Heat Shield rattle....may need tech help
 

Hey all,

So ive searched and searched and everything i've found says my rattle may be caused by a loose heat shield (which is what the Audi dealer told me it could be).

How would I go about getting to a heat shield? Does anyone happen to have a picture?

RE: Heat Shield rattle....may need tech help
 

Its probably the heat shield on your cats. Not really a big deal just annoying. Take it to a muffler shop and ask them how much to fix it. They should quote you for free.

RE: Heat Shield rattle....may need tech help
 

im pretty sure its not the cats....i stuck my head under the car and its definitely coming from the engine area. I'll verify it tommorow though.

RE: Heat Shield rattle....may need tech help
 

I have the same problem! Its annoying as all hell. Mine rattles only when I leave a red light. I have the 6spd so when the clutch starts tograb and then car rolls forward the mystery rattle begins. I'll check in a little and get back to you. I've been meaning to do this for some time now!

RE: Heat Shield rattle....may need tech help
 

Hi,

I have an 01 A6 2.7T that has this annoying rattle as well. Engine area - verified not the timing belt but that's what it sounds like - something loose. Also doesn't do it ALL the time. I notice it most when I use the highway. Sometimes it just seems to come on.

Could it be the heat shield too? Same area?

The Lansing, MI dealer WAS NOT able to diagnosis it and sent me on my merry way WITHOUT fixing it and charged me only for their labor (reduced at least).

What kind of noise is yours making?

Thanks

RE: Heat Shield rattle....may need tech help
 

RE: Heat Shield rattle....may need tech help
 

Not to be left out of this party, I have the rattle as well. Can't speak on your specific case Coors, but I completely removed my belly pan due to damage and the rattle is still there. Haven't replaced the pan yet. In my case (01 A6 2.7T) it also only occurs sometimes. It seems to more prevalent when the car or outside temp rises. In the morning when the car and outside air temps are lower, it almost never happens. The intensity of the sound also varies. At it's worst, I can even sometimes hear it when accelerating at highway speeds. I haven't had the chance to take it in yet for inspection of the heat seals. Anyone know where on the car they are located? I'd much rather do my own visual inspection if that can save a shop any time in finding/fixing the problem.

RE: Heat Shield rattle....may need tech help
 

There are also heat shields that surround your turbos. I have seen broken tabs on these heat shield. These tabs contain a screw to secure it. When these tabs break due to rust, you of course can't secure it and therefore a rattle! Not sure if this is your issue, but I've seen this in the flesh!

OOOO

RE: Heat Shield rattle....may need tech help
 

I have an exhaust rattle myself and I thought it was the cat.
Took it to the shop where they told me it wa the exhaust pipe which has an inner pipe.
they drilled a couple of small holes and welded thie inner and outer pipes together.
this did not work as there is not much accesebility to the pipe.
The alternative is a new pipe ( $800.00) at the dealer. or remove and weld the old pipe( about $70.00 )
I am going to have it removed and welded soon. I will post the results. BENG

RE: Heat Shield rattle....may need tech help
 

i had the rattle too but mine turned out to be a cat issue....audi will replace the cats for free if your car has less than i think 75k miles and newer than a 2000.

RE: Heat Shield rattle....may need tech help
 

I thought it was my cat, but the shop told me that if it was the cat you should be able to hear it by simply banging on it,(engine off). Thusly, it was determined that it was the inner pipe. beng

Hey guys, im back with an update:

I took the car in to finnaly get this thing fixed and it was officially the heat shield.

Evidently there was a crack where the heat shield bolts only the undercarriage which (after running for a bit) would loosen up and start a shakin'. SO, I have a new heat shield on the way and will have it replaced within the next week or so.

The dealer did suggest that I could probably take it to an exhaust shop and they may be able to weld it up and remove the noise. BUT, seeing as most shops around here employ people who like nascar and dont know the first thing about german cars, I thought id pay the extra coin and have the dealer just get me a new one.

Hope this helps, ill update again after its replaced and confirm the fix.

Hi,

I realise the age of this thread :D but for anybody who originally posted on it (or anybody elkse of course), did the noise sound anything like this?...

http://www.youtube.com/watch?v=6CUMpEQp5-w

I already have a seperate thread on my issue but for what its worth, with any luck and all that :(

I had a very similar problem with my wife's A6. Here's a quick list of the things I tried that didn't work:

I did some research and read that Audi used special "double-wall" exhaust tubing that could come loose and rattle on the inside, making it hard to identify the source. Aha! Simple. All I had to do was remove each front pipe and cat and see if they rattled when I hit them with a hammer. It turned out to be a bit of a challenge to remove the manifold bolts, but I got each pipe off (except for the O2 sensors, so they were still attached by the wire harness), but there was no sign of double-wall anything, and I couldn't make them rattle with any hammer I owned. Back to the drawing board.

My wife was already annoyed, but I assured her that I was close to figuring it out, and I got back to work. My next attempt involved cutting the bottom of each cat open to see if the catalyst had broken loose inside. I found out that they're surprisingly difficult to cut through! Must be the German steel. The passenger side cat had several loose pieces of catalyst inside. Jackpot! I removed them and had my brother weld it closed again. As a formality, I cut the driver side cat open, and to my surprise it was completely empty. Weird. There was an O2 sensor right behind the cat, so the catalyst would have to have broken up into tiny pieces to get blown further down the pipe, and that seemed unlikely. My brother welded that one back together while I tried to figure out where the catalyst went, but I decided that I didn't really care as long as it was fixed. Imagine my disappointment when the rattle was just as bad with the empty cats when I put everything back together.

Next I removed the entire exhaust system behind the couplers to see if there were any chunks of catalyst rattling around in the three mufflers. Of course there weren't, so I put it all back together again so my wife could continue enjoying the obnoxious rattle.

I decided to see what it would cost to buy new pipe and cat assemblies. Based on the dealer prices, it would have been less expensive to buy another A6 than to replace the cats, which was no good. Instead, I bought two universal cats (about $60 each) to replace the stockers. It wasn't easy to cut the old ones off, but when I did, I found an important clue. Someone at Audi thought it would be a good idea to add an extra triangular piece of steel in the front of each cat where the pipe diameter expands to the full cross-section width. Although the rest of the car seems to be built like the proverbial brick outhouse, these pieces of metal were apparently only held in place by a couple of spot welds. Once those failed, they turned into some kind of super-resonators that rattled crazily at most engine RPM's but were strangely silent during any manner of troubleshooting.

The good news is that welding in the universal cats took care of the rattle, my wife was happier with the car (and with me), and I was free to investigate the mysterious rattle that was coming from the engine compartment (it turned out to be the serpentine belt tensioner that grenaded on my wife while I was in Mexico on business, but that's another post).

Good luck with the diagnosis. I hope you find it sooner than I did.

Hi,

Cheers for your write up. It has certainly made me think of tasks to do, before a garage rapes me of cash.

On your wifes car, did it sound anything at all like my ratltle from my video?

The pitch was lower, but the frequency sounded the same. It was loudest when the car was accelerating from a stop, and it was less noticeable at speed, but that could have been due to the increased road noise. The piece of steel in the cat that was loose was roughly 3" x 4" in size, but whatever is making the noise on yours sounds like it could be smaller and lighter. Have you checked the metal clips that hold the O2 sensor wires onto the transmission case? If they come loose, the clips land on the cats and rattle (and the wires start to cook).