Rattle from the back of the supercharger

[bgoetz]

I will start by saying I really appreciate all of the info from this forum, but I am not looking for wild guesses here, I am looking for someone who has some type of first hand experience with an issue like this.

I have had a rattle from the back of the supercharger, it is clearly coming from the intake area of the supercharger. It sounds really gravelly and I can’t imagine Audi intended the car to sound this way. Overall the car seems to run great and pulls strong, just sounds like a rock in a slow motion garbage disposal by the supercharger. Admittedly, I noticed it when I bought the car and didn’t think much of it, figuring whatever it was would hopefully be an easy fix or nothing more than an annoyance.

You have to really listen to hear it over the injectors and valves

Update: using a stethoscope it seems the sound is coming mostly from the throttle body area.

https://youtube.com/shorts/hhO1Mfychmc?feature=share

[5moremins]

Sounds like the same thing I have though I was never able to pinpoint the source. There was another thread about this and the consensus was this is normal. Does it only happen while in park?


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[Cerbera9]

I had a noise like this and it was the two needle bearings on the SC rotors. This causes the rotors themselves to move as they spin and cause wear & scoring the SC body and rotors themselves.

[bgoetz]

Thanks guys! I am not sure if it does it outside of park, but it does still do it when I increase rpms.

If it is the bearings wearing and the rotor of the SC as described that would be slightly concerning as it seems that could make metal that might end up in the engine.

To me it seems odd that I can isolate it to the throttle body, but maybe the sound is magnified and that acts like the outlet for the sound. The only other thing I would think it could be is a timing chain tensioner but I can’t hear any sound when placing it on the timing chain cover and would think that I would really hear it from there.

[bgoetz]

Is there anything in the TB area that could make the noise? Does anyone have an engine diagram of this area that shows all of the components? I know the PVC is under the SC, but I doubt that could make the sound. I can’t think of anything inside of the throttle body itself and since it seems to still do it when increasing rpm I would think that would rule out the throttle body.

I don’t want to be paranoid about a noise, but don’t want to ignore something that will cost me big in the long run, like a SC issue that isn’t completely internal to the SC or the timing chain.

[lacroixd]

subbed

[Izzyz28]

My supercharger rattles, it always has. Seems to become more noticeable if I run a shitload of water/meth through it, then gets quieter after a while. If you want to pinpoint the bearings, have a buddy hold the engine at 4K or so and spray a bunch of WD-40 through the TB to coat the bearings and see if the sound goes away or changes.

[chrismadson]

My supercharger rattles, it always has. Seems to become more noticeable if I run a shitload of water/meth through it, then gets quieter after a while. If you want to pinpoint the bearings, have a buddy hold the engine at 4K or so and spray a bunch of WD-40 through the TB to coat the bearings and see if the sound goes away or changes.

Wouldn’t that wash away any sort of grease that is present in the bearings? It may quiet it for a moment, but make it worse in the long term.


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[bgoetz]

My supercharger rattles, it always has. Seems to become more noticeable if I run a shitload of water/meth through it, then gets quieter after a while. If you want to pinpoint the bearings, have a buddy hold the engine at 4K or so and spray a bunch of WD-40 through the TB to coat the bearings and see if the sound goes away or changes.

Ah, so are you saying the bearings are right inside of the TB? I guess I thought the bearings were sealed inside of the supercharger and submerged in oil.

[Izzyz28]

Ah, so are you saying the bearings are right inside of the TB? I guess I thought the bearings were sealed inside of the supercharger and submerged in oil.

There are bearings and the gear drive assembly at the front, and bearings at the rear of the rotors just past the TB. In regards to "washing the grease", if it's making noise already, what harm is some WD-40 going to do? I'm pretty sure gallons of methanol constantly going through there are a bit more detrimental to lubrication.

