lifter clatter - what's yours sound like

A6 All/ S6 All
#1

My '07 has had an audible valve clatter from like 1400-1800rpm’s since I got it @ 93k last year.

Doesn’t at all change in characteristics whatsoever in any circumstance, it’s mostly audible with radio off and light throttle cruising.

What do yours sound like?

I’d be concerned if I were able to manipulate it with revs, getting it to change in pitch / frequency with load or revs… it’s not there, it’s there, it’s gone as the revs go from idle to low rev to higher revs - if that makes sense.

I’m thinking it’s normal, but really need to hear another and figured I’d start by picking yers all’s brainz.

TIA, germs.

#2

Interesting, I’ve never noticed any valve clattering sounds at 1400-1800, I’ll give it a closer listen when I drive it tomorrow

#3

It’s lifter clack - very slow, very audible, @ 111k now with zero change better or worse

annoying when my muscle car friends are with me and ‘aptly’ suggest hey dude you need to run 20w50 in here for that

um… yeah - no.

#4

Couldn’t hear anything in my car today. My car definitely makes some aggressive sound from about 3k-4k, but I’m fairly certain it’s not the same thing. In the RPM range you specified, my engine is quiet as a church mouse. Well, the valves are anyways.

#5

The lifters are hydrolic and its incredibly unlikely that its anything with the valves. Not to completely rule out the lifter notion but its likely not lifter clack. If there was an issue with the lifters were bleeding down leading to a clacking noise its going to be seen in a larger rev range. Also the lifters once pumped up if you will… are under constant contact the only time they would clack is again when they bleed down.

The other possiblilty it could be is part of the mechanical injection that already makes enough noise that my push rod domestic buddies think there is something wrong with the FSI cars. The car would probably be in the enrichment zone there at the rev range you talked about and that noise wouldnt rise or fall speed up or slow down with rpm. The other think you could be hearing is the camshafts shifting. If you have a keen ear you can hear them shifting from full open almost all the way to full back I generally hear it as more of a flutter but some might see it as a clacking.

All in all you hear the noise and I dont want to deminish what you might be hearing. I just wanted to try and give you a few things to think about to help maybe take your worry away with regards to the noise

#6

thanks for the replies and insight gents, appreciated

I’ve been in tune with engines my whole life and like to think I’ve got a good ear

Yes, underhood it’s DEF injectors… suckers are loud. It sounds normal to me, just more audible as if there was less sound deading up there… but only @ that certain rev range and under cruising condidition. It’s engine speed dependent and a very slow rhythmic clack. I’m leaning toward injectors too.

Maybe due to my APR tune…

thanks again - wanted to confirm I’m not crazy (ier, than I already is be)

#7

a’ight

got together w/ my local bud and listened to his - his is silent

had him give it revs while I had an ear underhood

it’s NOT the valvetrain

it’s decidedly coming from the intake manifold.

I know there’s flaps in their that actuate to adjust runner length. My manifold was replaced @ 35k (now 111k).

What is in there that would make a reciprocating noise like that?

The only CEL I occassionally get is 1071 or 1075 or something - slightly lean or something.

Car runs like a scalded cat otherwise.

Any further insight here gents?

TIA.

#8

Sounds like same issue with broken flap in intake manifold based on the diagnosis and codes. I had to replace my intake manifold with the new OEM redesigned version to correct it

#9

From my experience with multiple different Audi models, engines, and configurations. When you can hear a noise like a rattle, crackle, squeak, squeal, or other noise at a very specific engine rpm usually between 1K to 2K rpms it is usually always something to do with the belt tensioner or idler roller going bad. Sadly there is no room to do the old timer trick where you take a really long screwdriver and stick the end of the screwdriver on the side of the spinning pulley then listen for grinding through the screwdriver. I have diagnosed a bunch of bad bearings in the tensioner pulley or idler roller that way. You could do that if you were willing to move the front end into service position and then run the engine but that is a lot of work on these C6 S6s. Some cars get so bad that when I turn the pulleys by hand it is noticeable that they don’t spin freely. I actually just finished up a big B7 S4 rebuild that the serpentine belt tensioner and idler roller along with the clutch throw-out bearing were shot to the point that you could feel a noticeable drag when spinning any of those parts by hand.

To get the intake manifold off anyways, you are likely going to move the front end into service position so it is worth checking the condition of the serpentine belt tensioner and idler roller.

#10

thanks

while I know what you mean, for this I really don’t think that’s it

I can FEEL the clatter with my hand on the intake mani - and hear it right there

anyone?

can I just run like this and live with it - or - is something in there going to let go / get ingested / etc.?

#11

exact same as you Schultz; same symptoms, same rpm range. Although mine rattles through a larger range sometimes. Honestly it sounds a lot like something detonation related like a knock/ping but I’m fairly certain those would throw codes?!

