I recently posted a write-up on a noise I was experiencing, buzzing/ loose chain noise under de-acceleration. The problem (buzzingnoise) turned outNOT to bethe tensioner I was professionally told and quoted on ($1200 job). The problem was the wastegate valve on the turbo. (not actuator) so unfortuantely I could not just replace the actuator; the whole turbo had to be replaced. Let me say thank God I did my research onTHIS FORUMand chose to replace the turbo myself and not some Audi mech. that would have charged an arm and leg for a mis-diagnosed job. Per someone else's instructions, I was able to run the car, pinpoint the noise while reving the engine manually and add tension to the wastegate actuator arm on the turbo my means of a coathanger which eliminated that buzzing noise under load!! You guys freakin RULE!!

I justgot done swapping my old turbofora used, low mileage Passat K03 ($300); even had the chance to upgrade to a used K04, but chose not to. I know, I know...that was my exuse and chance I blew it. I used compressed air to spin the internals and everything sounded smooth, no grinding,shaft had minimal play, fins were in good shape and the wastegate valve was tight!Finished the install last nightalong with the intake mod upgrade and WOW what a difference...I finally have boost!! Idle is back to normaland the car is amazingly responsive!!

While removingmyold turbo I had oil dripping out of every hose and the internals sounded like crap when spun. The wastegatevalve was shot, bearlymaking contact with the housingwhich explains extremepower loss in mid-high range. I must have been driving around with a bad turbo for a while to not notice this difference in performance.This would also explain the bad MAF-codeI kept throwing as well.

All in all thediagnosis and turbo swapwasa success through the help of everyone's input and posts on this forum. The write-ups and step by step instructions are invaluable; I savedloads of moneywhile gaining the experience, knowledge and confidence to pursue furture repairs andupgrades. Thanks again.

 

Weird cause i have the exact same noise but mine comes from the back of the engine right where the chain is. where was ur sound coming from? and why cant u just replace the wastegate?

 

My initial thought was that the sound (loose chain noise) was the timing chain tensioner, thats why I replaced it. After I replaced it, I had the same noise, so I did some more research for similiar situations and noises that people were having on their 1.8t's. Then I came across a similiar problem/ noise someone was having which turned out to be the wastegate valve in their tubo. I then checked mine and low and behold that was definitely the source of the cause. The waste gate actuator, if goes bad, can be replaced b/c that is the vacum/valve device with rod attached to the turbo. The actual wastegate is the valve inside theexhaust side of the turbothat is attached to the turbohousing which iscontrolled by the actuator/ rod itself.If your rod is loose at allit's either goingto be your actuator which gone bad or the valve itself. My valve was really loose and just rattling inside; I'm assuming the turbo then was not containing boost atall, it was just bleading out.

 

dang this is a great post to the effectiveness of audiforums. glad everything turned out ok for you

 

Yes indeed! I am just happy and relieved I did everything myself and could reference instructions and everything else I needed from this forum. I almost wasted a lot of money in stealership fees for a problem that they couldn't even diagnose. I swear, I have such a hard time confiding in service these days. If I don't fix it myself I feel I'm just wasting money in someone else's ideas.