[bgoetz]

Ok, so the sound from the TB does seem to point towards the bearings and/or the rotors in the SC. And if I am following there is the potential for the supercharger to shit metal into the engine if things are too messed up with it.

[Mfryman1]

I might be able to assist. I have rebuilt my SC. There is 2 needle bearings in the back that do indeed hold the rotors where they need to be not allowing the rotors to hit each other.
20210321_160322.jpg
See the interior with one needle bearing installed and one not.
What you are hearing is scary as if the rotors are hitting each other the black coating will wear off and you are correct damaging the rotors and it is possible to throw aluminum into the cylinders. If mine were making that noise I would not drive it!
I noticed a noise coming from the nose or front of mine and it sounded like a "dry bearing noise" I ordered a rebuild kit for the TVS 1320 from superchargers online, and tore it apart and replaced all the bearings. It is tricky to get the needle bearings out but if you decide to tackle the job I would be glad to talk you through it.
To make sure it is not a timing tensioner issue just take the SC belt off and start it and see it all is quite. Might throw a few codes but just unhook the battery to reset. It will run a little rough for the next couple hundred miles but will relearn all the mixtures etc.
Cost for the bearings is less than 200.00 with the oil for the front. If the rotors are indeed damaged I know there are ways to get them fixed but it would not be cheap. Taking it apart to look is just nuts and bolts and dealing with the stinky SC oil from the front nose assy.

Below circled is where you would see the rotor damage.
20210509_101921.jpg

[Mfryman1]

Also remember the coupling or adaptor on the nose drive between the pulley and the drive gears sometimes are made of plastic and they also fail, but this would not cause that noise in the back as it would be in the front. Mine was a good spring adaptor that is indestructible.

[Mfryman1]

Also remember the coupling or adaptor on the nose drive between the pulley and the drive gears sometimes are made of plastic and they also fail, but this would not cause that noise in the back as it would be in the front. Mine was a good spring adaptor that is indestructible.

BTY the needle bearings are packed with a special grease and have a lip seal on the exposed side to the rotors. New ones come pre-packed with grease. No oil lubrication on the back bearing just
the front and it is on a closed system with 150 ML of special oil for the front roller bearings. No needle in the TB but they are right close to it so the would would be at the TB.

[Mfryman1]

sorry the sound would sound like that at the TB...

[bgoetz]

Thanks that is super helpful! My guess is that it is not the belt tensioner as that would be in the front. I was thinking of the possibility of the timing chain tensioners or guides which is in the rear, but removal of the belt wouldn’t verify that. Based on what you provided I am going to speculate that it is the needle bearings and the rotors making contact but will try some sort of a verification before going all in and pulling the supercharger.

Could you provide a link to the rebuild kit? Also how long did it take to do (I am fairly mechanical and have access to a lot of tools and lift). I would probably do the PCV and maybe walnut blast the intake while I have it off.

If you have any ideas of how to verify that this is what it is without pulling the SC let me know.

[sepheroth86]

Easiest way to check bearings for play would be to remove the blower and put your fingers between the rotors while turning the pulley with your other hand, the bearings usually will have some deflection in them (you may feel movement or hear a noise).

I have watched the guys at ZZP do this over the years when inspecting blowers on L67 or LSJ cars.

[bgoetz]

Easiest way to check bearings for play would be to remove the blower and put your fingers between the rotors while turning the pulley with your other hand, the bearings usually will have some deflection in them (you may feel movement or hear a noise).

I have watched the guys at ZZP do this over the years when inspecting blowers on L67 or LSJ cars.

Yeah so at that point I might as well change the oil and consider a rebuild and change the PCV because I am 1/2 way there.

[sepheroth86]

Does removal of this plate allow one to reach the output flange of the blower?




You need to access the output flange as seen in the picture below.

[bgoetz]

I wonder if it could be something with the bypass valve? That is a very close location and if that is flapping around I imagine it would make a sound.

That drawing is helpful though because I can use that as a guide to listen with my stethoscope.

