next investment is a pico scope. My old Hameg 20Mghz scope looks like something out of the dark ages now..

Hmm ok that will make it harder then since I don't own a scope so I will have to try and find someone with one.

[Theiceman]

Hmm ok that will make it harder then since I don't own a scope so I will have to try and find someone with one.

i think really that would confirm what we already know .. i think if you do the tests tonight we will know ... open the throttle a little wait , a litle more wait .. i think it will confirm everything.
But yeah a pressure gauge on that cam bracket while running and compare against a known good would be icing on the cake,,

[Wolfman4584]

Ok I played around with the car some tonight and here is what I found.

1. When the motor is cold there is no noise or at least very little noise.
2. When driving the noise starts around 1500 rpm and stops a little over 3000 rpm.
3. The noise is most noticeable when you first push the clutch to shift assuming you're in that rpm range or if not then as the motor drops into that range. However when the rpms are dropping the noise only happens for a second or two and then stops. I'm assuming this is because the cam timing quickly returns to the normal position when no load is on the motor.
4. When both driving or sitting still in neutral the noise is there while holding the rpm's steady. This video is when they are held at 2000 https://www.youtube.com/watch?v=34WnEUSd0qA and this video is holding it at 3000rpm https://www.youtube.com/watch?v=cjFxYygaLzY
5. The noise seems to happen regardless of how slow or fast you rev the motor.
6. When driving if you accelerate over about 3000rpm and keep the rpms up you can accelerate continuously without any noise and the car seems to run fine and pull like normal.
7. When the EPC light flashes on for a second a little under 2000rpms you sometimes get a stutter or hesitation but only for a split second.

[Theiceman]

yeah thats a trick one to be sure .. so it sounds like at the higher rpm it just cant keep up...

This is a tough call to be sure whether to spend the bucks to get this addressed.

I guess you could leave the solenoid unplugged but you will never have advanced timing. I guess that means less performance at higher RPM maybe ? or it may just be a pollution control thing ? who knows.

guess if the cam bracket didn't fix it ( there is a check valve in there also ) the one in the head is the next logical choice .. admittedly expensive gamble though.

[Wolfman4584]

Yep it's definitely an expensive gamble at any shop. It seem's like the next logical choice unless the problem isn't related to oil at all but not sure how to figure that out. I don't have much free time to work on it currently or I would attempt to do the check valve myself but it would take a long time with my limited free time.

I've also thought about just leaving the solenoid unplugged permanently but wasn't sure what long term effects that would have on the car. I'm also slightly worried that the cam will wear out sooner than normal if there is very little oil making it up there.

[Theiceman]

good point .. i did not look closely enough when i had my head off to see if that was the ONLY pathway to the head , or whether its a dedicated pathway to the cam bracket for the VVT system.

[Wolfman4584]

good point .. i did not look closely enough when i had my head off to see if that was the ONLY pathway to the head , or whether its a dedicated pathway to the cam bracket for the VVT system.

I want to think there would be other pathways as well but I'm not sure. Any idea how many hours a shop charges for a head gasket on these motors? I'm thinking it should be the same amount to replace the check valve.

[Theiceman]

I want to think there would be other pathways as well but I'm not sure. Any idea how many hours a shop charges for a head gasket on these motors? I'm thinking it should be the same amount to replace the check valve.

i have no idae .. mainly because the head gaskets are iron clad on these babys , i have never heard of one failing. i would think pretty well a whole day though.

[Wolfman4584]

Guess I'll have to call around and get some prices on it then. If any Audi mechanics local to me are looking for side work or if anyone knows of a good Audi shop in the Northeast Ohio area feel free to comment and let me know.

[Swamp1]

Guess I'll have to call around and get some prices on it then. If any Audi mechanics local to me are looking for side work or if anyone knows of a good Audi shop in the Northeast Ohio area feel free to comment and let me know.

hi did you manage to sort this issue out as I have the same thanks

[Theiceman]

hi did you manage to sort this issue out as I have the same thanks

Last time he posted here was 18 months ago. He was just here to get his car fixed and left.

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