Audi A6 2005 3.2 L Quattro
On this video, I hear strange noise from the throttle area. This is after I changed the engine valve cover gasket due to leak. On assembly, I broke and repaired vacuum hose. I also took the time to clean the throttle body. I put it back together and had the vagcom throttle adaptation. No codes registering.

The car hesitates and jerks on acceleration and highway speeds. I suspected a vacuum leak but I don't see or notice any. Do I need a new Throttle body which is very expensive or any part like MAF. I do have a Vagcom on hand. Im open to any opinion thanks

 

If you're running it with the air intake disconnected like that, it's messing with the ECU because the MAF readings will not be accurate. But.. Having fought a similar battle a couple years ago and throwing $600 worth of parts at it to no avail, check the spark plugs for any glazed plugs. A glazed plug or two will cause hesitations like that on acceleration and at speeds like you mention. If you haven't put new spark plugs in it recently and any of the plugs look like they are brand new, it is glazed. A glazed plug will produce a very weak spark and will not properly ignite the fuel in the cylinder cause a no-fire condition. I've found many times after an engine has a bad O2 sensor or has had a vacuum leak, you will invariably find a glazed plug due to the ECU trying make the engine run right by messing with the amount of fuel delivered from the injector. Sometimes there is so much air (lean) that it burns WAY hotter in the cylinder than normal. This amount of heat will glaze a plug in no time.

 

Thanks for the reply. I did changed all the spark plugs and ignition coils. But I will check again. But Do you think there is nothing wrong with the throttle?

 

It's really hard to tell without being there and seeing it myself. But check those plugs again. If you ran them in the engine while you had the vacuum leak, it certainly could have glazed one or two. One is enough to make it run ragged.

 

Another thing is if the car is misfiring slightly, the back pressure may be slamming the throttle valve closed and making that noise.

 

thanks Dave for your help
After changing the spark plugs, Check for vacuum leaks, countless throttle adaptation - acceleration kick down procedure by using the vcsd, changed the MAF (mass air flow) sensor - the condition remain the same. I bought a used throttle body for $60 on eBay just to help me rule it out - and presto - I found the problem. It was a malfunctioned throttle body. I probably messed it up when I tried to clean it. I guess the sensor is very sensitive. that clicking noise doesn't exist on a functioning body - should be moving smooth.