And yeah if I can inspect by removing the plate that would make checking for play easier as well.

[bgoetz]

Also if it were the bypass valve the fact that when increasing rpms in park the sound stays the same would make sense because I imagine the SC is in bypass when it isn’t under any load, but maybe I am wrong on that. So under load the bypass is closed and maybe doesn’t flap.

I think another way to diagnose the issue is to listen to in when increasing rpm because if it is the needle bearings I would expect a noticeable change where as if it were the bypass maybe not so much as it might just have a bit more air moving past it, but nothing more.

[Fresh.S4]

i doubt its your bearings in the sc. if the rotors were crashing with the case, it would make a much more audible scrubbing sound.
check your belt tensioners.

[endy1]

Have the same sound on mine and dont think the sound comes from the rotors hitting eachother. If they would, the would wear of so the sound would go away. Id say its just a sound from the needlebearings.
My sound comes and goes and have done the for asfar as i know.

[bgoetz]

I mean one benefit of the “do nothing” approach is if something finally does shit the bed I can update this post and let everyone know what is causing it 😂

[2by2handsofblue]

I mean one benefit of the “do nothing” approach is if something finally does shit the bed I can update this post and let everyone know what is causing it

Well thats one way of going about it. If it gets worse than there could be something worse

we are the borg! resistance is futile.

[sepheroth86]

Slip the belt off and see if the noise goes away?

Not sure how picky these cars are when doing such a procedure.

[djn876]

Does removal of this plate allow one to reach the output flange of the blower?




You need to access the output flange as seen in the picture below.

Not sure what you mean by "output flange", but no, that's a dampener plate, it is not covering any holes.

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[Mfryman1]

Although I'm kind of Reckless on my troubleshooting skills (40 years) taking the belt off would stop spinning the SC and if you still had noise then that would point towards the tensioners. I just replaced mine because of the 2 second noise at start after sitting overnight (114K Miles) but it was not a thumping noise like in your video. There are lots of videos on the timing chain noise. Listen to this at 2.05 seconds and this is typical of a rattle because of tensioner wear and lack of holding oil pressure overnight,

https://www.youtube.com/watch?v=T-xJECF9J7Q

The removal of the above mentioned cover reveals nothing as it just houses the rubber grommets for the engine cover
SC20210509_192804small.jpg

Counter sunk bolt holes circled for the flat head screws (T30) that hold the cover on, I just painted the SC so they are taped over.

IMO the noise is not the timing chain tensioners but could be a timing chain issue because of a busted guide. Again taking the belt off will eliminate the SC. I have heard nothing of the bypass valve causing a noise but I have not looked either.

Here is the link to SC, online. I looked on my account and for some reason it does not have my order for the bearings.

https://superchargersonline.com/

[email protected] really could help put a kit together for you, TSV 1320 Eaton, Shoot him a e-mail

[bgoetz]

Thanks! I will maybe pull the belt off. It seems to sort of come and go and I really hate chasing noises, it can make ownership no fun. That said if there is something I can do to avoid a big bill then it makes sense to be a bit more proactive. I really do not think it is the timing chain unless it is somehow transmitting through the engine. I have put the stethoscope directly on the timing chain cover and hear nothing but a smooth operating timing chain. Today when listening I heard more noise from the plug area on the back of the supercharger.

[Fresh.S4]

you dont think for the slightest moment that its coming from the front?
are you running the correct size belt? look at what your idler is doing, is it all jumpy and spazzy?

[bgoetz]

Just to update. Pulled the SC belt first, no change in the sound. Pulled the serpentine belt, the sound got noticeably quieter, but is still there. So I am stumped. I feel like that leaves me with the crankshaft pulley, timing chain issue like a worn or broken guide, or an internal engine issue. Unless I am missing something. I just can’t figure out why it gets quieter with the belt off unless the decrease in load on the engine makes it slightly better.