Also, the car runs like absolute dog crap when cold now. misfires, stumbles, SAI errors…wheeeee. If I run around in “D”, performance is in general bad. Manually shifting immediately changes the behavior as does driving in S. I’m wondering if my calibration is bad on that side of the program? There’s a definite difference between the two.

Gonna have to suck it up and buy an intake. Problem is, it’s not just the $2k for the intake, but the additional labor and downtime for a carbon clean that’s got me worried. And the inevitable injector, plug and coil failures that seem to follow…

#12

ah, nice not to be the only outlier here - thanks for sharing your experiences

yeah, mine does do it up thru 2200-2400 and then either goes away or is drown out by other normal engine noises

mine did have an occasional idle stutter on cold starts last summer which would clear out pretty quickly and has since gone away - would leave a misfire code, but that’s it

car idles and runs great, power is violent

agreed on replacement manifold price concern and related peripherals

what’s in there that’s reciprocating and making the noise?

again - can just live w/ it, or is this something that will eventually self destruct or cause other damage?

trying to evaluate the hold / punt decision

shame, I really adore the car - it does everything I ask / expect of it and covers all necessary bases quite nicelike

#13

Honestly, the rattle has me stumped - it’s most definitely coming from the “intake area” but I cant verify. The actuators and sensors are operating normally, and I can feel when the valves change over - there’s a marked difference in performance… What I don’t get is even if they’re broken, it’s an intake the valves see vacuum - you’d think it’d be enough to hold things in place until they’re moved. I’m honestly glad it’s the intake tbh…just sounds like a broken lifter.

I’ve got no choice but to limp along as is - the car’s running great otherwise. I bought this car knowing carbon clean had to be done and intake replacement was probable - wheels, tires, exhaust and tune kinda chewed up that part of the budget :wink:

I’m going to try and get the injectors cleaned/serviced in conjunction with the carbon clean - I’ll probably buy 3-4 of them to replace the ones that’ll probably break coming out and send them off with the other 10 and hopefully end up with a good matched set. :S Also need to do the tranny fluid, pulley and idler and brakes.

BUT after all is said and done, it should be good for another 100k miles with little in the way of major service. While it seems like a lot of $ to throw at an almost 10 year old car, my god is this car brilliant and it’s still a $92,000 car new that I’m enjoying for less than $20,000.

Don’t give up - you’re halfway to trouble free nirvana!

#14

well said - I’m in that exact same boat, minus the wheels :sunglasses:

agreed, elated it’s NOT lifters - which is exactly what it sounds like! That’d be… spooky. Yeah, um… no.

#15

The flaps on the intake could be part of the rattle but the internal flaps for tq dont switch over till around 4500. The lower port flaps change over in the 2000 range a little higher with light throttle and lower with heavy throttle. The flaps could just be at a point if there broken that they are rattling under the vac increase.

If you have bad cold starts and you have changed the injectors or cleaned them then your probably looking at an intake issue. The broken intakes cause bad bad cold start and cold running conditions add in old uncleand injectors and carbon your car will be hateing the cold and cold starts.

#16

thanks - pretty much what my ignoramus was speculating regarding the internals of the manifold

seems like a just live w/ it issue to me :sunglasses:

f’n car hurts my brain rattling around in mah noggin (tiny, so lots of room for movement?), it’s violent - so much so I can’t launch in Tip, it’s painful. Always in D, then slide it to Tip after the 1-2 upshift

no idle issues here since those few random misfires last summer - yet :sunglasses:

thanks again for everyone’s thoughts, much appreciated!

#17

soooo… The car was worse than ever cold starts; pretty sure I’ve got at least 3 clogged injectors or coils going bad. For giggles I did 7gal of 101 and the rest 91octane and a bottle of Techron; the rattle is all but gone meaning it had to have been engine knock I’m thinking.

I usually buy gas at the same two places - maybe I just got a bad batch of gas and/or the supply truck forgot to add the additive package to the 91 tank. I’ll go back to 91 the next tank and see if the knock returns. If so, I’m wondering if I got the right tune; I selected 91 instead of 93, and we’ve got very inconsistent 91 here… Are you stock or OEM on your ECU Schultz?

#18

I thought he had the APR tune at one point but I might be wrong.

#19

GAS and bad injectors with carbon build up would make the most sense. PEAK TQ range issues are common with OEM stock RS4s with carbon build up and poor injectors.

If you put in good fuel report how the cold starts are that should help tell a little more of the story.

Winter blend fuels are terrible depending on where your located add to that the possible water content increase in the cooler months and you are going to really notice it. I know this winter blend fuel issue has been a issue before in the past both for OEM and tuned guys.

#20

yes APR tune here for me

mine is most CERTAINLY the intake manifold

my mechanic said he’d gut it for me and do a carbon clean - if I decide to keep the car I’ll do the Phenolic then too… gdamn Quattroporte’s still catching my eye :sunglasses:

we’ll see

anyone gut a manifold? He said it’d throw codes and my tuner friend would have to write a code around that but otherwise it’s a simple solution