Engine Knock Noise
 

Hi All, I have 2000 Audi A8 and recently I ran into this problem that started out with noise coming from somewhere around the fan or engine. It sounded like something was in it's way. So, I tried couple mins later and still the same problem. So, I lefted over there and came back that evening and thought it might fix it but was same issue.

I got the car towed to dealer and had them run the diagnostic test. Guy from service department call me and told me that I needed Bank 2 Cam Adjuster replaced and the cost was $2,300.00. I am not very knowledgeable when it comes to the the car so I told him to go ahead and order the part and go with it. But than I decided to go and talk to the Mechanic in the back and ask him exactly what he was talking ordering the part for and what was the work they were performing. So, after talking to him he told me that this is the first issue that he thinks that is wrong with it. And that will cure the noise that is coming from the top of the engine but he is saying that the loud noise that is coming from the bottom could be something else and he can not tell me what it is until they do this first. He is saying it's also may need catalytic converter and the cost can get up to 7 to 8 thousand or might need whole new engine. Since this was kind huge amount for me and not knowing the exact problem and the cost I told them to hold off. I want to see what you guys think I should do. I got the report from dealer that states the following things:

INITIAL INSPECTION FINDS OIL LEVEL TO BE GOOD. STARTED VEHICLE, ENGINE IS KNOCKING, MIL IS ON AND FLASHING. MULTIPLE DTC'S STORED FOR CAM POSITION BANK 2 AS WELL AS CAT. EFFICIENCY, O2S OPEN/SHORT AND SEC. AIR SYSTEM FLOW TOO LOW. ELECTRICAL TEST OF BANK2 CAM ADJUSTER FINDS ADJUSTER OUT OF SPECS, RECOMMEND R&R OF CAM ADJUSTER WITH NECESSARY SEALS AND REINSPECTING.



Thanks,

Tino

The cam adjuster ($500 part) "could" likely be a separate problem from the "knock" in the engine, which could be a much more serious problem...for example: a "hydro-locked" cylinder (or 2) caused by head gasket allowing coolant into combustion chamber(s). Impossible to say without being there and a worst case scenario guess...and would involve changing the engine block.
Catalytic convertor and/or cam adjuster problems generally do NOT cause knocking in the engine.
What exactly are the codes? ...specific codes would allow a more educated guess.

Hi thanks for your response. I did not ask them what was the specif code. I was just sad and did not even thought about asking them the specific codes. The mechanic was nice enough to explain what was going on but he sounded like he did not want to open the whole engine. Some reason they wanted me to fix the CAM Adjuster first. The price you mentioned that was I came across when I did some research around on the net. I don't know what to do. My car is sitting at home for now but can't really find anyone to work on it and couple of the ones who I found they quoted me anywhere around 4-5 thousand. Thanks for any advice.

Hi All, I have decided to part out my 2000 A8L. Engine Knock noise I have not been able to get it fixed. So, I am just going to part it out. Where should I list the car, on ebay?

Is the noise kind of like a ticking noise that seems to follow engine revs in frequency? I've had a noise like that for a while now, I suspect it's a tappet noise. In the past I put oil system cleaner in it and that stopped the noise for a little while, I have since changed the oil and added more cleaner more than once but the noise seems like it's here to stay. Aside from the embarrassment, it doesn't seem to have much of a negative effect on the engine. I'm sure that something is wearing unnaturally as a result, but how long that will take I have no idea. I don't know how much life is left in my 01, but I'm going to find out.