[bgoetz]

So thinking of other issues that it could be, it could be something with the clutch. It does seem a bit louder when I listened to it under the car from the wheel well area. The clutch pack is opposite the crank pulley so perhaps the slightly different load causes more sound. This video sound almost exactly like my sound only this is much more noticeable, but it is the same sound.

https://youtu.be/7jJE27D6oRQ

[sivletho]

That sound has to do with the timing chain system
you have 2 upper timing chain tensioner and guides(mine was broken and it was making that noise) and you have the lower timing chain i think you can hear them by the wheel wells if not I would jack the can up on stands and hear if it’s Louder from underneath


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[Mfryman1]

Hello again Bgoetz, I listened to the u-tube and I agree that the sound is almost identical but louder than yours. One question you never shared what kind of Tranny you have. The DSG 7 speed tip-tronic trans Code OB5 or TNY does have the dual mass flywheel the gentlemen is speaking of in the video. What year is the vehicle, have you the information on the VIN # usually found in your trunk under the spare tire area. See pic below.

Audi Trunk.jpg

This is a pic of the Dual mass flywheel he is talking about


flywhel pic.jpg


This is a pic of the photo I used to get a list of the parts to replace the timing chains, and tensioners. Note I was not asking for the top tensioners and the top 2 small guides as I already had new

timing needs.jpg


Sadly with the 3.0 to put your eyes on either system you will have to pull the engine and separate the trans from the engine as the timing system is at the rear of the engine. If you decide to only drop the transmission you can unbolt the 5 bolts from the clutch plate and separate it and drop the transmission only but the DSG is massive in size and weight, the exhaust system is in the way as are the CATS. I learned the hard way that it is just easier to pull the whole thing out. This is how the front of my car looks now as I am almost ready to reinstall the engine and transmission.

front now.jpg

[bgoetz]

Thanks for all of the help so far! Mine is a 2011, I will grab the code, but I am fairly certain that means it has the DMF. Seems like from what you are saying is that regardless the engine has to come out, so maybe the route would be pull the motor, check the DMF if it is bad stop there and just do the DMF. If it isn’t bad keep going and do the timing chain.

Maybe there are some who would say do it all while the car is apart as well, but I have a feeling that might be a hefty bill.

[Mfryman1]

Depends on how many miles, I had 114K on mine so I did it all, timing wise. Cost for the parts about $1.2K
If you do the rest water pump, thermostat, PVC, intake valve cleaning, All new rubber O-rings and gaskets Total $2-2.5K

[bgoetz]

Just to update, I have been pretty busy lately and haven’t focused much attention on this issue. I believe that I have determined with 95% certainty that it is the DMF because the sound goes away when I put the car in gear and comes back the moment that it goes into park. Also I occasionally get a mild clunk when shifting to 1st and 2nd. Does anyone have any details of what it takes to fix this? I have access to a lift and shop. Looking around I can’t even seem to find the DMF for sale, all I find is the manual tranny one, unless they are the same.

Any perspective for the risk of running it like this? Seems worse case it flies apart and messes crap up in the bell housing, which admittedly isn’t great. I am going to get the car on the lift and investigate more ASAP, maybe there is an access port where I can use a bore scope to take a look.

[bgoetz]

Finally confirmed it is 100% the DMF or perhaps the clutch pack? Putting it on a lift and pulling the plastic shield from between the tranny/engine clearly reveals the rattle. The car shifts fine except for a slight clunk at times into 1st, which does seem to be related to whatever is loose. Not sure if I will fix it right away or roll the dice and just monitor it to see if it gets any worse. I will keep things updated if it blows up or when I decide to fix it 😂

Starting a new thread specific to the DMF issue since this originally started as a potential supercharger issue.

[itsapoolday]

Hey there - I now this is now old but I have been heaving the same noise in my 2015 S4. Did you end up going through with the fix? If so, what did it entail?