What year is your car? Is the check engine light on? How long have you had this problem? At a minimum, take your car to someone with a VAG-COM to pull any stored codes (or go to Autozone and have them pull the codes). Report back with the codes. If you are having ignition problems (i.e. misfire, detonation or pre-ignition...detonation is different than pre-ignition but has similar symptons, here's a great articale that explains the differences: Detonation and Pre-ignition.) you will have some stored codes. If this problem has been going on for a long time, you don't have pre-ignition.

If your car is '00 or newer (drive-by-wire), the ECU will pull timing and adjust the air/fuel ratio (by controlling the throttle and pulling timing) to avoid detonation and pre-ignition. On dbw cars, something has to be pretty f'ed to get detonation or pre-ignition.

Definitely, replace the DV. Bad DVs are infamous for causing surging.

Also, get rid of the Bosch platinum plugs. Put in (4) NGK BKR6E (around $1.50 each at Advance) or Bosch F7LTCR copper plugs (you will probably have to order these).

If you are worried about detonation or pre-ignition, do some logging with VAG-COM. Log blocks: 11, 20, 32 together (to check for proper maf readings, timing correction, and proper air/fuel mixture), 15 & 16 together (to see if you have any misfires and what cylinder(s) are misfiring), & finally log 115 to check actual versus requested boost.

 

My car is a 2000.

And i only noticed this sound after i did my DIY airbox mod, and i noticed it even more after i chipped.

I live in canada so autozones outta the question. I dont have a Check engine light, and i only hear this sound after about 2000 rpm or when the turbo starts spooling.

oh and with regaurds to my spark plugs, these arnt the normal bosch platinums, i paid like $22 CAD a plug their the ones with the the contact on the side and not above the platinum element.

 

You bought the platinum +4 plugs right? The problem is that platinum plugs have real small electrodes. These are problematic on turbo charged cars. They may run fine but are known to cause problems with chipped cars. The Bosch F7LTCR plugs are multipronged plugs too but they have a big copper center electrode. Do a searchand you will find an explanation as to why big copper electrodes are better.

Since you didn't notice this until you did the air box mod, I'm going to guess that you are hearing the DV rapidly opening and closing under boost (very common cause of surging) but, get the car checked for codes just to be safe. I'm sure there is a canadian Autozone equivalent that will scan your car.

 

The plugs im using arnt the bosch 4+. They only have one prong, and it sits on the side of the plug rather than on top of the contact.

Ive been told it may be feed back from the DV and im hoping it is.

 

NGK BKR6E and BKR7E are what is recomended most for chipped/BT engines. The +4's are crap because they distribute the spark over 4 prongs which makes for a weaker overall spark. They were designed for the performance of a copper plug with the longevity of a platinum plug. If one prong gets corroded or fouls, the spark goes to the next prong. If you search you will find that Bosch isnt recomended in general as a brand, and that NGK BKR6E is best for chipped and BKR7E for BT for the 1.8t. A plug for a chipped 1.8t engine has to be gapped to a certain measurement which is near impossible to do with a multi pronged plug anyway.

 

well i had a mechanic look at it and he says its likley not detonation, becauase its not knocking or really pinging. He said it could just be the exhust sheild rattling. I hope it is but you know how with our luck its ussully not.

Also i seem to be loosing power for sure, boost seems strong someones and fairly weak at other times.

Im installing a boost gauge and im swapping out my DV004 for the 007 tommorow i hope it clears some of my problems up.

Well see what happens tommorow,

Thanks for all the replies.

Brandon Lau

 

Let me know how this goes for you. You may have just needed a new diaphram or a stiffer spring in the 004.

 

This is really strange. Since yesterday, during high boost/floorin it, i have the cracking/clicking noise from the front left/intercooler area of the car. Its deffinately not detonation but other than knowing that, i have no idea what it could be!!!!! ****!!! Its not all the time, but it happens. I'll get under there tonight for a looksee and vag it...
i dont notice any fluctuation in boost or power surging when this happens. STRANGE! I DONT LIKE IT. I highly doubt its DV or spark plug/combustion related now. Not to sound arogant, but this is so frustrating for someone so mechanicaly inclined! I love my audi, but i may have to let it go if these mysterious unexplainable noises keep happening... Its killing my ego. [8D]

 

could it be the oil cooler I have heard it before when pumping the power and the oil doesn't get round fast enough, just a thought because im not into turbos

 

the sound is like taking a pen and tapping it on a desk really fast, except 20 times louder coming from the drivers side front wheel or somewhere around there... I also highly doubt its a heat shield or anything else thats been mentioned so far.