Nightlifephantom

Just to keep this thread updated so others who are having the same issue can follow up... I found a video on YouTube that sounds very similar to the noise I'm experiencing along with my misfires and rough idle. Turns out in this video, the sound is coming from the throttle body.

The Fix: Replace throttle body

I ordered a new one for my 4.2 a few minutes ago.

The Audi part number is 077-133-062-A

All search for that part number were a few hundred dollars. I contacted a manufacturer in Germany and he stated that the part number is interchangeable with 078-133-062 which you can find for less than $100

Video of sound from YouTube user:

Nightlifephantom

After further discussions with multiple manufactures for our throttle body, part 078-133-162 will fit our motor but the bore is 68mm, our stock throttle body 077-133-162-A is 82mm. Not sure on the less bore space and what I would need or if it will still work inorder to make everything work, so I went ahead and purchased the same stock throttle body part# 077-133-062-A.

tishi

Hi, after you cleaned Throttle, did you run Throttle Body Alignment (TBA)?

Throttle Body Alignment (TBA) - Ross-Tech Wiki)

for more info.

-tishi

Nightlifephantom

Ya! The throttle body noise was there before I cleaned it. After cleaning, I did the adaptation through VCDS... chatter was still coming from the TB. So I also tried disconnecting the battery for a while draining all power by touch the negative cable with positive cable for 20 seconds, then reconnected them... Started car... flap still chattering. I think it's a malfuction within the TB or gasket. TB is on the way and so is the new gasket.

isaac.reddinger@gmail.com

Has anyone had this issue with the 3.2 as well, or is it specific to the 4.2? Also, has this issue caused any plugs to foul?

Nightlifephantom

Honestly, this can happen to 3.2 or 4.2. Depends on the throttle body itself.

As for the spark plugs... I ended up changing them all even thought I changed them in February, they appeared to be fine, just minor carbon on them. Will be reusing when the time comes.

Nightlifephantom

Ok, so after the new throttle body is on... the throttle body chatter is gone but I still have the misfire bank 1, cylinder 1-4 and now noise from the manifold. At this point I'm almost certain has to be a disconnected vacuum hose somewhere. Taking the car to my buddy's shop tomorrow to do a full vacuum test/observation, I'll update soon.

Nightlifephantom

So I stopped by my buddy's shop today... we smoked out the vacuum lines using a smoke machine. There doesn't appear to be any leaks. Any one have any thoughts? Misfire cylinders 1-4, all bank 1. We were thinking timing chain? Broken guide? If anyone has any experience dealing with bank 1 all cylinders misfiring, please chime in.

Nightlifephantom

Ok, so to recap I'm having misfiring issues.

Attempted fixes so far in order:
- Replaced bank 1 and bank 2 rear heated oxygen sensors
- New spark plugs
- New coil packs
- Cleaned MAF and also checked idle with out MAF connected
- Seafoamed gas tank, manifold vac, crankcase
- Fresh new oil change and oil filter
- Replaced throttle body
- Replaced entire intake system with aluminum pipe with stock MAF and with K&N closed induction system filter
- Did a smoke test for the vac lines

Today, I started my 4.2, went for a drive then ran VAGCOM... these are the current results.



There is a thumping noise coming from bank 1 valve cover. Here is a video:


RPM's also stutter while driving. Here's a video:



So right now... Cylinder 1, 2, 3 misfiring and there's also a strong smell of gas when first starting the car. Any help would be appreciated.

hrc4u

sounds like crap.. :O
whats your block 93 values in vcds?
edit: whats your fueltrim numbers? block 32 and 33?
/H