Stumped....

B6/7 S4/RS4
#1

I spent the past week (with vacation time in between) trying to diagnose what my “knocking” noise is. It came on after a long hot drive up 95 to my parents house last Tuesday. My mom noted a knocking noise coming from the front of my car, I got out and heard it too.

Not knowing what it was, I parked the car in the garage and immediately asked some B6/B7 S owners via text. JimmyBones suggested that it might be my knock sensor and I might not have torqued it down to spec. He also came by with a VAG-Com to see if I had any trouble codes, I had 5: two knock codes, two vacuum leak codes and another that slipped my mind. I broke down the front end and took off the IM, tweaked around with the knock sensors, tightening them to spec (also had to do some preventative maintenance while car was down).

Today, I put everything back together and went out for a quick drive; everything checked out find. Tonight, I drove the Avant home from my parents and heard the knock noise again.

Here’s the video:

[video]https://www.youtube.com/watch?v=DstkTl6WDtY[/video]

Did a quick google search and found this DIY video:
[video]http://youtu.be/XOc_PHblvZQ[/video]

At the moment, I’m hesitant to break down the engine again to see what the noise is. Is it possible the intake flapper went out? The DIY video manipulation sounds SORTA like my noise. What do you gents think?

#2

Well the intake flapper is vacuum operated so that may be the root of your issue. As mentioned in your AZ thread though, check the flapper linkage at the front of the intake manifold.

If you can have someone else start your car while you watch the linkage. You can also touch the linkage while the car is idling to see if it’s moving.

#3

…found out what might be the cause of the “knocking”, the timing slightly is off on the cams.

I brought the Avant to Jimmy’s place so he could have a look-see and yup, might have to look into getting the timing job done pretty soon.

#4

You’re in good hands with Jimmy. He knows his stuff and should have you back up and running in no time. Come back and let us know how it turns out. If you can grab pictures and as much as you can to help the next guy.

#5

Oh man that sucks. On the other hand… anything else to “add” while the engine is out? Headers?

#6

Headers!! YES! You won’t regret it! You won’t believe what they do for the torque curve.

#7

Trust me Gents, I would LOVE to put headers in but at the moment, its not in my favor, financially. I DID toy around with the idea of putting JHMs IM in, replacing mine as this might be doable. As of now, I’m piecing things together from JHM and ECS.

The ONLY “add” will be motor mounts, JHM LWFW-B7 Clutch combo (with $50 add on for stage 4 kevlar/ceramic), some ECS slotted rotors and AKEBONO ceramic pads; nothing in the extremes.

I guess my Avant will DEFINITELY be a keeper now.

EDiT:

Forgot to mention the other issues:

** leaky valve stem seals (obvious given considering how much oil I burn)
** possible scored cylinder, #6 (Leakdown test was performed, not the best numbers and not the worse numbers

My plan of attack is as follows:

Timing components
Head gaskets with valve stem seals
Clutch/FW
F/R brake pad update
Motor mounts

Debating on these:
Slotted brake rotors
JHM intake mani

#8

Mani is about a grand? Rotors another few hundred? Just thinking of ways to get headers by sacrificing other more easily replaced parts that can be done later

#9

Just think of the MPG savings with headers! They will pay for themselves in like 5 more years…

#10

Add in the diesel 6th gear mod and you’ll be saving the rainforests! I can’t find it but someone did a calculation (maybe saki?) comparing MPG’s headers vs no headers. It would actually pay for itself within a few years

#11

Damn S4’s. That’s a lot of coin.

Has anyone calculated the payoff on the TDi 6th gear?

#12

I put in the .53 TDI sixth gear in July, 2011. My revs at 80 mph went from 3200 to 2200. I didn’t notice a great improvement in mpg when I went with headers in the fall of 2013, but if I don’t get too aggressive playing on the interstate, I can get as much as 26 - 27 mpg.

#13

I would rather go back to the stock sixth gear. It is really annoying when going up steep hills/mountains like the rockies.

#14

Interesting. I guess one of the S4’s selling points was the way it delivers torque in any gear any time. I guess that diesel 6th gear is is a bit too much

#15

What do you mean by that Jimmy, could you elaborate a bit?

#16

Took suggestions about sourcing parts from difference sites like ECS, JHM, RockAuto, GAP and Amazon; put it together on a spreadsheet:

https://farm6.staticflickr.com/5237/14598150901_a7bd7d183d_o.png

I’m missing a few things like o-rings, seals, and required bolts so if any of you can provide me P/Ns for those items as seen in this JHM image, it’d be very helpful for my research:

http://jhmotorsports.com/shop/catalog/images/JHM_B6-B7_S4-Timing_Chain_Kit_INTERMEDIATE.jpg

Here’s what I priced everything at if I were to source “intermediate-like” parts on my own:

JHM Mechanical Adjusters w/ parts sourced from ECS minus all bolts, seals, etc = $1652
JHM Intermediate Kit W/ Mechanical Adjusters plus all bolts, seals, etc = $1575
JHM Mechanical Adjusters W/ parts sourced from GAP minus all bolts, seals, etc = $1433

Also, looking at the clutch/flywheel combo from ECS, 034 and JHM:

JHM: JHM LWFW + Stage 3 = 1600
034: SouthBend Stage 2 HD Endurance = 1400
ECS: SouthBend Stage 2 HD Endurance = 1428

Any of your thoughts on SB versus JHM brand?

Motor mounts would be the 034 Density line WITH resistors

#17

Slow, you want the JHM flywheel and clutch kit if you go aftermarket. Otherwise get the OEM B7 parts and be done with it. Every Southbend clutch kit that I have ever installed was total crap!

The TDI gear is worthless below 50 mph. Yes you can drive the car at 40 mph and around 1K rpms but it is a total slug. That gear is meant for 65mph+. Where I live it is mostly 55 mph zones on the highways unless I go forty five minutes away on a major highway so I am speeding everywhere I go almost. Then when I was driving through hills the engine bogs so bad that I had to either floor it or downshift to fifth gear to get up the hill. Finally the TDI gear drops the rpms right into the drone zone (1200-1900 rpms) for the FI exhaust. You can’t hear a damn thing when driving up a steep hill around 60 mph. I actually had to buy noise dampening headphones in Barcroft CA so that people could hear me over the phone.

#18

Go with the jhm r series clutch. I liked the feel more. I don’t think it’s more expensive.

#19

I was going to say the same thing. Get rid of the POS SAC system if you can.

#20

Not enough torque and it lugs so you have to downshift.