Grating noise

Hi, My A4 2k has started making a grating noise from about where the exhaust cat is situated, the noise is only present when i start from cold, the noise
dissapears after about 2 mins, any ideas?? Thanks.
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check the meaning wrote:

Need more information: What engine / transmission? Does it make the sound when moving and in gear? Does it vary with engine speed? Noise when brading? What speeds does it seem worse? Any error codes?
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Sorry for lack of info...... Its a 1.8 se manual, the noise is only there at start up from cold, dissapears after a couple of mins driving, there is no noise after that, drives well, no noise when braking or anything else, only at start up. Sounds like a "rattling / grating" noise. then dissapears when engine warmed up. also no error codes. HTH.
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wrote:

Could be the heat sheild rattling until it warms up and expands a bit. Could also be the insides of the cat doing the same - rattling until it expands. The heat sheild is easy to check, just see if it moves around when cold. If it is the inside of the cat coming apart, I would assume that you'll see a Check Engine Light soon, as it will clog the exhaust system.
Dan D '04 A4 1.8Tq MT-6 Central NJ USA
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This is a multi-part message in MIME format. --------------060707000002020805090902 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit
Dano58 wrote:

</pre> <blockquote type="cite"> <pre wrap="">check the meaning wrote: </pre> <blockquote type="cite"> <pre wrap="">Hi, My A4 2k has started making a grating noise from about where the exhaust cat is situated, the noise is only present when i start from cold, the noise dissapears after about 2 mins, any ideas?? Thanks. </pre> </blockquote> <pre wrap="">Need more information: What engine / transmission? Does it make the sound when moving and in gear? Does it vary with engine speed? Noise when brading? What speeds does it seem worse? Any error codes? </pre> </blockquote> <pre wrap="">Sorry for lack of info...... Its a 1.8 se manual, the noise is only there at start up from cold, dissapears after a couple of mins driving, there is no noise after that, drives well, no noise when braking or anything else, only at start up. Sounds like a "rattling / grating" noise. then dissapears when engine warmed up. also no error codes. HTH. </pre> </blockquote> <pre wrap=""><!----> Could be the heat sheild rattling until it warms up and expands a bit. Could also be the insides of the cat doing the same - rattling until it expands. The heat sheild is easy to check, just see if it moves around when cold. If it is the inside of the cat coming apart, I would assume that you'll see a Check Engine Light soon, as it will clog the exhaust system.
Dan D '04 A4 1.8Tq MT-6 Central NJ USA </pre> </blockquote> Dan's reply is probably the best guess but I have one other idea.<br> <br> It could be the starter bendix sticking and not allowing the starter to disengage from the flywheel. If it is this it would be very loud until it disengaged and probably reving the engine a bit would force it to quit suddenly.<br> <br> </body> </html>
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</PRE> <BLOCKQUOTE type="cite"><PRE wrap="">check the meaning wrote: </PRE> <BLOCKQUOTE type="cite"><PRE wrap="">Hi, My A4 2k has started making a grating noise from about where the exhaust cat is situated, the noise is only present when i start from cold, the noise dissapears after about 2 mins, any ideas?? Thanks. </PRE></BLOCKQUOTE><PRE wrap="">Need more information: What engine / transmission? Does it make the sound when moving and in gear? Does it vary with engine speed? Noise when brading? What speeds does it seem worse? Any error codes? </PRE></BLOCKQUOTE><PRE wrap="">Sorry for lack of info...... Its a 1.8 se manual, the noise is only there at start up from cold, dissapears after a couple of mins driving, there is no noise after that, drives well, no noise when braking or anything else, only at start up. Sounds like a "rattling / grating" noise. then dissapears when engine warmed up. also no error codes. HTH. </PRE></BLOCKQUOTE><PRE wrap=""><!----> Could be the heat sheild rattling until it warms up and expands a bit. Could also be the insides of the cat doing the same - rattling until it expands. The heat sheild is easy to check, just see if it moves around when cold. If it is the inside of the cat coming apart, I would assume that you'll see a Check Engine Light soon, as it will clog the exhaust system.
Dan D '04 A4 1.8Tq MT-6 Central NJ USA </PRE></BLOCKQUOTE> <DIV>Dan's reply is probably the best guess but I have one other idea.<BR><BR>It could be the starter bendix sticking and not allowing the starter to disengage from the flywheel. If it is this it would be very loud until it disengaged and probably reving the engine a bit would force it to quit suddenly.</DIV> <DIV><BR><FONT face=Arial size=2>Cheers guys,&nbsp; I think danos diagnosis is more close to the mark, i will check it out</FONT></DIV> <DIV><FONT face=Arial size=2>many thanks for your replies........&nbsp; :0) Ps did you know that you are posting in HTML ??</FONT><BR></DIV></BLOCKQUOTE></BODY></HTML>
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The secondary air pump will only run for the first 30 to 120 seconds when the car is first started. The ECT will tell the ECM how long to keep the pump on. The pump is low on the car and I have seen water get in the pump and eventually cause the motor to get louder becasue the bearings dry out. Start the car (do not drive) and go up front and listen to the fan. If the noise goes away when the fan stops than the fan needs replacing. VW has a similar problem and when water gets in the (colder climate) the pump will freeze and blow the fuse.
On Sun, 09 Dec 2007 23:51:42 GMT, "check the meaning"

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